Re: [solved] Re: Live recording

[Rodolfo Medina]

Jeremy Nicoll  writes:

> On Thu, 17 Aug 2017, at 08:57, Rodolfo Medina wrote:
>> Jeremy Nicoll  writes:
>
>> > You do realise that merging files, adjusting balance etc are all possible
>> > with sox?
>> >
>> > One reason I do that sort of thing with sox is that by keeping note of the
>> > commands I used to do each stage, I automatically document how I
>> > manipulated a set of audio files.  Documenting anything done via a GUI as
>> > in Audacity is a great deal more difficult.
>> >
>> > It's worth documenting what you do so that if necessary you can exactly 
>> > repeat the process at a later date.
>> 
>> 
>> Thanks...  In fact, what you suggest is exactly what I wanted to do but
>> didn't manage to...  In fact, suppose I have two files: piano.wav and
>> voice.wav, created by sox in recording piano and voice respectively,
>> simultaneously.  piano.wav is a stereo file, with the two channels, left and
>> right, inside it; whereas voice.wav is a monophonic file.  When I put them
>> together to create the final, say, result.wav, I must properly allign them.
>> Now, Audacity makes this job easy thanks to the graphical possibility of
>> seeing the waving forms and magnifying them.  Instead, with sox, I tried to
>> use the `delay' option with no success.  Maybe can you suggest a better and
>> proper way to do that...?
>
> I've never tried that.  The sox mail list is a good place to ask for sox
> help.
>
> One thing I'd suggest (since sox is potentially complicated) is that instead
> of trying to use sox with one command that does everything, you try to do it
> in stages.  That way you can check that what you get at the end of each stage
> is what you expect.  Sox has effects that will tell you about what is in a
> file.
>
> I think first I'd check simply that I could create a file containing all
> three channels, eg by:
>
>  sox -V2 --no-clobber -M piano.wav voice.wav threech.wav  
>
> The -V2 sets a fairly high level of verbosity; you might need -V3
>  
> The --no-clobber prevents sox from overwriting a file.  It's easy to get a
> command wrong and accidentally destroy an original file; personally I work on
> copies of files AND use --no-clobber.
>
> -M tells sox to merge the files.  You should end up with a 3 channel file,
> with the piano audio on channels 1 and 2 and voice on 3.
>
>
> If that works (and ironically, Audacity might be an easy way to make sure) I
> think I'd next try to make a file with the voice channel offset from the
> others, perhaps by (guessing again!):
>
>  sox -V2 --no-clobber threech.wav delay 0 0 2t voicedelayed.wav 
>
> For an experiment, it's worth making the delay substantial, for example the
> two second value (2t) here.  It'll be easy to tell if that worked.  Later you
> can try different values to get the audio aligned where you need it to be.
>
> (Also note that there's an effect named 'silence' that can be used to chop
> unwanted 'silent' or at least quieter than the wanted sound audio out of a
> track, so a different approach that might help would be to make sure that
> none of the tracks have much silence at the start, before you merge them.)
>
> Note that so far, none of the three channels have had their relative volumes
> changed.
>
> To do that, and create a stereo file from the three, you'd need to use the
> remix effect.


I did:

 $ sox -M piano.wav voice.wav voicedelayed.wav delay 0.3 0.3 0

to delay piano of 0.3 seconds (`delay' at the end of the command line), and

 $ sox voicedelayed.wav final_result.wav remix -m 1p-5,3p-5 2p+5,3p-5

to decrease the volume of the left channel of piano of 5db, increase the volume
of the right channel of piano of 5db and decrease voice's volume of 5db.  It
seems to be working fine.  Thanks.  Then I'll be using sox instead of Audacity
to manipulate recorded tracks...


>> One more thing: I remember, Jeremy, your suggestion of purchasing a
>> multi-channel audio interface, to be preferred to a mixer, and will do in
>> future.  But do you think that the solution I'm adopting for now: different
>> files on different single-channel audio cards and then merging them - dou
>> you think this is a good solution as well...?  What difference between this
>> cheap one and more or less expensive multi channel interface...?
>
> Your current solution is the cheapest I can think of, and no doubt you'll
> learn quite a lot doing this.


The reason why I'm starting with that cheap solution is not only its cheapness
but that I first want to learn with it, and also because it suits my basic
needs for now.

Thanks,

Regards,

Rodolfo

Re: [solved] Re: Live recording

[Jeremy Nicoll]

On Thu, 17 Aug 2017, at 08:57, Rodolfo Medina wrote:
> Jeremy Nicoll  writes:

> > You do realise that merging files, adjusting balance etc are all possible
> > with sox?
> >
> > One reason I do that sort of thing with sox is that by keeping note of the
> > commands I used to do each stage, I automatically document how I manipulated
> > a set of audio files.  Documenting anything done via a GUI as in Audacity is
> > a great deal more difficult.
> >
> > It's worth documenting what you do so that if necessary you can exactly 
> > repeat the process at a later date.
> 
> 
> Thanks...  In fact, what you suggest is exactly what I wanted to do but
> didn't
> manage to...  In fact, suppose I have two files: piano.wav and voice.wav,
> created by sox in recording piano and voice respectively, simultaneously.
> piano.wav is a stereo file, with the two channels, left and right, inside
> it;
> whereas voice.wav is a monophonic file.  When I put them together to
> create the
> final, say, result.wav, I must properly allign them.  Now, Audacity makes
> this
> job easy thanks to the graphical possibility of seeing the waving forms
> and
> magnifying them.  Instead, with sox, I tried to use the `delay' option
> with no
> success.  Maybe can you suggest a better and proper way to do that...?

I've never tried that.  The sox mail list is a good place to ask for sox
help.

One thing I'd suggest (since sox is potentially complicated) is that
instead
of trying to use sox with one command that does everything, you try to
do 
it in stages.  That way you can check that what you get at the end of
each
stage is what you expect.   Sox has effects that will tell you about
what is in 
a file.

 I think first I'd check simply that I could create a file containing
 all three 
channels, eg by: 

 sox -V2 --no-clobber -M piano.wav voice.wav threech.wav  

The -V2 sets a fairly high level of verbosity; you might need -V3
 
The --no-clobber prevents sox from overwriting a file.  It's easy to get
a command
wrong and accidentally destroy an original file; personally I work on
copies of files
AND use --no-clobber.

-M tells sox to merge the files.  You should end up with a 3 channel
file, with the piano
audio on channels 1 and 2 and voice on 3.


If that works (and ironically, Audacity might be an easy way to make
sure) I think 
I'd next try to make a file with the voice channel offset from the
others, perhaps 
by  (guessing again!):

 sox -V2 --no-clobber threech.wav delay 0 0 2t voicedelayed.wav 

For an experiment, it's worth making the delay substantial, for example
the two 
second value (2t) here.  It'll be easy to tell if that worked.  Later
you can try different
values to get the audio aligned where you need it to be.

(Also note that there's an effect named 'silence' that can be used to
chop unwanted
'silent' or at least quieter than the wanted sound audio out of a track,
so a different 
approach that might help would be to make sure that none of the tracks
have much 
silence at the start, before you merge them.) 

Note that so far, none of the three channels have had their relative
volumes changed.

To do that, and create a stereo file from the three, you'd need to use
the  remix  effect.



 
> One more thing: I remember, Jeremy, your suggestion of purchasing a
> multi-channel audio interface, to be preferred to a mixer, and will do in
> future.  But do you think that the solution I'm adopting for now:
> different
> files on different single-channel audio cards and then merging them - dou
> you
> think this is a good solution as well...?  What difference between this
> cheap
> one and more or less expensive multi channel interface...?

Your current solution is the cheapest I can think of, and no doubt
you'll learn quite a
lot doing this.  I'm afraid I've no idea about what's currently
available in cheap audio 
interfaces.  Reading buyer reviews in eg Amazon is a good way of finding
out what can 
and cannot be done with equipment though.

More expensive interfaces will be sold on the assumption that people
using them are
using higher quality equipment, eg decent microphones.  As price and
quality of mics
increase you expect to get things like: mics that add little (or barely
audible) noise to a 
recording; mics that are more accurate, mics that can better cope with
both quiet and 
loud sounds...

Such mics though typically need 'phantom power'.  They'd probably be on
'balanced' 
audio cables (so 2 wires plus earth/screen per mic), and possibly XLR
connectors...  
There comes a point where the box you plug the mics into needs to be
designed for 
that.

Then, the signal that comes from a mic is (especially with very
sensitive mics) very 
small.  It needs to be amplified - which is what microphone
pre-amplifiers do.  Cheap
mic pre-amps tend to add noise or ruin the sound from a decent mic... 

After that, the amplified sound from each mic needs to be converted from
an analogue
signal to digital.  Better 

Re: [solved] Re: Live recording

[Rodolfo Medina]

Jeremy Nicoll  writes:

> On Thu, 17 Aug 2017, at 01:37, Rodolfo Medina wrote:
>
>> Thanks...  But for my present needs, it seems that sox and audacity are
>> sufficient: with sox I record tracks from multiple audio cards into
>> different files; then with Audacity I merge those tracks into one final
>> file, and have the possibility of adjusting at pleasure the balancing
>> between left and right channel for each track and also adjust the relative
>> volumes.  In my litte basic experiments, I don't note any minimum effect due
>> to time drifting or so, about which I read...
>
> You do realise that merging files, adjusting balance etc are all possible
> with sox?
>
> One reason I do that sort of thing with sox is that by keeping note of the
> commands I used to do each stage, I automatically document how I manipulated
> a set of audio files.  Documenting anything done via a GUI as in Audacity is
> a great deal more difficult.
>
> It's worth documenting what you do so that if necessary you can exactly 
> repeat the process at a later date.


Thanks...  In fact, what you suggest is exactly what I wanted to do but didn't
manage to...  In fact, suppose I have two files: piano.wav and voice.wav,
created by sox in recording piano and voice respectively, simultaneously.
piano.wav is a stereo file, with the two channels, left and right, inside it;
whereas voice.wav is a monophonic file.  When I put them together to create the
final, say, result.wav, I must properly allign them.  Now, Audacity makes this
job easy thanks to the graphical possibility of seeing the waving forms and
magnifying them.  Instead, with sox, I tried to use the `delay' option with no
success.  Maybe can you suggest a better and proper way to do that...?

One more thing: I remember, Jeremy, your suggestion of purchasing a
multi-channel audio interface, to be preferred to a mixer, and will do in
future.  But do you think that the solution I'm adopting for now: different
files on different single-channel audio cards and then merging them - dou you
think this is a good solution as well...?  What difference between this cheap
one and more or less expensive multi channel interface...?

Thanks,

Rodolfo

Re: [solved] Re: Live recording

[Jeremy Nicoll]

On Thu, 17 Aug 2017, at 01:37, Rodolfo Medina wrote:

> Thanks...  But for my present needs, it seems that sox and audacity are
> sufficient: with sox I record tracks from multiple audio cards into
> different
> files; then with Audacity I merge those tracks into one final file, and
> have
> the possibility of adjusting at pleasure the balancing between left and
> right
> channel for each track and also adjust the relative volumes.  In my litte
> basic
> experiments, I don't note any minimum effect due to time drifting or so,
> about
> which I read...

You do realise that merging files, adjusting balance etc are all
possible with 
sox?  

One reason I do that sort of thing with sox is that by keeping note of
the 
commands I used to do each stage, I automatically document how I 
manipulated a set of audio files.  Documenting anything done via a GUI
as
in Audacity is a great deal more difficult.

It's worth documenting what you do so that if necessary you can exactly 
repeat the process at a later date.


-- 
Jeremy Nicoll - my opinions are my own.

Re: [solved] Re: Live recording

[Rodolfo Medina]

Zenaan Harkness  writes:

> If you ever need more flexibility, or more control over latency, or a
> need to adjust individual track offsets ("latency") after the fact,
> post-recording mix down sessions, many types of automation whilst
> recording, and many other high end audio tasks - jackd/Ardour may be
> just the solution you will then be looking for :)
>
> jackd may be built Ardour these days - if so, that would likely make
> config even easier.
>
> [...]
>
> Summary: the best of
> the best is available with jackd and Ardour, for absolutely any
> tricky situation.


Thanks...  But for my present needs, it seems that sox and audacity are
sufficient: with sox I record tracks from multiple audio cards into different
files; then with Audacity I merge those tracks into one final file, and have
the possibility of adjusting at pleasure the balancing between left and right
channel for each track and also adjust the relative volumes.  In my litte basic
experiments, I don't note any minimum effect due to time drifting or so, about
which I read...

Rodolfo

Re: [solved] Re: Live recording

[Zenaan Harkness]

On Wed, Aug 16, 2017 at 11:16:06AM -0400, Ric Moore wrote:
> On 08/16/2017 09:40 AM, Zenaan Harkness wrote:
> please excuse my amateur wording here. Summary: the best of
> > the best is available with jackd and Ardour, for absolutely any
> > tricky situation.
> 
> Doesn't jack require an rt kernel to enable all of it's features?? Ric

That sounds right - I certainly installed the ...-rt kernel, but I
think it just depends on your latency requirements - again from
memory, I tyhink jackd will happily run at "pulse audio" levels of
latency with a simple setting, and thereby audio will be buffered
long enough to not need an -rt kernel.

Re: [solved] Re: Live recording

[Ric Moore]

On 08/16/2017 09:40 AM, Zenaan Harkness wrote:
please excuse my amateur wording here. Summary: the best of

the best is available with jackd and Ardour, for absolutely any
tricky situation.


Doesn't jack require an rt kernel to enable all of it's features?? Ric


--
My father, Victor Moore (Vic) used to say:
"There are two Great Sins in the world...
..the Sin of Ignorance, and the Sin of Stupidity.
Only the former may be overcome." R.I.P. Dad.
http://linuxcounter.net/user/44256.html

Re: [solved] Re: Live recording

[Zenaan Harkness]

On Wed, Aug 16, 2017 at 01:42:18PM +0200, Rodolfo Medina wrote:
> Zenaan Harkness  writes:
> 
> > On Wed, Aug 16, 2017 at 03:03:46AM +0200, Rodolfo Medina wrote:
> >> Apparently, Audacity doesn't let you record simultaneously from two or more
> >> sources...  you have to choose one source.
> >
> > Ardour should only take half a day to start using - it absolutely
> > rocks - high end DAW FTW :D
> 
> 
> Thanks...  As far as I see, Ardour and Jack are powerful tools...  On the 
> other
> hand, with the above recording procedure, i.e. several simultaneous sessions 
> of
> sox, no drifting or latency effects did I appreciate at all...  So it is maybe
> worth for me to continue that way till the moment such problems will arise...

Indeed - if it aint broke as they say :)

Glad to hear you have achieved your desired recording result.

If you ever need more flexibility, or more control over latency, or a
need to adjust individual track offsets ("latency") after the fact,
post-recording mix down sessions, many types of automation whilst
recording, and many other high end audio tasks - jackd/Ardour may be
just the solution you will then be looking for :)

jackd may be built Ardour these days - if so, that would likely make
config even easier.

One little nugget in the back of my mind from a few years ago when I
was last multi-tracking, is a jackd plugin with high quality "audio
anti aliasing" (not sure the proper term sorry) in real time, to mix
input sources which are delivering different sample rates, AND
different skew rates, with respect to each other - basically a full
software "time lock" function WITH high end sample rate anti
aliasing. I didn't need it, but it looked like it would allow
seamless "real time latency/skew correction" of basic mobo line-in
tracks, with tracks coming from hardware with proper time sync
codes... please excuse my amateur wording here. Summary: the best of
the best is available with jackd and Ardour, for absolutely any
tricky situation.

Have fun :)

Re: [solved] Re: Live recording

[Rodolfo Medina]

Zenaan Harkness  writes:

> On Wed, Aug 16, 2017 at 03:03:46AM +0200, Rodolfo Medina wrote:
>> Rodolfo Medina  writes:
>> 
>> > deloptes  writes:
>> >
>> >>> 
>> >>> For human voice, I bought a USB audio card and plugged a third
>> >>> microphone into it.  So now I have:
>> >>> 
>> >>>  mic1 for piano basses; |__ plugged together into the
>> >>>  mic2 for piano highs;  |   above Y cable
>> >>>  mic3 for voice -> -> -> -> plugged into the USB dongle.
>> >>> 
>> >>> Then I do:
>> >>> 
>> >>>  $ sox -t alsa default piano.wav
>> >>> 
>> >>> and, at the same time, on another xterm session,
>> >>> 
>> >>>  $ sox -t alsa wh:2,0 voice.wav
>> >>> 
>> >>> where wh:2,0 is the USB device (do: `arecord -l' first).  This way I get
>> >>> two audio files: piano.wav and voice.wav.  The first one is stereo and
>> >>> the second is mono.  In the end I merge the two together with Audacity.
>> >>> By default, Audacity puts the mono file just in the middle between left
>> >>> and right channel; but, if you like, you can have it weight more left or
>> >>> more right, in the percentage you want.  I must say that the result is
>> >>> acceptable, and more...
>> >>> 
>> >> Why not do all that directly in Audacity? I am sure it works and it will
>> >> take care of the timing automatically
>> >
>> >
>> > Thanks, I'll have a try.
>> 
>> 
>> Apparently, Audacity doesn't let you record simultaneously from two or more
>> sources...  you have to choose one source.
>
> Ardour should only take half a day to start using - it absolutely
> rocks - high end DAW FTW :D


Thanks...  As far as I see, Ardour and Jack are powerful tools...  On the other
hand, with the above recording procedure, i.e. several simultaneous sessions of
sox, no drifting or latency effects did I appreciate at all...  So it is maybe
worth for me to continue that way till the moment such problems will arise...

Rodolfo

Re: [solved] Re: Live recording

[Zenaan Harkness]

On Wed, Aug 16, 2017 at 03:03:46AM +0200, Rodolfo Medina wrote:
> Rodolfo Medina  writes:
> 
> > deloptes  writes:
> >
> >>> 
> >>> For human voice, I bought a USB audio card and plugged a third microphone
> >>> into it.  So now I have:
> >>> 
> >>>  mic1 for piano basses; |__ plugged together into the
> >>>  mic2 for piano highs;  |   above Y cable
> >>>  mic3 for voice -> -> -> -> plugged into the USB dongle.
> >>> 
> >>> Then I do:
> >>> 
> >>>  $ sox -t alsa default piano.wav
> >>> 
> >>> and, at the same time, on another xterm session,
> >>> 
> >>>  $ sox -t alsa wh:2,0 voice.wav
> >>> 
> >>> where wh:2,0 is the USB device (do: `arecord -l' first).  This way I get
> >>> two audio files: piano.wav and voice.wav.  The first one is stereo and the
> >>> second is mono.  In the end I merge the two together with Audacity.  By
> >>> default, Audacity puts the mono file just in the middle between left and
> >>> right channel; but, if you like, you can have it weight more left or more
> >>> right, in the percentage you want.  I must say that the result is
> >>> acceptable, and more...
> >>> 
> >> Why not do all that directly in Audacity? I am sure it works and it will
> >> take care of the timing automatically
> >
> >
> > Thanks, I'll have a try.
> 
> 
> Apparently, Audacity doesn't let you record simultaneously from two or more
> sources...  you have to choose one source.

Ardour should only take half a day to start using - it absolutely
rocks - high end DAW FTW :D

Re: [solved] Re: Live recording

[Rodolfo Medina]

Rodolfo Medina  writes:

> deloptes  writes:
>
>>> 
>>> For human voice, I bought a USB audio card and plugged a third microphone
>>> into it.  So now I have:
>>> 
>>>  mic1 for piano basses; |__ plugged together into the
>>>  mic2 for piano highs;  |   above Y cable
>>>  mic3 for voice -> -> -> -> plugged into the USB dongle.
>>> 
>>> Then I do:
>>> 
>>>  $ sox -t alsa default piano.wav
>>> 
>>> and, at the same time, on another xterm session,
>>> 
>>>  $ sox -t alsa wh:2,0 voice.wav
>>> 
>>> where wh:2,0 is the USB device (do: `arecord -l' first).  This way I get
>>> two audio files: piano.wav and voice.wav.  The first one is stereo and the
>>> second is mono.  In the end I merge the two together with Audacity.  By
>>> default, Audacity puts the mono file just in the middle between left and
>>> right channel; but, if you like, you can have it weight more left or more
>>> right, in the percentage you want.  I must say that the result is
>>> acceptable, and more...
>>> 
>> Why not do all that directly in Audacity? I am sure it works and it will
>> take care of the timing automatically
>
>
> Thanks, I'll have a try.


Apparently, Audacity doesn't let you record simultaneously from two or more
sources...  you have to choose one source.

Rodolfo

Re: [solved] Re: Live recording

[deloptes]

> 
> 
> Thanks, I'll have a try.  But can we say that all this allows us to do
> without
> mixer or multi-channel audio interface...?  In fact, I suppose I could
> even add some other USB cards if I wanted to add more instruments, say a
> violin...
> 
> Cheers,
> 
> Rodolfo

there are always some physical limitations, so it depends on your computer,
if it is usb3, how the usb are implemented etc.

you can always try

regards

Re: [solved] Re: Live recording

[Rodolfo Medina]

deloptes  writes:

>> 
>> For human voice, I bought a USB audio card and plugged a third microphone
>> into
>> it.  So now I have:
>> 
>>  mic1 for piano basses; |__ plugged together into the
>>  mic2 for piano highs;  |   above Y cable
>>  mic3 for voice -> -> -> -> plugged into the USB dongle.
>> 
>> Then I do:
>> 
>>  $ sox -t alsa default piano.wav
>> 
>> and, at the same time, on another xterm session,
>> 
>>  $ sox -t alsa wh:2,0 voice.wav
>> 
>> where wh:2,0 is the USB device (do: `arecord -l' first).  This way I get
>> two
>> audio files: piano.wav and voice.wav.  The first one is stereo and the
>> second
>> is mono.  In the end I merge the two together with Audacity.  By default,
>> Audacity puts the mono file just in the middle between left and right
>> channel; but, if you like, you can have it weight more left or more right,
>> in the
>> percentage you want.  I must say that the result is acceptable, and
>> more...
>> 
> Why not do all that directly in Audacity? I am sure it works and it will
> take care of the timing automatically


Thanks, I'll have a try.  But can we say that all this allows us to do without
mixer or multi-channel audio interface...?  In fact, I suppose I could even add
some other USB cards if I wanted to add more instruments, say a violin...

Cheers,

Rodolfo

Re: [solved] Re: Live recording

[deloptes]

> 
> For human voice, I bought a USB audio card and plugged a third microphone
> into
> it.  So now I have:
> 
>  mic1 for piano basses; |__ plugged together into the
>  mic2 for piano highs;  |   above Y cable
>  mic3 for voice -> -> -> -> plugged into the USB dongle.
> 
> Then I do:
> 
>  $ sox -t alsa default piano.wav
> 
> and, at the same time, on another xterm session,
> 
>  $ sox -t alsa wh:2,0 voice.wav
> 
> where wh:2,0 is the USB device (do: `arecord -l' first).  This way I get
> two
> audio files: piano.wav and voice.wav.  The first one is stereo and the
> second
> is mono.  In the end I merge the two together with Audacity.  By default,
> Audacity puts the mono file just in the middle between left and right
> channel; but, if you like, you can have it weight more left or more right,
> in the
> percentage you want.  I must say that the result is acceptable, and
> more...
> 
Why not do all that directly in Audacity? I am sure it works and it will
take care of the timing automatically

regards

Re: [solved] Re: Live recording

[Rodolfo Medina]

Rodolfo Medina  writes:

> Rodolfo Medina  writes:
>
>> According to:
>>
>>  http://www.upubuntu.com/2013/05/how-to-record-your-voice-from.html
>>
>> I record live sound via microphone just doing:
>>
>>  $ sox -t alsa default output.wav
>>
>> Now I was wondering about the stereo o non-stereo character of such a home
>> made recording...  I tried to use two microphones together, plugging them
>> together into the PC with a small common connection doubber.  Can we say the
>> result is stereo...?  I would doubt...  and how to have - if possible - a
>> stereo effect with the above basic recording instruments?
>
>
>
>
> Thanks to all.  The problem seems to be solved with such a cable:
>
>  https://www.thomann.de/at/pro_snake_78219_yadapterkabel.htm

Well, actually better this one:

 http://hosatech.com/product/ymm-261/

> as suggested by deloptes and other listers.  The cable consists in two female
> 3.5mm terminations, each of them mono, and a male 3.5mm stereo.  One mic at
> one female end, the other one at the other female end, and the male end
> plugged into the microphone input of my netbook.  All this seems to produce a
> perfect stereo effect: the two channels sound to be very well separated.
>
> I'll be using the above simple connection system to live piano recording: mic
> 1 on the basses (left), mic 2 on the high (right).
>
> My next step is trying to add human voice, say in the middle.  I'll see if
> this is possible by slightly complicating the above solution, without preamp
> or mixer or multi-channel audio interface.  I'll be posting here if the
> attempt succeeds.


For human voice, I bought a USB audio card and plugged a third microphone into
it.  So now I have:

 mic1 for piano basses; |__ plugged together into the
 mic2 for piano highs;  |   above Y cable
 mic3 for voice -> -> -> -> plugged into the USB dongle.

Then I do:

 $ sox -t alsa default piano.wav

and, at the same time, on another xterm session,

 $ sox -t alsa wh:2,0 voice.wav

where wh:2,0 is the USB device (do: `arecord -l' first).  This way I get two
audio files: piano.wav and voice.wav.  The first one is stereo and the second
is mono.  In the end I merge the two together with Audacity.  By default,
Audacity puts the mono file just in the middle between left and right channel;
but, if you like, you can have it weight more left or more right, in the
percentage you want.  I must say that the result is acceptable, and more...

Thanks,

Rodolfo

Re: Live recording

[Rodolfo Medina]

Jeremy Nicoll  writes:

> On Mon, 7 Aug 2017, at 23:41, Rodolfo Medina wrote:
>
>> Fascinating...!  But now I got very interested in the multi channel audio
>> interface you suggest...  Before looking for one to buy, I'd like to
>> better
>> know and understand how it works...  
>
> They're just boxes which can have more than two mics (or line-level signals
> eg from instruments) plugged into them.  Inside there's multiple analogue-
> to-digital converters.  The digital data from all of these is then sent along
> the USB connection to the computer.  Some interfaces might send all the
> channels so they arrive in a single file on the computer, which then contains
> multiple separate channels, others may directly generate separate files on
> the computer.
>
> It's unimportant which you get because a file containing multiple channels
> can be split into separate files (with eg sox), or a set of files can be
> combined (with eg sox).
>
>
> I can't advise you on what to buy...  because I suspect you're going to spend
> a great deal less than I did when I last bought one...  That was a Tascam
> box:
>
> http://tascam.com/product/us-2000/
>
> which you'll see can handle 16 separate inputs at once...  There's a more
> recent version of that these days...  A box like that is aimed at people used
> to using professional audio equipment.


Your explanation is just what I was looking for...  Very simple and clear.
Here:

 
https://stackoverflow.com/questions/14950823/sox-exe-mixing-mono-vocals-with-stereo-music

it is shown how to operate with sox the way you said.


> There will be lower-spec interfaces around too, but you obviously need to
> find one that's known to work with linux.  You also probably don't want one
> with eg XLR sockets for mics.


Yes, as far as I understand this is probably the main problem: find something
that works with Linux...

Thanks indeed,

Cheers,

Rodolfo

Re: Live recording

[Jeremy Nicoll]

On Mon, 7 Aug 2017, at 23:41, Rodolfo Medina wrote:

> Fascinating...!  But now I got very interested in the multi channel audio
> interface you suggest...  Before looking for one to buy, I'd like to
> better
> know and understand how it works...  

They're just boxes which can have more than two mics (or line-level
signals
eg from instruments) plugged into them.  Inside there's multiple
analogue-
to-digital converters.  The digital data from all of these is then sent
along 
the USB connection to the computer.  Some interfaces might send all the 
channels so they arrive in a single file on the computer, which then
contains
multiple separate channels, others may directly generate separate files
on 
the computer.

It's unimportant which you get because a file containing multiple
channels
can be split into separate files (with eg sox), or a set of files can be
combined
(with eg sox).


I can't advise you on what to buy...  because I suspect you're going to
spend a
great deal less than I did when I last bought one...   That was a Tascam
box:

http://tascam.com/product/us-2000/

which you'll see can handle 16 separate inputs at once...  There's a
more recent 
version of that these days...   A box like that is aimed at people used
to using 
professional audio equipment.  

There will be lower-spec interfaces around too, but you obviously need
to find 
one that's known to work with linux.  You also probably don't want one
with 
eg XLR sockets for mics.

-- 
Jeremy Nicoll - my opinions are my own.

Re: Live recording

[David Christensen]

On 08/07/17 16:13, David Christensen wrote:

On 08/07/17 00:18, Rodolfo Medina wrote:

I started with one microphone: I bought an external USB audio card and
plugged
into the USB port of my computer.  Then I plugged the microphone into
the `mic'
input of the card and started Audacity.  From the main menu, I
selected the
`USB PnP Sound Device' as recording device, pressed the red button,
spoke into
the mic but no sound is recorded: not even the usual wave forms are
shown.
Neither with socks nor arecord can I record my voice from that USB
card.  Any
idea...?


Audacity is doing what you told it to do -- record from the USB audio
interface device.  Plug your microphone into that.


My bad -- I mis-read your post and thought you plugged the microphone 
into your laptop.



What is the make and model of your USB audio interface?


Does it have Linux support?


Does the device appear under whatever audio mixer applet you have on 
your desktop?  Is it unmuted?  Is the gain turned up?



David

Re: Live recording

[David Christensen]

On 08/07/17 00:18, Rodolfo Medina wrote:

I started with one microphone: I bought an external USB audio card and plugged
into the USB port of my computer.  Then I plugged the microphone into the `mic'
input of the card and started Audacity.  From the main menu, I selected the
`USB PnP Sound Device' as recording device, pressed the red button, spoke into
the mic but no sound is recorded: not even the usual wave forms are shown.
Neither with socks nor arecord can I record my voice from that USB card.  Any
idea...?


Audacity is doing what you told it to do -- record from the USB audio 
interface device.  Plug your microphone into that.



It looks like Audacity can record all the input channels from one 
device, but not multiple channels from multiple devices (e.g. built-in 
sound card plus USB audio interface):


http://wiki.audacityteam.org/index.php?title=Multichannel%5FRecording


David

Re: Live recording

[Rodolfo Medina]

David Wright  writes:

> On Mon 07 Aug 2017 at 19:56:34 (+0200), Rodolfo Medina wrote:
>> Jeremy Nicoll  writes:
>> 
>> > On Sun, 6 Aug 2017, at 21:09, Rodolfo Medina wrote:
>> >
>> >> M...  Otherwise I'll have to buy a mixer.
>> >> 
>> >> Rodolfo
>> >
>> > If you can capture multiple channels' audio and have them in separate
>> > files on your computer then you can mix them using sox.  You don't have to
>> > have a physical mixer.
>> 
>> 
>> Yes, but I was referring to the time delay problem that has been arised by
>> some
>> listers...
>
> That was me, and we had moved on to multiple PCs, whereas now we're
> back to talking about one PC with multiple channels.
>
> Back to two PCs, it did occur to me that if you mix your L/R from the
> piano onto one channel of the final mix and use the singer's mic in
> the other, you might get fewer artificial effects, particularly with
> speakers because the room contributes plenty of muddling.

Well, no, I tought of: left channel on piano bass, right channel onto piano
high notes and voice, say, somewhere in the middle...


> Way back in 1958, the BBC tried experimenting with stereo broadcasts
> on Saturday mornings using TV for one channel and the Third Programme
> (radio) for the other. Naturally there was a lot of strolling around
> the studio at their end and fighting over the hot seat at our end. But
> without any other experience of stereo sound (in the true "solid"
> sense of the word), it's difficult for me to recall how well the
> effect was transferred to our living room. Nor do I know how similar
> the signal processing timing was between a cheap, inherited, Band I TV
> and a state of the art Leak Trough-Line Band II tuner. With TV chassis
> floating at mains potential, there was not much thought of mixing the
> channels or tape recording them.


Fascinating...!  But now I got very interested in the multi channel audio
interface you suggest...  Before looking for one to buy, I'd like to better
know and understand how it works...  For example in the case of piano (two mono
mics) and voice (1 mic, say mono as well)...

Cheers,
Rodolfo

Re: Live recording

[David Wright]

On Mon 07 Aug 2017 at 19:56:34 (+0200), Rodolfo Medina wrote:
> Jeremy Nicoll  writes:
> 
> > On Sun, 6 Aug 2017, at 21:09, Rodolfo Medina wrote:
> >
> >> M...  Otherwise I'll have to buy a mixer.
> >> 
> >> Rodolfo
> >
> > If you can capture multiple channels' audio and have them in separate files
> > on your computer then you can mix them using sox.  You don't have to have a
> > physical mixer.
> 
> 
> Yes, but I was referring to the time delay problem that has been arised by 
> some
> listers...

That was me, and we had moved on to multiple PCs, whereas now we're
back to talking about one PC with multiple channels.

Back to two PCs, it did occur to me that if you mix your L/R from the
piano onto one channel of the final mix and use the singer's mic in
the other, you might get fewer artificial effects, particularly with
speakers because the room contributes plenty of muddling.

Way back in 1958, the BBC tried experimenting with stereo broadcasts
on Saturday mornings using TV for one channel and the Third Programme
(radio) for the other. Naturally there was a lot of strolling around
the studio at their end and fighting over the hot seat at our end. But
without any other experience of stereo sound (in the true "solid"
sense of the word), it's difficult for me to recall how well the
effect was transferred to our living room. Nor do I know how similar
the signal processing timing was between a cheap, inherited, Band I TV
and a state of the art Leak Trough-Line Band II tuner. With TV chassis
floating at mains potential, there was not much thought of mixing the
channels or tape recording them.

Cheers,
David.

Re: [solved] Re: Live recording

[Rodolfo Medina]

Jeremy Nicoll  writes:

> On Sun, 6 Aug 2017, at 17:18, Rodolfo Medina wrote:
>
>> To add a third microphone for human voice (the former two are for piano),
>> I plan to use a second PC as suggested by Fungi4All.  This way I'll
>> continue to do without mixer or audio interface, till the moment I'll want 
>> to do things more professionally.  Now, they're just home made records...
>
> The single best reason for using a multi-channel (ie not just a stereo) audio
> interface is simplicity.  All the channels will be in-sync with each other
> and all the audio signals can be captured on a single computer.


...within different files...?

Thanks,

Rodolfo

Re: Live recording

[Rodolfo Medina]

Jeremy Nicoll  writes:

> On Sun, 6 Aug 2017, at 21:09, Rodolfo Medina wrote:
>
>> M...  Otherwise I'll have to buy a mixer.
>> 
>> Rodolfo
>
> If you can capture multiple channels' audio and have them in separate files
> on your computer then you can mix them using sox.  You don't have to have a
> physical mixer.


Yes, but I was referring to the time delay problem that has been arised by some
listers...

Rodolfo

Re: [solved] Re: Live recording

[Jeremy Nicoll]

On Sun, 6 Aug 2017, at 17:18, Rodolfo Medina wrote:

> To add a third microphone for human voice (the former two are for piano),
> I plan to use a second PC as suggested by Fungi4All.  This way I'll
> continue to do without mixer or audio interface, till the moment I'll want 
> to do things more professionally.  Now, they're just home made records...

The single best reason for using a multi-channel (ie not just a stereo)
audio 
interface is simplicity.  All the channels will be in-sync with each
other and 
all the audio signals can be captured on a single computer.

-- 
Jeremy Nicoll - my opinions are my own.

Re: Live recording

[Jeremy Nicoll]

On Sun, 6 Aug 2017, at 21:09, Rodolfo Medina wrote:

> M...  Otherwise I'll have to buy a mixer.
> 
> Rodolfo

If you can capture multiple channels' audio and have them in separate
files
on your computer then you can mix them using  sox.   You don't have to
have 
a physical mixer.

-- 
Jeremy Nicoll - my opinions are my own.

Re: Live recording

[Rodolfo Medina]

deloptes  writes:

> Rodolfo Medina wrote:
>
>> Please, could you explain that?  Suppose I have two usb audio cards, one
>> for each microphone.  Will they be plugged together into the usb port of
>> the PC?
>
> It might be also PCI card but you said you have a notebook.
> You plug them to the pc and you get two separate mic inputs. Now use some
> utility like jack (I haven't played with it for years) or something else to
> assign the inputs to L/R line in or perhaps Audacity offers a mapping of
> input to output as well.
>
> Consider the data volume - perhaps USB 3 will give you better results.


I started with one microphone: I bought an external USB audio card and plugged
into the USB port of my computer.  Then I plugged the microphone into the `mic'
input of the card and started Audacity.  From the main menu, I selected the
`USB PnP Sound Device' as recording device, pressed the red button, spoke into
the mic but no sound is recorded: not even the usual wave forms are shown.
Neither with socks nor arecord can I record my voice from that USB card.  Any
idea...?

Thanks,

Rodolfo

Re: [solved] Re: Live recording

[Rodolfo Medina]

David Christensen  writes:

> On 08/06/17 09:18, Rodolfo Medina wrote:
>> The cable that made me possible to live record stereo from two mics, without
>> mixer nor preamp nor external audio card nor audio interface, is a 3.5mm
>> twin-mono-female and a 3.5mm single-stereo-male: the two mics plugged into
>> the two mono females and the stereo male plugged into the `mic' input of my
>> PC.  This cable was solded for me by the owner of the electricity shop near
>> my house.
>
> That is called a stereo break-out cable:
>
> http://hosatech.com/product/ymm-261/
>
>
>> To add a third microphone for human voice (the former two are for piano), I
>> plan to use a second PC as suggested by Fungi4All.  This way I'll continue
>> to do without mixer or audio interface, till the moment I'll want to do
>> things more professionally.  Now, they're just home made records...
>
> As I understand it, professional digital audio recording gear includes clock
> in and clock out connectors.  All the devices are linked together with
> cables, one device serves as the master clock, and all the other devices are
> slaves.
>
>
> Without hardware clock synchronization, the clocks for the various recording
> devices will drift ("clock skew") and the recordings will lose time
> alignment.  One work-around is to record audible synchronizing marks near the
> beginning of a take and near the end -- e.g. strike two sticks together, clap
> your hands, use a "clicker" device, etc..  Then during editing/ mix-down, use
> digital audio workstation software with time-stretch/ time-compression/
> time-alignment features to adjust the individual recordings until all the
> synchronizing marks line up exactly.


It seems that Audacity can do that...

Rodolfo

Re: [solved] Re: Live recording

[David Christensen]

On 08/06/17 09:18, Rodolfo Medina wrote:

The cable that made me possible to live record stereo from two mics, without
mixer nor preamp nor external audio card nor audio interface, is a 3.5mm
twin-mono-female and a 3.5mm single-stereo-male: the two mics plugged into the
two mono females and the stereo male plugged into the `mic' input of my PC.
This cable was solded for me by the owner of the electricity shop near my
house.


That is called a stereo break-out cable:

http://hosatech.com/product/ymm-261/



To add a third microphone for human voice (the former two are for piano), I
plan to use a second PC as suggested by Fungi4All.  This way I'll continue to
do without mixer or audio interface, till the moment I'll want to do things
more professionally.  Now, they're just home made records...


As I understand it, professional digital audio recording gear includes 
clock in and clock out connectors.  All the devices are linked together 
with cables, one device serves as the master clock, and all the other 
devices are slaves.



Without hardware clock synchronization, the clocks for the various 
recording devices will drift ("clock skew") and the recordings will lose 
time alignment.  One work-around is to record audible synchronizing 
marks near the beginning of a take and near the end -- e.g. strike two 
sticks together, clap your hands, use a "clicker" device, etc..  Then 
during editing/ mix-down, use digital audio workstation software with 
time-stretch/ time-compression/ time-alignment features to adjust the 
individual recordings until all the synchronizing marks line up exactly.



David

Re: Live recording

[Rodolfo Medina]

David Wright  writes:

> On Sun 06 Aug 2017 at 20:21:49 (+0200), Rodolfo Medina wrote:
>> David Wright  writes:
>> > On Sun 06 Aug 2017 at 18:18:46 (+0200), Rodolfo Medina wrote:
>> >> The cable that made me possible to live record stereo from two mics,
>> >> without mixer nor preamp nor external audio card nor audio interface, is
>> >> a 3.5mm twin-mono-female and a 3.5mm single-stereo-male: the two mics
>> >> plugged into the two mono females and the stereo male plugged into the
>> >> `mic' input of my PC.  This cable was solded for me by the owner of the
>> >> electricity shop near my house.
>> >
>> > Glad you got one. (My Y cables are for sharing a single stereo output
>> > into two people's headsets.) The soldering solution I proposed earlier
>> > was specifically to avoid having to deal with soldering tiny wires into
>> > tiny plugs, practical in the past but no fun nowadays.
>> >
>> >> To add a third microphone for human voice (the former two are for piano),
>> >> I plan to use a second PC as suggested by Fungi4All.  This way I'll
>> >> continue to do without mixer or audio interface, till the moment I'll
>> >> want to do things more professionally.  Now, they're just home made
>> >> records...
>> >
>> > Oh my, thoughts of Itchycoo Park come to mind. (Just showing my age.)
>> > I don't think you'll enjoy listening to the results..
>> 
>> 
>> Why do you think so?  Just recording with two mics in the Y cable you spoke
>> about produced a not bad result...
>
> I'm assuming that your vocalist is being accompanied live (otherwise
> the problem disappears by using a second pass) and is being
> accompanied by said piano.


Exactly.


> So both PCs' recordings will have piano on them.

Yes.



> How do you mix than so that the phase of the piano signals is
> preserved? It's not clear to me (but might be worth an experiment)
> that you could avoid phasing effects or localisation (precedence effect)
> instability. However, if it works, so be it. Give it a try. Perhaps
> you can synchronise the recordings by minimising these very effects.


M...  Otherwise I'll have to buy a mixer.

Rodolfo

Re: Live recording

[David Wright]

On Sun 06 Aug 2017 at 20:21:49 (+0200), Rodolfo Medina wrote:
> David Wright  writes:
> > On Sun 06 Aug 2017 at 18:18:46 (+0200), Rodolfo Medina wrote:
> >> The cable that made me possible to live record stereo from two mics, 
> >> without
> >> mixer nor preamp nor external audio card nor audio interface, is a 3.5mm
> >> twin-mono-female and a 3.5mm single-stereo-male: the two mics plugged into
> >> the two mono females and the stereo male plugged into the `mic' input of my
> >> PC.  This cable was solded for me by the owner of the electricity shop near
> >> my house.
> >
> > Glad you got one. (My Y cables are for sharing a single stereo output
> > into two people's headsets.) The soldering solution I proposed earlier
> > was specifically to avoid having to deal with soldering tiny wires into
> > tiny plugs, practical in the past but no fun nowadays.
> >
> >> To add a third microphone for human voice (the former two are for piano), I
> >> plan to use a second PC as suggested by Fungi4All.  This way I'll continue
> >> to do without mixer or audio interface, till the moment I'll want to do
> >> things more professionally.  Now, they're just home made records...
> >
> > Oh my, thoughts of Itchycoo Park come to mind. (Just showing my age.)
> > I don't think you'll enjoy listening to the results..
> 
> 
> Why do you think so?  Just recording with two mics in the Y cable you spoke
> about produced a not bad result...

I'm assuming that your vocalist is being accompanied live (otherwise
the problem disappears by using a second pass) and is being
accompanied by said piano. So both PCs' recordings will have piano on
them. How do you mix than so that the phase of the piano signals is
preserved? It's not clear to me (but might be worth an experiment)
that you could avoid phasing effects or localisation (precedence effect)
instability. However, if it works, so be it. Give it a try. Perhaps
you can synchronise the recordings by minimising these very effects.

Cheers,
David.

Re: Live recording

[Rodolfo Medina]

David Wright  writes:

> On Sun 06 Aug 2017 at 18:18:46 (+0200), Rodolfo Medina wrote:
>> Richard Hector  writes:
>> 
>> > On 05/08/17 03:56, Rodolfo Medina wrote:
>> >> Thanks to all.  The problem seems to be solved with such a cable:
>> >> 
>> >>  https://www.thomann.de/at/pro_snake_78219_yadapterkabel.htm
>> >
>> > Except that it's hard to tell what size those connectors are. Unless
>> > there's something in the description that I can't read that says they're
>> > 3.5mm, they look to me more like 6.25mm. I'm not sure what it is - I
>> > think 3.5mm plugs are usually more rounded on the end, while the larger
>> > ones often have that point. Also, it looks like the case comes apart,
>> > and I think the only ones I've seen with such skinny bodies are moulded
>> > plastic. If that's 3.5mm, I think it would be very hard to assemble by
>> > hand, which the body designs suggest.
>> 
>> 
>> The cable that made me possible to live record stereo from two mics, without
>> mixer nor preamp nor external audio card nor audio interface, is a 3.5mm
>> twin-mono-female and a 3.5mm single-stereo-male: the two mics plugged into
>> the two mono females and the stereo male plugged into the `mic' input of my
>> PC.  This cable was solded for me by the owner of the electricity shop near
>> my house.
>
> Glad you got one. (My Y cables are for sharing a single stereo output
> into two people's headsets.) The soldering solution I proposed earlier
> was specifically to avoid having to deal with soldering tiny wires into
> tiny plugs, practical in the past but no fun nowadays.
>
>> To add a third microphone for human voice (the former two are for piano), I
>> plan to use a second PC as suggested by Fungi4All.  This way I'll continue
>> to do without mixer or audio interface, till the moment I'll want to do
>> things more professionally.  Now, they're just home made records...
>
> Oh my, thoughts of Itchycoo Park come to mind. (Just showing my age.)
> I don't think you'll enjoy listening to the results..


Why do you think so?  Just recording with two mics in the Y cable you spoke
about produced a not bad result...

Rodolfo

Re: Live recording

[David Wright]

On Sun 06 Aug 2017 at 18:18:46 (+0200), Rodolfo Medina wrote:
> Richard Hector  writes:
> 
> > On 05/08/17 03:56, Rodolfo Medina wrote:
> >> Thanks to all.  The problem seems to be solved with such a cable:
> >> 
> >>  https://www.thomann.de/at/pro_snake_78219_yadapterkabel.htm
> >
> > Except that it's hard to tell what size those connectors are. Unless
> > there's something in the description that I can't read that says they're
> > 3.5mm, they look to me more like 6.25mm. I'm not sure what it is - I
> > think 3.5mm plugs are usually more rounded on the end, while the larger
> > ones often have that point. Also, it looks like the case comes apart,
> > and I think the only ones I've seen with such skinny bodies are moulded
> > plastic. If that's 3.5mm, I think it would be very hard to assemble by
> > hand, which the body designs suggest.
> 
> 
> The cable that made me possible to live record stereo from two mics, without
> mixer nor preamp nor external audio card nor audio interface, is a 3.5mm
> twin-mono-female and a 3.5mm single-stereo-male: the two mics plugged into the
> two mono females and the stereo male plugged into the `mic' input of my PC.
> This cable was solded for me by the owner of the electricity shop near my
> house.

Glad you got one. (My Y cables are for sharing a single stereo output
into two people's headsets.) The soldering solution I proposed earlier
was specifically to avoid having to deal with soldering tiny wires into
tiny plugs, practical in the past but no fun nowadays.

> To add a third microphone for human voice (the former two are for piano), I
> plan to use a second PC as suggested by Fungi4All.  This way I'll continue to
> do without mixer or audio interface, till the moment I'll want to do things
> more professionally.  Now, they're just home made records...

Oh my, thoughts of Itchycoo Park come to mind. (Just showing my age.)
I don't think you'll enjoy listening to the results..

Cheers,
David.

Re: Live recording

[Rodolfo Medina]

David Christensen  writes:

> On 08/04/17 00:06, Rodolfo Medina wrote:
>> David Christensen  writes:
>>> What is the make and model of your netbook?
>>
>> It's an Acer Aspire One, and the model should be ZG8.
>
> When I go to the Acer support page:
>
> https://www.acer.com/ac/en/US/content/drivers
>
>
> "ZG8" is not a valid model number -- it should be something like "AO521".
>
>
> If your netbook has a stereo microphone/ line-in connector, then you might be
> able to make stereo recordings by patching the left microphone to the tip (+)
> and sleeve (-) and the right microphone to the ring (+) and sleeve
> (-). (e.g. the negatives are commoned).


Yes, everything lets us think that the `mic' entry of my Acer Aspire One is
stereo: as reported in my messages marked with `solved' in the present thread,
I managed to do stereo live records with the use of a 3.5mm
twin-mono-female--single-stereo-male cable plugged into the `mic' input of my
PC with the two microphones plugged into it.

Thanks,

Rodolfo

Re: [solved] Re: Live recording

[Rodolfo Medina]

Richard Hector  writes:

> On 05/08/17 03:56, Rodolfo Medina wrote:
>> Thanks to all.  The problem seems to be solved with such a cable:
>> 
>>  https://www.thomann.de/at/pro_snake_78219_yadapterkabel.htm
>
> Except that it's hard to tell what size those connectors are. Unless
> there's something in the description that I can't read that says they're
> 3.5mm, they look to me more like 6.25mm. I'm not sure what it is - I
> think 3.5mm plugs are usually more rounded on the end, while the larger
> ones often have that point. Also, it looks like the case comes apart,
> and I think the only ones I've seen with such skinny bodies are moulded
> plastic. If that's 3.5mm, I think it would be very hard to assemble by
> hand, which the body designs suggest.


The cable that made me possible to live record stereo from two mics, without
mixer nor preamp nor external audio card nor audio interface, is a 3.5mm
twin-mono-female and a 3.5mm single-stereo-male: the two mics plugged into the
two mono females and the stereo male plugged into the `mic' input of my PC.
This cable was solded for me by the owner of the electricity shop near my
house.

To add a third microphone for human voice (the former two are for piano), I
plan to use a second PC as suggested by Fungi4All.  This way I'll continue to
do without mixer or audio interface, till the moment I'll want to do things
more professionally.  Now, they're just home made records...

Rodolfo

Re: Live recording

[Curt]

On 2017-08-06, Glenn English  wrote:
> On Sat, Aug 5, 2017 at 9:43 AM, Curt  wrote:
>
>> My understanding is that a stereo microphone is comprised of two
>> microphones in a single unit. That's pretty black and white.\
>
> There was discussion of whether there is such a thing. And I
> considered two mics in one device is kinda half way between one and
> two. Grey :-)
>
>> Why you would use such a device rather than recording with two discrete
>> microphones in an X-Y, ORTF, or MS (et al) configuration (but I read
>> there are single, MS recording units) I dunno.
>
> I use my C-24 because of the mind boggling sound that comes out of it.
> And I can pretty easily just hang it from the ceiling in the middle of
> a concert hall and get an outstanding recording.
>
> Should have said 'used' instead  of 'use'. I got out of the recording
> business when digital audio came along, and became a computer geek --
> computers are as much fun as tape recorders...
>
> MS is trouble because of the transformer(s) used to decipher the
> cardioid/bidirectional mic patterns.

As a total novice I was intrigued by the MS method's post-recording
adjustability. For recording someone singing while accompanying himself
at the acoustic piano I suppose you would need at least three
microphones. Laying down the piano track first would probably present
less difficulties.

It's complicated.  That's why they call them sound *engineers*, I guess.

> Jeremy's post explains all this pretty well.

Yes. 

> --
> Glenn English
>
>


-- 
“Certitude is not the test of certainty.”
--Oliver Wendell Holmes, Jr.

Re: [solved] Re: Live recording

[Joe]

On Sun, 6 Aug 2017 15:37:15 +1200
Richard Hector  wrote:

> On 06/08/17 13:18, Eike Lantzsch wrote:
> > On Sunday, 6 August 2017 11:31:29 -04 Richard Hector wrote:  
> >> On 05/08/17 03:56, Rodolfo Medina wrote:  
> >>> Thanks to all.  The problem seems to be solved with such a cable:
> >>>  https://www.thomann.de/at/pro_snake_78219_yadapterkabel.htm  
> >> Except that it's hard to tell what size those connectors are.
> >> Unless there's something in the description that I can't read that
> >> says they're 3.5mm, they look to me more like 6.25mm. I'm not sure
> >> what it is - I think 3.5mm plugs are usually more rounded on the
> >> end, while the larger ones often have that point. Also, it looks
> >> like the case comes apart, and I think the only ones I've seen
> >> with such skinny bodies are moulded plastic. If that's 3.5mm, I
> >> think it would be very hard to assemble by hand, which the body
> >> designs suggest.
> >>
> >> Richard  
> > 3.5mm and 2.5mm plugs can be soldered all right but  
> 
> Yes - I was trying to suggest that the plugs in the picture, if it's a
> 3.5mm plug, look a bit small in the body to be user-assembled - yet
> they clearly come apart. The ones I've soldered have bigger bodies
> relative to the actual connector. The really thin ones tend to be
> moulded.
> 
> I'm not sure if I'm making myself clear ... it would help if the site
> actually specified what they're selling :-)
> 

Yes, but I think the real issue in making one is that the plug is a
right-angle one, and right-angled plugs are usually pigs to fit. But
they are certainly 1/4" in the picture, the proportions are different
for the miniature versions.

No problem getting 2.5mm and 3.5mm mono or stereo rewireable plugs:
https://www.maplin.co.uk/p/35mm-metal-stereo-plug-fj99h
https://www.maplin.co.uk/p/25mm-plastic-stereo-plug-fj85g

though as another poster said, they need fairly lightweight cable.

-- 
Joe

Re: [solved] Re: Live recording

[Richard Hector]

On 06/08/17 13:18, Eike Lantzsch wrote:
> On Sunday, 6 August 2017 11:31:29 -04 Richard Hector wrote:
>> On 05/08/17 03:56, Rodolfo Medina wrote:
>>> Thanks to all.  The problem seems to be solved with such a cable:
>>>  https://www.thomann.de/at/pro_snake_78219_yadapterkabel.htm
>> Except that it's hard to tell what size those connectors are. Unless
>> there's something in the description that I can't read that says they're
>> 3.5mm, they look to me more like 6.25mm. I'm not sure what it is - I
>> think 3.5mm plugs are usually more rounded on the end, while the larger
>> ones often have that point. Also, it looks like the case comes apart,
>> and I think the only ones I've seen with such skinny bodies are moulded
>> plastic. If that's 3.5mm, I think it would be very hard to assemble by
>> hand, which the body designs suggest.
>>
>> Richard
> 3.5mm and 2.5mm plugs can be soldered all right but

Yes - I was trying to suggest that the plugs in the picture, if it's a
3.5mm plug, look a bit small in the body to be user-assembled - yet they
clearly come apart. The ones I've soldered have bigger bodies relative
to the actual connector. The really thin ones tend to be moulded.

I'm not sure if I'm making myself clear ... it would help if the site
actually specified what they're selling :-)

Richard

Re: [solved] Re: Live recording

[Doug]

On 08/05/2017 08:11 PM, Eike Lantzsch wrote:

On Sunday, 6 August 2017 11:31:29 -04 Richard Hector wrote:

On 05/08/17 03:56, Rodolfo Medina wrote:

Thanks to all.  The problem seems to be solved with such a cable:
  https://www.thomann.de/at/pro_snake_78219_yadapterkabel.htm

That's 1/4" ~ 6.35mm
Stereo on one end and 2 x mono on the other end
but both 6.35mm


Except that it's hard to tell what size those connectors are. Unless
there's something in the description that I can't read that says they're
3.5mm, they look to me more like 6.25mm. I'm not sure what it is - I
think 3.5mm plugs are usually more rounded on the end, while the larger
ones often have that point. Also, it looks like the case comes apart,
and I think the only ones I've seen with such skinny bodies are moulded
plastic. If that's 3.5mm, I think it would be very hard to assemble by
hand, which the body designs suggest.

Richard


I have put together a number of 3.5mm connectors, which you used to be 
able to
get in Radio Shack. I confess that they were not stereo. Also put 
together the
power connectors for 5V and 12V. It's a little hairy, and you need a 
soldering
iron with a fine tip, a good light, and probably magnifying 
lenses--which I have.


--doug

Re: Live recording

[Glenn English]

On Sat, Aug 5, 2017 at 9:43 AM, Curt  wrote:

> My understanding is that a stereo microphone is comprised of two
> microphones in a single unit. That's pretty black and white.\

There was discussion of whether there is such a thing. And I
considered two mics in one device is kinda half way between one and
two. Grey :-)

> Why you would use such a device rather than recording with two discrete
> microphones in an X-Y, ORTF, or MS (et al) configuration (but I read
> there are single, MS recording units) I dunno.

I use my C-24 because of the mind boggling sound that comes out of it.
And I can pretty easily just hang it from the ceiling in the middle of
a concert hall and get an outstanding recording.

Should have said 'used' instead  of 'use'. I got out of the recording
business when digital audio came along, and became a computer geek --
computers are as much fun as tape recorders...

MS is trouble because of the transformer(s) used to decipher the
cardioid/bidirectional mic patterns.

Jeremy's post explains all this pretty well.

--
Glenn English

Re: [solved] Re: Live recording

[Eike Lantzsch]

On Sunday, 6 August 2017 11:31:29 -04 Richard Hector wrote:
> On 05/08/17 03:56, Rodolfo Medina wrote:
> > Thanks to all.  The problem seems to be solved with such a cable:
> >  https://www.thomann.de/at/pro_snake_78219_yadapterkabel.htm
> 
> Except that it's hard to tell what size those connectors are. Unless
> there's something in the description that I can't read that says they're
> 3.5mm, they look to me more like 6.25mm. I'm not sure what it is - I
> think 3.5mm plugs are usually more rounded on the end, while the larger
> ones often have that point. Also, it looks like the case comes apart,
> and I think the only ones I've seen with such skinny bodies are moulded
> plastic. If that's 3.5mm, I think it would be very hard to assemble by
> hand, which the body designs suggest.
> 
> Richard

here's a good write-up of phone connectors of all kind
https://en.wikipedia.org/wiki/Phone_connector_(audio)

Re: [solved] Re: Live recording

[Eike Lantzsch]

On Sunday, 6 August 2017 11:31:29 -04 Richard Hector wrote:
> On 05/08/17 03:56, Rodolfo Medina wrote:
> > Thanks to all.  The problem seems to be solved with such a cable:
> >  https://www.thomann.de/at/pro_snake_78219_yadapterkabel.htm
> 
> Except that it's hard to tell what size those connectors are. Unless
> there's something in the description that I can't read that says they're
> 3.5mm, they look to me more like 6.25mm. I'm not sure what it is - I
> think 3.5mm plugs are usually more rounded on the end, while the larger
> ones often have that point. Also, it looks like the case comes apart,
> and I think the only ones I've seen with such skinny bodies are moulded
> plastic. If that's 3.5mm, I think it would be very hard to assemble by
> hand, which the body designs suggest.
> 
> Richard

3.5mm and 2.5mm plugs can be soldered all right but the problem mostly is to 
purchase the really fine cable with two inner conductors, both shielded.
Common "Stereo Shielded Cable" is commonly too fat and its use always results 
in ugly and unwieldy kludges.
Sometimes I resorted to reusing the cables of old earphone sets, which I had 
otherwise no use for anymore.

Cheers
Eike

Re: [solved] Re: Live recording

[Eike Lantzsch]

On Sunday, 6 August 2017 11:31:29 -04 Richard Hector wrote:
> On 05/08/17 03:56, Rodolfo Medina wrote:
> > Thanks to all.  The problem seems to be solved with such a cable:
> >  https://www.thomann.de/at/pro_snake_78219_yadapterkabel.htm
> 
That's 1/4" ~ 6.35mm
Stereo on one end and 2 x mono on the other end
but both 6.35mm

> Except that it's hard to tell what size those connectors are. Unless
> there's something in the description that I can't read that says they're
> 3.5mm, they look to me more like 6.25mm. I'm not sure what it is - I
> think 3.5mm plugs are usually more rounded on the end, while the larger
> ones often have that point. Also, it looks like the case comes apart,
> and I think the only ones I've seen with such skinny bodies are moulded
> plastic. If that's 3.5mm, I think it would be very hard to assemble by
> hand, which the body designs suggest.
> 
> Richard

Re: [solved] Re: Live recording

[Richard Hector]

On 05/08/17 03:56, Rodolfo Medina wrote:
> Thanks to all.  The problem seems to be solved with such a cable:
> 
>  https://www.thomann.de/at/pro_snake_78219_yadapterkabel.htm

Except that it's hard to tell what size those connectors are. Unless
there's something in the description that I can't read that says they're
3.5mm, they look to me more like 6.25mm. I'm not sure what it is - I
think 3.5mm plugs are usually more rounded on the end, while the larger
ones often have that point. Also, it looks like the case comes apart,
and I think the only ones I've seen with such skinny bodies are moulded
plastic. If that's 3.5mm, I think it would be very hard to assemble by
hand, which the body designs suggest.

Richard

Re: Live recording

[David Christensen]

On 08/04/17 00:06, Rodolfo Medina wrote:

David Christensen  writes:

One more question that might explain the ring -- do the
microphones have switches?


They don't.  The two ones that come with headsets have volume control
wheel, but I don't know if it is for the headsets only.


My first guess would be that the volume control is a stereo logarithmic 
potentiometer wired between the earpieces plug and the earpieces. 
Electronic test equipment might provide more clues.



On 08/04/17 00:06, Rodolfo Medina wrote:

David Christensen  writes:

What is the make and model of your netbook?


It's an Acer Aspire One, and the model should be ZG8.


When I go to the Acer support page:

https://www.acer.com/ac/en/US/content/drivers


"ZG8" is not a valid model number -- it should be something like "AO521".


If your netbook has a stereo microphone/ line-in connector, then you 
might be able to make stereo recordings by patching the left microphone 
to the tip (+) and sleeve (-) and the right microphone to the ring (+) 
and sleeve (-). (e.g. the negatives are commoned).




Do the headsets have one or two phone plugs?  What color or
colors? What size or sizes -- original 1/4 inch, miniature 3.5 mm,
or sub-miniature 2.5 mm?


They all have one green 3.5mm stereo plug.


So, one green stereo 3.5 mm miniature phone plug for the earpieces and 
one black stereo 3.5 mm miniature phone plug for the microphone?



As you know the make and model, perhaps you can find the specifications
and/or contact technical support to ask them what signals are connected 
to the tip, ring, and sleeve.



I have a Logitech headset that came with a Logitech webcam.  Neither
have an obvious model or part number on them.   The headset has:

- One black stereo 3.5 mm miniature phone plug with a headphone symbol

- One pink stereo 3.5 mm miniature phone plug with a microphone symbol.


Checking the DC resistances between the tip, ring, and sleeve of the 
microphone plug using my Fluke 77 DMM:


tip-ring0.3 Ohm
tip-sleeve  1080 Ohm
ring-sleeve 1079 Ohm

I expect that the headset microphone is monophonic, the signal common
is wired to the plug sleeve, and the signal hot is wired to the plug tip
and ring in parallel.


Checking the DC resistances of the earpieces plug:

tip-ring46.1 Ohm
tip-sleeve  23.8 Ohm
ring-sleeve 24.3 Ohm

using some jumper cables, and playing some music on my computer, I 
expect that the two earpieces are monophonic, the earpiece negative 
terminals are wired to the plug sleeve, the left earpiece positive 
terminal is wired to the plug tip, and the right earpiece positive 
terminal is wired to the plug ring.




What size are the phone plugs on the non-headset microphones?


Same: 3.5mm, stereo.  All of them.


Color?


David

Re: Live recording

[Nicolas George]

L'octidi 18 thermidor, an CCXXV, Rodolfo Medina a écrit :
> Please, could you explain that?  Suppose I have two usb audio cards, one for
> each microphone.  Will they be plugged together into the usb port of the PC?

You would need a hammer. Better plug them in two different USB ports.

But that may not work correctly. Two different audio controllers will
have clocks running at slightly different speed. It may not be much, but
it accumulates over time. IIRC (I did the test once) the difference
could be 10^-4. That may sound like not much, but after half an hour of
recording that makes a tenth of second difference, and that is way
beyond unacceptable for your use.

Regards,

-- 
  Nicolas George


signature.asc
Description: Digital signature

Re: Live recording

[deloptes]

Rodolfo Medina wrote:

> Please, could you explain that?  Suppose I have two usb audio cards, one
> for each microphone.  Will they be plugged together into the usb port of
> the PC?

It might be also PCI card but you said you have a notebook.
You plug them to the pc and you get two separate mic inputs. Now use some
utility like jack (I haven't played with it for years) or something else to
assign the inputs to L/R line in or perhaps Audacity offers a mapping of
input to output as well.

Consider the data volume - perhaps USB 3 will give you better results.

regards

Re: Live recording

[Jeremy Nicoll]

On Sat, 5 Aug 2017, at 10:43, Curt wrote:

> My understanding is that a stereo microphone is comprised of two
> microphones in a single unit. That's pretty black and white.

Yes.  You also get units with more than 2 capsules in them.

 
> Why you would use such a device rather than recording with two discrete
> microphones in an X-Y, ORTF, or MS (et al) configuration (but I read
> there are single, MS recording units) I dunno.

One reason is that it's sometimes physically easier to mount (or suspend
from 
the ceiling) a single unit than a pair.  It's tricky if suspending mics
to get them 
to point in exactly the right direction; the weight of the mic cables
can drag the
thing away from the alignment you want.  You can't use a floor stand for
mics
if they have to be high above an audience (I've four floor stands that
each put 
mics up to 14 feet above the floor, but they're not usable where
audience seats 
are where the stands would have to be, and public safety precludes use
of such 
things if people can trip over them or walk into them.  They're
eminently useful 
for recording sessions in halls where the public are not present, or eg
for putting 
mics above sections of an orchestra or in front of a choir.)

Another reason is on some of these mics the directional sensitivity of
the two (or
more) capsules is controllable from the box of electronics at the other
end of the 
mic cables.  So you can decide for each mic if you want a tightly
focussed hyper-
cardioid response (if you like, a shotgun mic) or something slightly
directional, or 
figure of 8 (ie responsive to sound from both sides but not in
front/behind), or omni-
directional, or various points inbetween.   Since no-one can put their
ears where
the mic is (if it's eg 60 feet down from the ceiling and 20 feet above
the floor), the
ability to fine tune what the mic(s) are doing remotely saves an awful
lot of time.
Otherwise you'd have to haul the mics up to the ceiling, adjust them,
lower them 
again, listen for a while, and repeat.  (Or lower them to the floor then
raise them 
again ... needing several people to do that and walkie-talkies to
communicate).

These are the sorts of mics you often see high up in the space in a
concert hall 
auditorium.

-- 
Jeremy Nicoll - my opinions are my own.

Re: Live recording

[Curt]

On 2017-08-05, Glenn English  wrote:

> I'm not real sure what you guys are talking about, but the talk of
> stereo microphones leads into a mildly grey area.
>

My understanding is that a stereo microphone is comprised of two
microphones in a single unit. That's pretty black and white.

Why you would use such a device rather than recording with two discrete
microphones in an X-Y, ORTF, or MS (et al) configuration (but I read
there are single, MS recording units) I dunno.

Here are some edifying links:

http://manual.audacityteam.org/man/how_to_connect_your_equipment.html
http://www.shure.eu/support_download/educational_content/microphones-basics/stereo_microphone_techniques
http://www.uaudio.com/blog/mid-side-mic-recording/


-- 
“Certitude is not the test of certainty.”
--Oliver Wendell Holmes, Jr.

Re: Live recording

[Rodolfo Medina]

deloptes  writes:

> You could however go the cheep way and play with multiple usb/pci audio
> cards, jack and free audio software


Please, could you explain that?  Suppose I have two usb audio cards, one for
each microphone.  Will they be plugged together into the usb port of the PC?

Thanks,

Rodolfo

Re: Live recording

[Glenn English]

I'm not real sure what you guys are talking about, but the talk of
stereo microphones leads into a mildly grey area.

There are stereo microphones -- I have one, an AKG C-24. And there are
a few others.

It's a single microphone in that it's a single object, but it's stereo
because there are actually two mics in there. You point the capsules
in different directions. And there are two outputs.

They're used, mostly, for classical orchestral recordings, in the X-Y
stereo technique.

They're rare, but they do exist. FWIW.

https://en.wikipedia.org/wiki/Microphone_practice

--
Glenn English

Re: Live recording

[deloptes]

Rodolfo Medina wrote:

>> Now your mic is a one bucket full of water and you have to pipes (left
>> and right) ... where does the water flow?
> 
> It flows left and right, I suppose...
> 
> 

yes and this one input recorded on (at least) two channels is called mono.
Mono means single btw.
Good based on this conclusion a mic can never be stereo - it is a single
input. You however have (at least) two outputs for boxes to achieve a
stereo effect. No this single input is recorded or played equally to both
outputs, thus also your output is mono.


> 
> Here we seem to have different advices.  It seems that sometimes, laptops
> have one input hole for both mic and line in.  Some of them, as reported
> by other posters, can even switch from one to another function.  Someone
> else suggested a way to check if mic entry is stereo or mono.  Someone,
> like you, states that mic input is certainly mono, but someone else, also
> around Google, seems to state the contrary, i.e. it can be mono or stereo
> depending on the PC.  This is important to me also because I reversed into

This is true and does not contradict to the said before. Indeed there are
combined inputs. I guess it probes if the one channel is shortened and
perhaps internally switches to mono input.
If one referrs a mic as mono perhaps is meant what the jack looks like.


> digital form some old vynils, and did so using the mic input of my
> netbook, that doesn't have a line in.  So I'd need to know if those *.wav
> files so produced are stereo or not, and, in case they aren't, repeat the
> operation on another machine or adding an external sound card to the
> netbook.
> 

This is not good because using a mic you loose quality and you get a mono
input. You can indeed use two mics and put them right infront of the
speakers, so that you avoid inference, but unless you have some exotic
device there should be also a line out, which you can feed to the line in
of the notebook.

> Also here, someone states that there exist stereo and mono microphones...
> 

it must be something new, but everything is possible. I don't know what is
referred by stereo mic. the mic itself, then it should be two mics (two
buckets), but sound spreads everywhere, so how would two exist in one and
not infer - it makes no sense to me unless the jack is referred, but so we
are again to ground 0. The best way to check this is to look at the
jack/plug - how it looks like - if there are 3 contacts [1] would mean that
the (mono) mic is providing two lines L/R (stereo output). However it is
irrelevant - signal is still mono. If it has 2 contacts it would mean it is
mono - good chance that you can record only left or right if recording
device is not smart enough.

> 
> The splitter works regularly when used in listening mode...
> 

This is true - the only uncertainty here is if notebook/computer can handle
the lower impedance of the mic.

1. https://www.amazon.com/3-5mm-Stereo-Jack-Adapter-black/dp/B00142BZSY

[solved] Re: Live recording

[Rodolfo Medina]

Rodolfo Medina  writes:

> According to:
>
>  http://www.upubuntu.com/2013/05/how-to-record-your-voice-from.html
>
> I record live sound via microphone just doing:
>
>  $ sox -t alsa default output.wav
>
> Now I was wondering about the stereo o non-stereo character of such a home
> made recording...  I tried to use two microphones together, plugging them
> together into the PC with a small common connection doubber.  Can we say the
> result is stereo...?  I would doubt...  and how to have - if possible - a
> stereo effect with the above basic recording instruments?


deloptes  writes:

> First of all you need to get basic knowledge of signal and audio processing
>
> One good way to understand things 8especially about electricity is water and
> pipes.
>
> Now your mic is a one bucket full of water and you have to pipes (left and
> right) ... where does the water flow?
>
> Rodolfo Medina wrote:
>
>> 1) the mic input on my PC is stereo.  In fact, it is a laptop, nay a
>> netbook, doesn't have a line in and it is reasonable that its mic input is
>> also a line in;
>> 
>
> there is no stereo mic - keep in mind - one bucket full of water - not two


Doug  writes:

> You can't get something for nothing. If you want stereo, you will have to
> have two mics or a mic with two separate microphone elements aimed in two
> (left and right) directions. Such a device will have a plug with three
> connections on it: left, right, and ground. Your PC will not be able to
> handle such a microphone! You would need a stereo preamplifier to plug that
> mic into, and then you would plug the stereo output of the preamp into the
> LINE IN jack of the PC.
>
> I would hope that this information will settle the question!



Thanks to all.  The problem seems to be solved with such a cable:

 https://www.thomann.de/at/pro_snake_78219_yadapterkabel.htm

as suggested by deloptes and other listers.  The cable consists in two female
3.5mm terminations, each of them mono, and a male 3.5mm stereo.  One mic at one
female end, the other one at the other female end, and the male end plugged
into the microphone input of my netbook.  All this seems to produce a perfect
stereo effect: the two channels sound to be very well separated.

I'll be using the above simple connection system to live piano recording: mic 1
on the basses (left), mic 2 on the high (right).

My next step is trying to add human voice, say in the middle.  I'll see if this
is possible by slightly complicating the above solution, without preamp or
mixer or multi-channel audio interface.  I'll be posting here if the attempt
succeeds.

Thanks again,

Rodolfo
<

Re: Live recording

[Curt]

On 2017-08-04, Rodolfo Medina  wrote:
>
> Here we seem to have different advices.  It seems that sometimes, laptops have
> one input hole for both mic and line in.  Some of them, as reported by other
> posters, can even switch from one to another function.  Someone else suggested
> a way to check *if* mic entry is stereo or mono.  Someone, like you, states
> that mic input is certainly mono, but someone else, also around Google, seems
> to state the contrary, i.e. it can be mono or stereo depending on the PC.  
> This
> is important to me also because I reversed into digital form some old vynils,
> and did so using the mic input of my netbook, that doesn't have a line in.  So
> I'd need to know if those *.wav files so produced are stereo or not, and, in
> case they aren't, repeat the operation on another machine or adding an 
> external
> sound card to the netbook.


Can't you tell whether the wavs are stereo or not by listening to them?

In a mixer program like aumix (curses), for example, channels which are
"stereo-capable" (sic) will have balance controls (makes sense). So that
might be a roundabout way (opening up the old mixer, don't you know) to
reassure yourself concerning your mic (or bum yourself completely out after
having converted the entire pianistic *oeuvre* of Chopin from vinyl to
digital *mono*, depending).

But if you are unable discern the difference by listening forget it and be 
happy.

-- 
“Certitude is not the test of certainty.”
--Oliver Wendell Holmes, Jr.

Re: Live recording

[Jeremy Nicoll]

On Fri, 4 Aug 2017, at 00:22, deloptes wrote:

> > 3) mic2 is stereo.

> now way - such thing does not exist - one can not be two ..

Wrong.  Such things do exist.  But they're aimed at professional users.
For example, a relatively cheap thing:

http://www.coutant.org/m22rp/

(this single body has 2 elements in it recording what's known as M+S - 
Middle & Side - where there's a front-facing microphone as well as a
figure-of-8 response thing recording what's happening on each side of 
the microphone.  It can't be plugged in to a normal pair of mixer inputs
without some trickery (or in this particular model, use of the 'matrix'
box it comes with).


And something less cheap (if you can find one at all these days):
http://www.proaudioeurope.com/info/classic-catalogue/akg-microphones/akg-c422-microphone


Then there are single-body mics with multiple capsules, eg this:
http://www.soundfield.com/

(four capsules; this mic gets plugged into a controller box and - if you
buy the most expensive
version you can adjust the width, depth & even height (for surround
sound)  of stereo image 
produced from it.  It is VERY expensive - many thousands of pounds.)

-- 
Jeremy Nicoll - my opinions are my own.

Re: Live recording

[Rodolfo Medina]

deloptes  writes:

> First of all you need to get basic knowledge of signal and audio processing
>
> One good way to understand things 8especially about electricity is water and
> pipes.
>
> Now your mic is a one bucket full of water and you have to pipes (left and
> right) ... where does the water flow?

It flows left and right, I suppose...


> Rodolfo Medina wrote:
>
>> With my two microphones, say mic1 and mic2, I did a little experiment: I
>> recorded my voice with mic1, using sox, then listened to the so created
>> .wav file and the sound was heard only on the left channel.  Instead,
>> doing the same with mic2, the sound was heard on both channels.  How
>> should we conclude?  It seems to me that we should conclude that:
>> 
>> 1) the mic input on my PC is stereo.  In fact, it is a laptop, nay a
>> netbook, doesn't have a line in and it is reasonable that its mic input is
>> also a line in;
>> 
>
> there is no stereo mic - keep in mind - one bucket full of water - not two

Here we seem to have different advices.  It seems that sometimes, laptops have
one input hole for both mic and line in.  Some of them, as reported by other
posters, can even switch from one to another function.  Someone else suggested
a way to check *if* mic entry is stereo or mono.  Someone, like you, states
that mic input is certainly mono, but someone else, also around Google, seems
to state the contrary, i.e. it can be mono or stereo depending on the PC.  This
is important to me also because I reversed into digital form some old vynils,
and did so using the mic input of my netbook, that doesn't have a line in.  So
I'd need to know if those *.wav files so produced are stereo or not, and, in
case they aren't, repeat the operation on another machine or adding an external
sound card to the netbook.


>> 2) mic1 is mono;
>> 
>> 3) mic2 is stereo.
>> 
>
> now way - such thing does not exist - one can not be two ... even easier ...
> you have two ears and one mouth ... so you hear stereo, but you speak mono

Also here, someone states that there exist stereo and mono microphones...


>> Do you agree?  But then, if it is so, my rough home made live piano
>> record, done using mic1 and mic2 plugged together in a
>> one-male--two-female splitter, is actually stereo...?
>> 
>
> it really depends how this splitter is wired. What I post you before is what
> you need - a splitter that splits the stereo L/R to a single L and single
> R.

Yes, this is clear.


> Stereo jack has 3 contacts mass and L,R while mono has 2. So I conclude
> something is wrong with your wiring. That's it.

The splitter works regularly when used in listening mode...


> get a propper splitter and try the line in


Thanks,

Rodolfo

Re: Live recording

[Rodolfo Medina]

David Christensen  writes:

> On 08/03/17 05:23, Rodolfo Medina wrote:
>> The mic input on my PC [may be] stereo.  In fact, it is a laptop, nay a
>> netbook, doesn't have a line in and it is reasonable that its mic
>> input is also a line in;
>
> What is the make and model of your netbook?

It's an Acer Aspire One, and the model should be ZG8.


> My Dell Inspiron E1505 laptop has a stereo microphone connector.  When I run
> an OS with good sound support, the audio mixer applet includes a means
> (e.g. checkbox) for selecting between microphone or line-level signals.
>
>
> On 08/03/17 11:15, Rodolfo Medina wrote:
>> Jeremy Nicoll  writes:
>>>
>>> Look at: https://i.ytimg.com/vi/x1q9MXvjDlM/maxresdefault.jpg
>>
>> All four my mics, all my headphones, all my adaptors, are all of type
>> 2 in the picture, where it says `stereo'.
>
>
> On 08/03/17 06:19, Rodolfo Medina wrote:
>> Jeremy Nicoll  writes:
>>>
>>> What makes and models are your mics?
>>
>> I can't tell, because they're old and I don't keep their specs.  One
>> of them was given to me about 15 years ago, the other I don't even
>> remember how I have it.  But I've got another teo: they are, each of
>> them, part of a headphone. They also let hear the recorded sound from
>> both channels. They are:
>>
>> http://www.trust.com/it/product/11916-primo-chat-headset
>>
>> and
>>
>> http://www.trust.com/it/product/20685-mauro-headset
>
> Do the headsets have one or two phone plugs?  What color or colors? What size
> or sizes -- original 1/4 inch, miniature 3.5 mm, or sub-miniature 2.5 mm?

They all have one green 3.5mm stereo plug.

> https://en.wikipedia.org/wiki/Phone_connector_(audio)#Modern_connectors
>
>
> What size are the phone plugs on the non-headset microphones?

Same: 3.5mm, stereo.  All of them.

Thanks!

Rodolfo

Re: Live recording

[Rodolfo Medina]

David Christensen  writes:

> On 08/03/17 06:19, Rodolfo Medina wrote:
>> Jeremy Nicoll  writes:
>>>
>>> What makes and models are your mics?
>>
>> I can't tell, because they're old and I don't keep their specs.  One
>> of them was given to me about 15 years ago, the other I don't even
>> remember how I have it.
>
> One more question that might explain the ring -- do the microphones have
> switches?


They don't.  The two ones that come with headsets have volume control wheel,
but I don't know if it is for the headsets only.

Rodolfo

Re: Live recording

[David Christensen]

On 08/03/17 06:19, Rodolfo Medina wrote:

Jeremy Nicoll  writes:


What makes and models are your mics?


I can't tell, because they're old and I don't keep their specs.  One
of them was given to me about 15 years ago, the other I don't even
remember how I have it.


One more question that might explain the ring -- do the microphones have 
switches?



David

Re: Live recording

[David Christensen]

On 08/03/17 05:23, Rodolfo Medina wrote:

The mic input on my PC [may be] stereo.  In fact, it is a laptop, nay a
netbook, doesn't have a line in and it is reasonable that its mic
input is also a line in;


What is the make and model of your netbook?


My Dell Inspiron E1505 laptop has a stereo microphone connector.  When I 
run an OS with good sound support, the audio mixer applet includes a 
means (e.g. checkbox) for selecting between microphone or line-level 
signals.



On 08/03/17 11:15, Rodolfo Medina wrote:

Jeremy Nicoll  writes:


Look at: https://i.ytimg.com/vi/x1q9MXvjDlM/maxresdefault.jpg


All four my mics, all my headphones, all my adaptors, are all of type
2 in the picture, where it says `stereo'.



On 08/03/17 06:19, Rodolfo Medina wrote:

Jeremy Nicoll  writes:


What makes and models are your mics?


I can't tell, because they're old and I don't keep their specs.  One
of them was given to me about 15 years ago, the other I don't even
remember how I have it.  But I've got another teo: they are, each of
them, part of a headphone. They also let hear the recorded sound from
both channels. They are:

http://www.trust.com/it/product/11916-primo-chat-headset

and

http://www.trust.com/it/product/20685-mauro-headset


Do the headsets have one or two phone plugs?  What color or colors? 
What size or sizes -- original 1/4 inch, miniature 3.5 mm, or 
sub-miniature 2.5 mm?


https://en.wikipedia.org/wiki/Phone_connector_(audio)#Modern_connectors


What size are the phone plugs on the non-headset microphones?


David

Re: Live recording

[deloptes]

First of all you need to get basic knowledge of signal and audio processing

One good way to understand things 8especially about electricity is water and
pipes.

Now your mic is a one bucket full of water and you have to pipes (left and
right) ... where does the water flow?

Rodolfo Medina wrote:

> With my two microphones, say mic1 and mic2, I did a little experiment: I
> recorded my voice with mic1, using sox, then listened to the so created
> .wav file and the sound was heard only on the left channel.  Instead,
> doing the same with mic2, the sound was heard on both channels.  How
> should we conclude?  It seems to me that we should conclude that:
> 
> 1) the mic input on my PC is stereo.  In fact, it is a laptop, nay a
> netbook, doesn't have a line in and it is reasonable that its mic input is
> also a line in;
> 

there is no stereo mic - keep in mind - one bucket full of water - not two

> 2) mic1 is mono;
> 
> 3) mic2 is stereo.
> 

now way - such thing does not exist - one can not be two ... even easier ...
you have two ears and one mouth ... so you hear stereo, but you speak mono

> Do you agree?  But then, if it is so, my rough home made live piano
> record, done using mic1 and mic2 plugged together in a
> one-male--two-female splitter, is actually stereo...?
> 

it really depends how this splitter is wired. What I post you before is what
you need - a splitter that splits the stereo L/R to a single L and single
R.

Stereo jack has 3 contacts mass and L,R while mono has 2. So I conclude
something is wrong with your wiring. That's it.

get a propper splitter and try the line in

Re: Live recording

[Rodolfo Medina]

Doug  writes:

> On 08/03/2017 08:19 AM, Rodolfo Medina wrote:
>> Jeremy Nicoll  writes:
>>
>>> On Thu, 3 Aug 2017, at 13:23, Rodolfo Medina wrote:
>>>
 3) mic2 is stereo.
>>> Not necessarily.  It might be a mono signal that's been duplicated across
>>> two outputs.  It's only 2-channel if it can record two separate sounds at
>>> the same time.
>>>
>>> You can get microphones which, in a single unit, record more than one
>>> channel at once.  Their labelling or artwork on them normally makes it
>>> clear that they have L and R (or more than that) inputs.
>>>
>>> What makes and models are your mics?
>>
>> I can't tell, because they're old and I don't keep their specs.  One of them
>> was given to me about 15 years ago, the other I don't even remember how I
>> have it.  But I've got another teo: they are, each of them, part of a
>> headphone.  They also let hear the recorded sound from both channels.  They
>> are:
>>
>>   http://www.trust.com/it/product/11916-primo-chat-headset
>>
>> and
>>
>>   http://www.trust.com/it/product/20685-mauro-headset
>>
>> Rodolfo
>>
>>
> I looked at both of the links. Note that there are two connections for each
> device: headset (earphone) connection and mic connection. The headset
> connection will be
> stereo, and the mic connection will be mono. If there is talkback (i.e., you
> can hear the mic output on the headphones,) the mic sound will appear in both
> earpieces,
> but will not be stereo--it will just be the same sound in both earpieces.
>
> You can't get something for nothing. If you want stereo, you will have to
> have two mics or a mic with two separate microphone elements aimed in two
> (left and right) directions. Such a device will have a plug with three
> connections on it: left, right, and ground. Your PC will not be able to
> handle such a microphone! You would need a stereo preamplifier to plug that
> mic into, and then you would plug the stereo output of the preamp into the
> LINE IN jack of the PC.
>
> I would hope that this information will settle the question!
>
> --doug

why do you get angry...?  there's nothing to get angry, I think...

Re: Live recording

[Doug]

On 08/03/2017 08:19 AM, Rodolfo Medina wrote:

Jeremy Nicoll  writes:


On Thu, 3 Aug 2017, at 13:23, Rodolfo Medina wrote:


3) mic2 is stereo.

Not necessarily.  It might be a mono signal that's been duplicated across two
outputs.  It's only 2-channel if it can record two separate sounds at the
same time.

You can get microphones which, in a single unit, record more than one
channel at once.  Their labelling or artwork on them normally makes it
clear that they have L and R (or more than that) inputs.

What makes and models are your mics?


I can't tell, because they're old and I don't keep their specs.  One of them
was given to me about 15 years ago, the other I don't even remember how I have
it.  But I've got another teo: they are, each of them, part of a headphone.
They also let hear the recorded sound from both channels.  They are:

  http://www.trust.com/it/product/11916-primo-chat-headset

and

  http://www.trust.com/it/product/20685-mauro-headset

Rodolfo


I looked at both of the links. Note that there are two connections for 
each device: headset (earphone) connection and mic connection. The 
headset connection will be
stereo, and the mic connection will be mono. If there is talkback (i.e., 
you can hear the mic output on the headphones,) the mic sound will 
appear in both earpieces,

but will not be stereo--it will just be the same sound in both earpieces.

You can't get something for nothing. If you want stereo, you will have 
to have two mics or a mic with two separate microphone elements aimed in 
two (left and right)
directions. Such a device will have a plug with three connections on it: 
left, right, and ground. Your PC will not be able to handle such a 
microphone! You would need
a stereo preamplifier to plug that mic into, and then you would plug the 
stereo output of the preamp into the LINE IN jack of the PC.


I would hope that this information will settle the question!

--doug

Re: Live recording

[Rodolfo Medina]

Jeremy Nicoll  writes:

> On Thu, 3 Aug 2017, at 16:45, Rodolfo Medina wrote:
>
>> Thanks.  But all my 4 microphones terminates in 3.5mm, and the splitter I
>> was
>> talking about is two 3.5mm female and one 3.5mm male.  Is this you
>> mean...?
>
> No.  Look at: https://i.ytimg.com/vi/x1q9MXvjDlM/maxresdefault.jpg
>
> That should show you pictures of two, three and four contact mini jack
> plugs.
>
> A two-contact one is used for one audio channel (the two contacts being
> signal & ground).
>
> A three contact one is used for two channels (signal 1, signal 2, and
> ground).
>
> A four contact one is for three channels (eg on a stereo headset which
> has L & R speakers, 
> but a single mono microphone) - the four contacts being L, R, mic and
> ground.
>
> (The tip/ring/sleeve terms that someone else mentioned are names for the
> different contacts
> on a three-contact jack plug.) 
>
> Which type of plugs do you have on your mics?

All four my mics, all my headphones, all my adaptors, are all of type 2 in the
picture, where it says `stereo'.

> On 'professional' equipment it gets a bit more complicated when three
> connections are 
> used for a single audio channel, being the +ve half of a waveform, the
> -ve half, and ground.
> (These are known as 'balanced' connections, and typically use either XLR
> plugs & sockets
> or 3-contact 6.25mm audio jacks.)


Many thanks,

Rodolfo

Re: Live recording

[Rodolfo Medina]

David Wright  writes:

> On Thu 03 Aug 2017 at 15:43:15 (+0200), Rodolfo Medina wrote:
>> Rodolfo Medina  writes:
>> 
>> > Jeremy Nicoll  writes:
>> >
>> >> On Thu, 3 Aug 2017, at 13:23, Rodolfo Medina wrote:
>> >>
>> >>> 3) mic2 is stereo.
>> >>
>> >> Not necessarily.  It might be a mono signal that's been duplicated across
>> >> two outputs.
>> 
>> Is there, as far as you know, a mono microphone model that we can be sure it
>> does not do so?  I.e., its sound is heared on only one channel?
>
> Most mono microphones will be fitted with a plug that has a tip and
> barrel, but no ring (between the two). The effects you observe could
> be no more than chance vagarities in the mechanical construction of
> plug and socket.
>
>> >> It's only 2-channel if it can record two separate sounds at the
>> >> same time.
>> >>
>> >> You can get microphones which, in a single unit, record more than one 
>> >> channel at once.  Their labelling or artwork on them normally makes it 
>> >> clear that they have L and R (or more than that) inputs.
>> >>
>> >> What makes and models are your mics?
>> >
>> >
>> > I can't tell, because they're old and I don't keep their specs.  One of
>> > them was given to me about 15 years ago, the other I don't even remember
>> > how I have it.  But I've got another teo: they are, each of them, part of
>> > a headphone.  They also let hear the recorded sound from both channels.
>> > They are:
>> >
>> >  http://www.trust.com/it/product/11916-primo-chat-headset
>> >
>> > and
>> >
>> >  http://www.trust.com/it/product/20685-mauro-headset
>> 
>> 
>> Just now I received a reply from Trust assistence and they say the mic
>> (Primo) is mono.
>> 
>> Anyway, about my example above, can we conclude that mic1 is mono and that
>> the mic input of my PC is stereo...?
>
> If you want to know whether the input is stereo, plug in a cable which
> has a stereo 3.5mm plug going to two phono plugs. (These computer↔monitor
> sound cables were everywhere at one time.) Touch just the pin of each
> phono plug in turn and see if you get mains hum separately on the
> left and right channels of the computer.

I used a cable thath has, at one end, a 3.5mm stereo male plug; and, at the
other end, a couple of twin phono RCA males.  I plugged the 3.5mm into the mic
input of the PC.  Then I did:

 $ sox -t alsa default output.wav

Then I touched alternatively one and the other of the two phone plugs and saw
that the output of sox alternatively filled up the left or right channel.


> If you're keen to use these microphones and you have the budget and
> attitude of a school pupil, buy two mono 3.5mm sockets and a twin
> phono socket unit. Solder the connections yourself using the phone
> socket pair to anchor the 3.5mm ones and give it stability. Then
> connect this device to the computer with the aforementioned cable
> and plug in the mikes.

Not very clear to me...  But I'm not good at soldering...

Many thanks,

Rodolfo

RE: Live recording

[larry owens]

FYI the "tip, ring and sleeve" notation derives from the 3-wire connection that 
connects old land-lines to the telephone central office in the user's  area.
Larry

-Original Message-
From: Jeremy Nicoll [mailto:jn.ml.dbn...@letterboxes.org] 
Sent: Thursday, August 03, 2017 10:07 AM
To: debian-user@lists.debian.org
Subject: Re: Live recording

On Thu, 3 Aug 2017, at 16:45, Rodolfo Medina wrote:

> Thanks.  But all my 4 microphones terminates in 3.5mm, and the splitter I
> was
> talking about is two 3.5mm female and one 3.5mm male.  Is this you
> mean...?

No.  Look at: https://i.ytimg.com/vi/x1q9MXvjDlM/maxresdefault.jpg

That should show you pictures of two, three and four contact mini jack
plugs.

A two-contact one is used for one audio channel (the two contacts being
signal & ground).

A three contact one is used for two channels (signal 1, signal 2, and
ground).

A four contact one is for three channels (eg on a stereo headset which
has L & R speakers, 
but a single mono microphone) - the four contacts being L, R, mic and
ground.

(The tip/ring/sleeve terms that someone else mentioned are names for the
different contacts
on a three-contact jack plug.) 

Which type of plugs do you have on your mics?


On 'professional' equipment it gets a bit more complicated when three
connections are 
used for a single audio channel, being the +ve half of a waveform, the
-ve half, and ground.
(These are known as 'balanced' connections, and typically use either XLR
plugs & sockets
or 3-contact 6.25mm audio jacks.)

-- 
Jeremy Nicoll - my opinions are my own.

Re: Live recording

[Jeremy Nicoll]

On Thu, 3 Aug 2017, at 16:45, Rodolfo Medina wrote:

> Thanks.  But all my 4 microphones terminates in 3.5mm, and the splitter I
> was
> talking about is two 3.5mm female and one 3.5mm male.  Is this you
> mean...?

No.  Look at: https://i.ytimg.com/vi/x1q9MXvjDlM/maxresdefault.jpg

That should show you pictures of two, three and four contact mini jack
plugs.

A two-contact one is used for one audio channel (the two contacts being
signal & ground).

A three contact one is used for two channels (signal 1, signal 2, and
ground).

A four contact one is for three channels (eg on a stereo headset which
has L & R speakers, 
but a single mono microphone) - the four contacts being L, R, mic and
ground.

(The tip/ring/sleeve terms that someone else mentioned are names for the
different contacts
on a three-contact jack plug.) 

Which type of plugs do you have on your mics?


On 'professional' equipment it gets a bit more complicated when three
connections are 
used for a single audio channel, being the +ve half of a waveform, the
-ve half, and ground.
(These are known as 'balanced' connections, and typically use either XLR
plugs & sockets
or 3-contact 6.25mm audio jacks.)

-- 
Jeremy Nicoll - my opinions are my own.

Re: Live recording

[Rodolfo Medina]

David Wright  writes:

> On Thu 03 Aug 2017 at 15:43:15 (+0200), Rodolfo Medina wrote:
>> Rodolfo Medina  writes:
>> 
>> > Jeremy Nicoll  writes:
>> >
>> >> On Thu, 3 Aug 2017, at 13:23, Rodolfo Medina wrote:
>> >>
>> >>> 3) mic2 is stereo.
>> >>
>> >> Not necessarily.  It might be a mono signal that's been duplicated across
>> >> two outputs.
>> 
>> Is there, as far as you know, a mono microphone model that we can be sure it
>> does not do so?  I.e., its sound is heared on only one channel?
>
> Most mono microphones will be fitted with a plug that has a tip and
> barrel, but no ring (between the two). The effects you observe could
> be no more than chance vagarities in the mechanical construction of
> plug and socket.
>
>> >> It's only 2-channel if it can record two separate sounds at the
>> >> same time.
>> >>
>> >> You can get microphones which, in a single unit, record more than one 
>> >> channel at once.  Their labelling or artwork on them normally makes it 
>> >> clear that they have L and R (or more than that) inputs.
>> >>
>> >> What makes and models are your mics?
>> >
>> >
>> > I can't tell, because they're old and I don't keep their specs.  One of
>> > them was given to me about 15 years ago, the other I don't even remember
>> > how I have it.  But I've got another teo: they are, each of them, part of
>> > a headphone.  They also let hear the recorded sound from both channels.
>> > They are:
>> >
>> >  http://www.trust.com/it/product/11916-primo-chat-headset
>> >
>> > and
>> >
>> >  http://www.trust.com/it/product/20685-mauro-headset
>> 
>> 
>> Just now I received a reply from Trust assistence and they say the mic
>> (Primo) is mono.
>> 
>> Anyway, about my example above, can we conclude that mic1 is mono and that
>> the mic input of my PC is stereo...?
>
> If you want to know whether the input is stereo, plug in a cable which
> has a stereo 3.5mm plug going to two phono plugs. (These computer↔monitor
> sound cables were everywhere at one time.) Touch just the pin of each
> phono plug in turn and see if you get mains hum separately on the
> left and right channels of the computer.
>
> If you're keen to use these microphones and you have the budget and
> attitude of a school pupil, buy two mono 3.5mm sockets and a twin
> phono socket unit. Solder the connections yourself using the phone
> socket pair to anchor the 3.5mm ones and give it stability. Then
> connect this device to the computer with the aforementioned cable
> and plug in the mikes.


Thanks.  But all my 4 microphones terminates in 3.5mm, and the splitter I was
talking about is two 3.5mm female and one 3.5mm male.  Is this you mean...?

Rodolfo

Re: Live recording

[David Wright]

On Thu 03 Aug 2017 at 15:43:15 (+0200), Rodolfo Medina wrote:
> Rodolfo Medina  writes:
> 
> > Jeremy Nicoll  writes:
> >
> >> On Thu, 3 Aug 2017, at 13:23, Rodolfo Medina wrote:
> >>
> >>> 3) mic2 is stereo.
> >>
> >> Not necessarily.  It might be a mono signal that's been duplicated across
> >> two outputs.
> 
> Is there, as far as you know, a mono microphone model that we can be sure it
> does not do so?  I.e., its sound is heared on only one channel?

Most mono microphones will be fitted with a plug that has a tip and
barrel, but no ring (between the two). The effects you observe could
be no more than chance vagarities in the mechanical construction of
plug and socket.

> >> It's only 2-channel if it can record two separate sounds at the
> >> same time.
> >>
> >> You can get microphones which, in a single unit, record more than one 
> >> channel at once.  Their labelling or artwork on them normally makes it 
> >> clear that they have L and R (or more than that) inputs.
> >>
> >> What makes and models are your mics?
> >
> >
> > I can't tell, because they're old and I don't keep their specs.  One of them
> > was given to me about 15 years ago, the other I don't even remember how I
> > have it.  But I've got another teo: they are, each of them, part of a
> > headphone.  They also let hear the recorded sound from both channels.  They
> > are:
> >
> >  http://www.trust.com/it/product/11916-primo-chat-headset
> >
> > and
> >
> >  http://www.trust.com/it/product/20685-mauro-headset
> 
> 
> Just now I received a reply from Trust assistence and they say the mic (Primo)
> is mono.
> 
> Anyway, about my example above, can we conclude that mic1 is mono and that the
> mic input of my PC is stereo...?

If you want to know whether the input is stereo, plug in a cable which
has a stereo 3.5mm plug going to two phono plugs. (These computer↔monitor
sound cables were everywhere at one time.) Touch just the pin of each
phono plug in turn and see if you get mains hum separately on the
left and right channels of the computer.

If you're keen to use these microphones and you have the budget and
attitude of a school pupil, buy two mono 3.5mm sockets and a twin
phono socket unit. Solder the connections yourself using the phone
socket pair to anchor the 3.5mm ones and give it stability. Then
connect this device to the computer with the aforementioned cable
and plug in the mikes.

Cheers,
David.

Re: Live recording

[Rodolfo Medina]

Rodolfo Medina  writes:

> Jeremy Nicoll  writes:
>
>> On Thu, 3 Aug 2017, at 13:23, Rodolfo Medina wrote:
>>
>>> 3) mic2 is stereo.
>>
>> Not necessarily.  It might be a mono signal that's been duplicated across
>> two outputs.

Is there, as far as you know, a mono microphone model that we can be sure it
does not do so?  I.e., its sound is heared on only one channel?



>> It's only 2-channel if it can record two separate sounds at the
>> same time.
>>
>> You can get microphones which, in a single unit, record more than one 
>> channel at once.  Their labelling or artwork on them normally makes it 
>> clear that they have L and R (or more than that) inputs.
>>
>> What makes and models are your mics?
>
>
> I can't tell, because they're old and I don't keep their specs.  One of them
> was given to me about 15 years ago, the other I don't even remember how I
> have it.  But I've got another teo: they are, each of them, part of a
> headphone.  They also let hear the recorded sound from both channels.  They
> are:
>
>  http://www.trust.com/it/product/11916-primo-chat-headset
>
> and
>
>  http://www.trust.com/it/product/20685-mauro-headset


Just now I received a reply from Trust assistence and they say the mic (Primo)
is mono.

Anyway, about my example above, can we conclude that mic1 is mono and that the
mic input of my PC is stereo...?

Thanks,

Rodolfo

Re: Live recording

[Rodolfo Medina]

Jeremy Nicoll  writes:

> On Thu, 3 Aug 2017, at 13:23, Rodolfo Medina wrote:
>
>> 3) mic2 is stereo.
>
> Not necessarily.  It might be a mono signal that's been duplicated across two
> outputs.  It's only 2-channel if it can record two separate sounds at the
> same time.
>
> You can get microphones which, in a single unit, record more than one 
> channel at once.  Their labelling or artwork on them normally makes it 
> clear that they have L and R (or more than that) inputs.
>
> What makes and models are your mics?


I can't tell, because they're old and I don't keep their specs.  One of them
was given to me about 15 years ago, the other I don't even remember how I have
it.  But I've got another teo: they are, each of them, part of a headphone.
They also let hear the recorded sound from both channels.  They are:

 http://www.trust.com/it/product/11916-primo-chat-headset

and

 http://www.trust.com/it/product/20685-mauro-headset

Rodolfo

Re: Live recording

[Jeremy Nicoll]

On Thu, 3 Aug 2017, at 13:23, Rodolfo Medina wrote:

> 3) mic2 is stereo.

Not necessarily.  It might be a mono signal that's been duplicated
across 
two outputs.  It's only 2-channel if it can record two separate sounds
at
the same time. 

You can get microphones which, in a single unit, record more than one 
channel at once.  Their labelling or artwork on them normally makes it 
clear that they have L and R (or more than that) inputs.

What makes and models are your mics?

-- 
Jeremy Nicoll - my opinions are my own.

Re: Live recording

[Rodolfo Medina]

deloptes  writes:

> Rodolfo Medina wrote:
>
>> Now I was wondering about the stereo o non-stereo character of such a home
>> made recording...  I tried to use two microphones together, plugging them
>> together into the PC with a small common connection doubber.  Can we say
>> the result is stereo...?  I would doubt...  and how to have - if possible
>> - a stereo effect with the above basic recording instruments?
>
> [...]
>
> The mic is mono, so the input if I am not wrong is mono as well.
>
> [...]
>
> The mic has also different Ohms or perhaps better to say impedance, so I am
> not sure if it would work, but you could try plugging those mics to the
> line in, not the mic.
>
> So line in, is the stereo one. I think if you plugin mic(s) without preamp,
> because of the high Ohms, it would be very silent, but still worth a try.
>
> You need a stereo jack to L-R like this one
> https://www.thomann.de/at/pro_snake_78219_yadapterkabel.htm
>
> This way you'll also know if it is true stereo, because if you unplug the
> one mic, it would record only on the other channel. Of course you can see
> this in audacity or even with arecord


With my two microphones, say mic1 and mic2, I did a little experiment: I
recorded my voice with mic1, using sox, then listened to the so created .wav
file and the sound was heard only on the left channel.  Instead, doing the same
with mic2, the sound was heard on both channels.  How should we conclude?  It
seems to me that we should conclude that:

1) the mic input on my PC is stereo.  In fact, it is a laptop, nay a netbook,
   doesn't have a line in and it is reasonable that its mic input is also a
   line in;

2) mic1 is mono;

3) mic2 is stereo.

Do you agree?  But then, if it is so, my rough home made live piano record,
done using mic1 and mic2 plugged together in a one-male--two-female splitter,
*is* actually stereo...?

Thanks,

Rodolfo

Re: Live recording

[David Christensen]

On 08/01/17 23:46, Jeremy Nicoll wrote:

On 08/01/17 14:04, Rodolfo Medina wrote:



As much as I can understand, the simplest solution for me to live recording
with several microphones is to buy a - say - 6 channel mixer and plug it into
the line-in PC entry...


If you can possibly afford a multi-channel audio interface, do that
instead.


+1


Most of them provide Windows and/or MacIntosh (OS X) drivers and 
applications.  Finding one with good Linux support will require 
research.  Please post if you find a hardware/software combination that 
is known to work.



David

Re: Live recording

[Jeremy Nicoll]

On Wed, 2 Aug 2017, at 08:07, Rodolfo Medina wrote:
> Jeremy Nicoll  writes:

> > If you do that you'll be recording at most 2 channels,
> 
> 
> Mmmhhh...  this is not clear to me.  Why only two...?  Suppose the mixer
> has 3
> channels, can't I plug three mics into it..?   Say two for the piano and
> the
> third for the voice...?

You described connecting the mixer to your computer's line-in port.  The
line-in is stereo ie 2 channels.

So, yes, you can connect more than 2 mics to a mixer, but then use the
mixer
to mix/merge those signals into just two which you send to the computer.

It mean the decisions on how to do that mix have to be made at the time
of 
the recording... which is not easy if there's background noise, or
hardly any
time to do it, or you are listening on headphones whereas later on you
could 
also listen on speakers...

A multi-channel USB audio interface lets you record all the signals at
the time,
then do the mixing and experiments later.

 
-- 
Jeremy Nicoll - my opinions are my own.

Re: Live recording

[Rodolfo Medina]

Jeremy Nicoll  writes:

> On Wed, 2 Aug 2017, at 06:09, David Christensen wrote:
>> On 08/01/17 14:04, Rodolfo Medina wrote:
>
>> > As much as I can understand, the simplest solution for me to live
>> > recording with several microphones is to buy a - say - 6 channel mixer and
>> > plug it into the line-in PC entry...
>> 
>> That can work.  
>
> If you do that you'll be recording at most 2 channels,


Mmmhhh...  this is not clear to me.  Why only two...?  Suppose the mixer has 3
channels, can't I plug three mics into it..?   Say two for the piano and the
third for the voice...?

Thanks,

Rodolfo


> which means you have
> to decide how to mix the more than 2 mics' signals into a stereo image at the
> venue.  That can be difficult to do, if you can't hear the incoming sounds
> (eg in headphones) clearly, because of background noise, and the decision you
> make then is what you're stuck with later on.
>
> If you can possibly afford a multi-channel audio interface, do that instead.
> Then the mics etc are connected to that external box, which if needed powers
> the mics, amplifies their signals, digitises the analogue signals, then sends
> the digital info via USB (usually) to the computer.  You can then fiddle with
> the balance and everything else later on using software, and experiment with
> different settings.
>
>
>> Make sure you understand phantom power and how you plan 
>> to connect everything before making a purchase:
>> 
>> https://en.wikipedia.org/wiki/Phantom_power
>> 
>> (If you feed phantom power to a device that is not designed to use it or 
>> withstand it, you can get degraded performance and/or destroy equipment.)
>
> Yes; you can also destroy a mic by plugging it into a socket on a mixer while
> the phantom power is on; you need to make sure that phantom is only turned on
> after all the cables are connected.  And turn phantom off again before
> unplugging any powered mics.

Re: Live recording

[Jeremy Nicoll]

On Wed, 2 Aug 2017, at 06:09, David Christensen wrote:
> On 08/01/17 14:04, Rodolfo Medina wrote:

> > As much as I can understand, the simplest solution for me to live recording
> > with several microphones is to buy a - say - 6 channel mixer and plug it 
> > into
> > the line-in PC entry...
> 
> That can work.  

If you do that you'll be recording at most 2 channels, which means you
have
to decide how to mix the more than 2 mics' signals into a stereo image
at the
venue.  That can be difficult to do, if you can't hear the incoming
sounds (eg 
in headphones) clearly, because of background noise, and the decision
you 
make then is what you're stuck with later on.

If you can possibly afford a multi-channel audio interface, do that
instead.  
Then the mics etc are connected to that external box, which if needed
powers 
the mics, amplifies their signals, digitises the analogue signals, then
sends the 
digital info via USB (usually) to the computer.  You can then fiddle
with the 
balance and everything else later on using software, and experiment with
different settings.  


> Make sure you understand phantom power and how you plan 
> to connect everything before making a purchase:
> 
> https://en.wikipedia.org/wiki/Phantom_power
> 
> (If you feed phantom power to a device that is not designed to use it or 
> withstand it, you can get degraded performance and/or destroy equipment.)

Yes;  you can also destroy a mic by plugging it into a socket on a mixer
while the
phantom power is on;  you need to make sure that phantom is only turned
on
after all the cables are connected.  And turn phantom off again before
unplugging
any powered mics.

-- 
Jeremy Nicoll - my opinions are my own.

Re: Live recording

[David Christensen]

On 08/01/17 14:04, Rodolfo Medina wrote:

Rodolfo Medina  writes:


What I want to do is recording live piano: I'd like to use two mics for that,
one on the grave and the other one on the high notes.  Besides, some times I
will need to add human voice: this requires, in my idea, a third
microphone...  But even starting with two would be all right for now...
Those recordings would not pretend to be professional, just home made for my
personal tests, but stereo.



Thanks all for the abundant information and suggestions of possible solutions.


YW.



As much as I can understand, the simplest solution for me to live recording
with several microphones is to buy a - say - 6 channel mixer and plug it into
the line-in PC entry...


That can work.  Make sure you understand phantom power and how you plan 
to connect everything before making a purchase:


https://en.wikipedia.org/wiki/Phantom_power


(If you feed phantom power to a device that is not designed to use it or 
withstand it, you can get degraded performance and/or destroy equipment.)



That I why I wrote:

On 07/29/17 00:10, David Christensen wrote:
> What makes and models of microphones do you have?


David

Re: Live recording

[Fungi4All]

> UTC Time: August 1, 2017 10:45 PM
> From: delop...@gmail.com
> To: debian-user@lists.debian.org
> Rodolfo Medina wrote:
>> Rodolfo Medina  writes:
>>
>>> What I want to do is recording live piano: I"d like to use two mics for
>>> that,
>>> one on the grave and the other one on the high notes. Besides, some
>>> times I will need to add human voice: this requires, in my idea, a third
>>> microphone... But even starting with two would be all right for now...
>>> Those recordings would not pretend to be professional, just home made for
>>> my personal tests, but stereo.
>>
>>
>> Thanks all for the abundant information and suggestions of possible
>> solutions. As much as I can understand, the simplest solution for me to
>> live recording with several microphones is to buy a - say - 6 channel
>> mixer and plug it into the line-in PC entry...
>>
>> Rodolfo
> The simplest way is to use external mixer, but look forward to get one with
> the inputs for low/high impedance (input for mic and line) for each
> channel. Some simple mixers have only 1-2 low (mic) inputs and more high
> inputs. The mic inputs on the mixer are 3 contacts/wires. The line inputs
> are 2 or could be 3 - stereo. Here for example
> http://www.studiomasterprofessional.com/product/item/209
> You could however go the cheep way and play with multiple usb/pci audio
> cards, jack and free audio software
> If you want to experiment with linux and audio recording, you could look for
> a supported multichannel audiocards and play with jack or audacity or some
> other free software which will spare the external mixer.

My cheap and primitive way was to use two pc,s if you already have them, and
record two mono tracks, then use mixing software to align them and blend them.
There is plenty of such software available on debian and the quality is within 
the
guidelines of your mic quality, placement, echo/background noise.
I use headphones for the backing track and rarely use a second mic for guitar
then blend the two. As I have been away from home and haven't done it for a
while don't ask me for names of packages.

Re: Live recording

[deloptes]

Rodolfo Medina wrote:

> Rodolfo Medina  writes:
> 
>> What I want to do is recording live piano: I'd like to use two mics for
>> that,
>> one on the grave and the other one on the high notes.  Besides, some
>> times I will need to add human voice: this requires, in my idea, a third
>> microphone...  But even starting with two would be all right for now...
>> Those recordings would not pretend to be professional, just home made for
>> my personal tests, but stereo.
> 
> 
> Thanks all for the abundant information and suggestions of possible
> solutions. As much as I can understand, the simplest solution for me to
> live recording with several microphones is to buy a - say - 6 channel
> mixer and plug it into the line-in PC entry...
> 
> Rodolfo

The simplest way is to use external mixer, but look forward to get one with
the inputs for low/high impedance (input for mic and line) for each
channel. Some simple mixers have only 1-2 low (mic) inputs and more high
inputs. The mic inputs on the mixer are 3 contacts/wires. The line inputs
are 2 or could be 3 - stereo. Here for example
http://www.studiomasterprofessional.com/product/item/209

You could however go the cheep way and play with multiple usb/pci audio
cards, jack and free audio software
If you want to experiment with linux and audio recording, you could look for
a supported multichannel audiocards and play with jack or audacity or some
other free software which will spare the external mixer. 

Re: Live recording

[Rodolfo Medina]

Rodolfo Medina  writes:

> What I want to do is recording live piano: I'd like to use two mics for that,
> one on the grave and the other one on the high notes.  Besides, some times I
> will need to add human voice: this requires, in my idea, a third
> microphone...  But even starting with two would be all right for now...
> Those recordings would not pretend to be professional, just home made for my
> personal tests, but stereo.


Thanks all for the abundant information and suggestions of possible solutions.
As much as I can understand, the simplest solution for me to live recording
with several microphones is to buy a - say - 6 channel mixer and plug it into
the line-in PC entry...

Rodolfo

Re: Live recording

[Dan Ritter]

On Sat, Jul 29, 2017 at 08:16:00AM +0200, Rodolfo Medina wrote:
> Thanks all of you who kindly provided response.
> 
> What I want to do is recording live piano: I'd like to use two mics for that,
> one on the grave and the other one on the high notes.  Besides, some times I
> will need to add human voice: this requires, in my idea, a third microphone...
> But even starting with two would be all right for now...  Those recordings
> would not pretend to be professional, just home made for my personal tests, 
> but
> stereo.  I must say that the experiments I did with the above rude 
> arrangement,
> i.e. two mics in common Y splitter, inserted into `mic' PC entry, are not so
> bad...

Here are some good steps up in quality:

 Use a good USB microphone array like the Blue Yeti
http://www.bluemic.com/products/yeti/  -- this has two
microphones inside and can typically produce much higher
quality recordings of voice and instruments than anything
plugged directly into your PC's mic port. These are typically
cheaper retail. This is the best value improvement.

Or you can go higher. Use a USB microphone receiver (also known as
a pre-amp/mixer) to connect normal music-quality microphones to your
computer.  For $50 to $100*, you can get 1 to 4 good inputs. If you want
to make professional-sounding recordings, it's easier with something
like this.

* but you can spend incredible quantities of money on
  microphones, and some people do.

-dsr-

Re: Live recording

[Zenaan Harkness]

On Fri, Jul 28, 2017 at 09:11:00PM +0200, Rodolfo Medina wrote:
> According to:
>  http://www.upubuntu.com/2013/05/how-to-record-your-voice-from.html
> I record live sound via microphone just doing:
>  $ sox -t alsa default output.wav
> 
> Now I was wondering about the stereo o non-stereo character of such a home 
> made
> recording...  I tried to use two microphones together, plugging them together
> into the PC with a small common connection doubber.  Can we say the result is
> stereo...?  I would doubt...  and how to have - if possible - a stereo effect
> with the above basic recording instruments?

If your hardware supports it, also a headphone jack can often be
turned into a microphone jack:
http://www.omgubuntu.co.uk/2013/12/turn-headphone-jack-microphone-jack-ubuntu

(Conversely, turn a mic jack into a (mono) headphone jack:
https://askubuntu.com/questions/27804/using-microphone-input-port-as-headphone-output
)

:)

Re: Live recording

[Doug]

On 07/29/2017 01:16 AM, Rodolfo Medina wrote:

/snip/

Thanks all of you who kindly provided response. What I want to do is 
recording live piano: I'd like to use two mics for that, one on the 
grave and the other one on the high notes. Besides, some times I will 
need to add human voice: this requires, in my idea, a third 
microphone... But even starting with two would be all right for now... 
Those recordings would not pretend to be professional, just home made 
for my personal tests, but stereo. I must say that the experiments I 
did with the above rude arrangement, i.e. two mics in common Y 
splitter, inserted into `mic' PC entry, are not so bad... Thanks, Rodolfo 


As has been mentioned, you will need preamplifiers on the two 
microphones, and then combine the preamp outputs into a stereo plug that 
will go into the LINE IN jack on your
sound card. In addition, piano is one of the hardest instruments to 
record properly; it is, after all, a percussion instrument, and as such, 
many microphones cannot deal with it.
If you want anything even approaching a professional result, you will 
have to find microphones that will withstand the dynamics of a piano. 
Also, you will need to deaden the
room acoustics as much as possible. As a minimum, the floor should be 
carpeted, and you will probably want heavy drapes on any windows. 
Overstuffed chairs and/or a sofa
will be helpful also. Any sort of echo will be very distracting to the 
listener to the recording.


--doug

Re: Live recording

[Jeremy Nicoll]

On Sat, 29 Jul 2017, at 09:56, Weaver wrote:

> How almost all professional grand piano recordings are made, whether in
> a concert hall or studio, is with two mics on boom stands, projected
> over the strings. Bass on the left, treble on the right: the way a
> pianist hears it.

As a non-pianist I'd never really thought about the way that a pianist
hears
what they play in such a different way from an audience.

On the other hand, the standard BBC micing of chamber music concerts (eg
for transmission of concerts during the Edinburgh Festival) is (or was
last 
time I was at one) basically a stereo pair slung over the first few rows
of the
downstairs audience.  Sometimes I think they may have used a M mic.

It could be that use of a slung pair is partly so that a standard way of
micing 
the hall works for all the concerts given there over several weeks.

-- 
Jeremy Nicoll - my opinions are my own.

Re: Live recording

[Weaver]

On 2017-07-29 18:27, Jeremy Nicoll wrote:
> On Sat, 29 Jul 2017, at 07:16, Rodolfo Medina wrote:
> 
>> What I want to do is recording live piano: I'd like to use two mics for
>> that,
>> one on the grave and the other one on the high notes.  Besides, some
>> times I
>> will need to add human voice: this requires, in my idea, a third
>> microphone...

How almost all professional grand piano recordings are made, whether in
a concert hall or studio, is with two mics on boom stands, projected
over the strings. Bass on the left, treble on the right: the way a
pianist hears it.
Generally miced up in stereo, not two into one, although two into one is
a good initial check before you split the sound back to stereo.
Mic placement depends very much on the individual piano and can vary
enormously.
Also on what sound or style you're dealing with.
With this in mind, a couple of cardiods right over the hammers can work
well: just look out for the hole in the middle.
If you want a really good mono sound, you will often get it by mounting
a large diaphragm condenser right over the top of the back leg.
If you have the room under the lid, or can get it off altogether, two
omnidirectionals, evenly spaced, about 3' above the springs can work
really well.
Go for the manufacturers recommendations on any of Shure, AKG, or
Sennheiser, and you're generally safe.
Regards,

Weaver 

-- 
"It is the duty of the patriot to protect his country from its 
government."
 -- Thomas Paine

Registered Linux User: 554515

Re: Live recording

[Jeremy Nicoll]

On Sat, 29 Jul 2017, at 07:16, Rodolfo Medina wrote:

> What I want to do is recording live piano: I'd like to use two mics for
> that,
> one on the grave and the other one on the high notes.  Besides, some
> times I
> will need to add human voice: this requires, in my idea, a third
> microphone...

Suppose you were standing next to someone playing the piano.  You'd
think what you were hearing sounded great... and you wouldn't have 
one ear at each end of the piano.

If the piano's in any normal room (ie NOT a sound-deadened area in a
recording studio) part of what you want to hear is also the way the
piano 
sound reverberates around in that space.   Add a voice?  Nothing
changes.

There's many a classical music concert recorded with just one pair of
mics.  The performers balance the sound (so eg the pianist doesn't
drown out a singer) anyway - they have to, for the audience to hear 
a good result.   In a good sounding room or hall (which is something
that most concert or recital rooms are) a decent pair of mics put in the
right place is all you need.

In a crappy room, with background noise, players who can't judge their
own relative volumes, and mics that can't be put in the appropriate 
place... its harder to get a decent result.

The same can be true of an orchestral concert.  Modern tendency though
is often to put a huge number of mics in place, both close to each set
of 
instruments in the orchestra, and eg over areas of it, as well as mics
just 
behind the conductor and further away.  And yet... the conductor's job
is
partly to choose how loud each instrument group should be compared 
with the others at each part of the piece that's being played, and to
manage
that as the performance takes place.  The audience depend on that, as
none
of them will hear whatever is being mixed by the people in the truck
outside
the hall.  I don't really understand why people do it that way.

I've recorded choirs, orchestras, opera etc for maybe 35 years now.  I
have
used multiple mics, but not huge numbers of them.  It's useful eg in a
concert
where a relatively unskilled orchestra and choir are performing
together. More
than likely the choir won't be able to sing loudly enough to be heard
over the
orchestra.  Mics between orchestra and choir help one sort that out -
not for 
the audience - but for a recording produced afterwards.  It can be
useful to 
'spot mic' an instrument that's got to play a solo especially if you
think the
performer might have an attack of nerves and not play loudly enough -
later
you can make them seem a bit louder than they really were. It's useful
to mic
solo singers (singing in front of an orchestra) - partly to catch more
detail of 
the words they're singing... and also to help 'fix' them in the stereo
image.

Concerts in churches (in the UK) often have a U-shaped balcony that
wraps
around the sides and rear of the church.  The sound that a singer
projects
forward from the performance area bounces off the front edge of the
balcony.
Singers sometimes turn their heads as they sing, and that can cause
their
voices to move from side to side in the stereo image... which - once you 
realise what's going on - can sound very peculiar.  A spot mic on a
singer
can let you - say - add just a little of their voice in a fixed (eg just
to the left
or right of centre) part of the stereo image.

-- 
Jeremy Nicoll - my opinions are my own.

Re: Live recording

[David Christensen]

On 07/28/17 23:16, Rodolfo Medina wrote:

What I want to do is recording live piano: I'd like to use two mics
for that, one on the grave and the other one on the high notes.


Using microphones well is a fine art/ black art.  Here are some articles
related to miking pianos:

http://howtomic.com/how-to-mic-a-piano/

http://www.shure.eu/support_download/educational_content/microphones-basics/piano

http://www.soundonsound.com/techniques/piano-recording

http://www.audio-technica.com/cms/site/04f76e2b2512882b/


What kind of piano?


What makes and models of microphones do you have?



Besides, some times I will need to add human voice: this requires, in
my idea, a third microphone...


Now you're talking multi-track recording and/or mixing.



But even starting with two would be all right for now...  Those
recordings would not pretend to be professional, just home made for
my personal tests, but stereo.


Why stereo?  Stereophonic provides a left/right positional sound field 
with direct sound and environmental cues to stimulate the listener. 
Wide bandwidth is "high fidelity"; a good monophonic recording and 
full-range loudspeaker can do this.




I must say that the experiments I did with the above rude
arrangement, i.e. two mics in common Y splitter, inserted into `mic'
PC entry, are not so bad...


An inexpensive computer microphone (e.g. SoundBlaster) plugged into a PC
should have a good bang/buck ratio.


A step up using a PC would be an audio interface device:

http://www.tascam.com/applications/recording/pc_audio_interface/

plus some microphones:

http://www.tascam.com/applications/recording/microphones/


Another option is a purpose-built recording device:

http://www.tascam.com/applications/recording/handheld_recorder/


It's just a matter of time, money, and expectations.  A lot of this
stuff can be bought used for a fraction of the new price.


David

Re: Live recording

[deloptes]

Rodolfo Medina wrote:

> What I want to do is recording live piano: I'd like to use two mics for
> that, one on the grave and the other one on the high notes.  Besides, some
> times I will need to add human voice: this requires, in my idea, a third
> microphone... But even starting with two would be all right for now... 
> Those recordings would not pretend to be professional, just home made for
> my personal tests, but stereo.  I must say that the experiments I did with
> the above rude arrangement, i.e. two mics in common Y splitter, inserted
> into `mic' PC entry, are not so bad...

So buy a simple 4-6 channel mixer.
2 mic for piano
1mic for voice
1-3 lins are left if you want to add some other instrument
I would go actually for at least 6 channel mixer.

you can of course add few more audio cards to the PC, but you'll need
additional processing/recording power.

regards

Re: Live recording

[Rodolfo Medina]

David Christensen  writes:

> On 07/28/17 12:11, Rodolfo Medina wrote:
>> According to:
>>
>>  http://www.upubuntu.com/2013/05/how-to-record-your-voice-from.html
>>
>> I record live sound via microphone just doing:
>>
>>  $ sox -t alsa default output.wav
>>
>> Now I was wondering about the stereo o non-stereo character of such a home
>> made recording...  I tried to use two microphones together, plugging them
>> together into the PC with a small common connection doubber.  Can we say the
>> result is stereo...?  I would doubt...  and how to have - if possible - a
>> stereo effect with the above basic recording instruments?
>
> Connecting two monophonic microphones in parallel with a connection splitter
> run backwards will yield a monophonic signal with reduced gain and time/
> frequency signal artifacts such as comb filtering and echo. For most
> applications, the result will not be acceptable.
>
>
> Capturing sound with two microphones can be done several ways:
>
> https://en.wikipedia.org/wiki/Stereophonic_sound#Recording_methods
>
>
> Computer microphone port(s) are typically monophonic and the line input
> port(s) are typically stereophonic.  If you want to record in stereo, you
> need to provide left and right channel signals to the line input port.
>
>
> Computer microphone ports and line input ports also expect different voltages
> and have different impedance.  I believe computer line input ports are
> designed to consumer audio equipment standards -- e.g. -10 dBV into 10 kOhm
> for 0 VU:
>
> https://en.wikipedia.org/wiki/Line_level#Nominal_levels
>
>
> (For microphone ports, my guess would be -30 dBV into 1 MOhm.)
>
>
> This means you need two microphone pre-amplifiers and/or a stereo mixer with
> two or more microphone inputs:
>
> https://en.wikipedia.org/wiki/Line_level#Line_level_in_traditional_signal_paths
>
>
> The audio capabilities of Linux have evolved over the years:
>
> https://en.wikipedia.org/wiki/Open_Sound_System
>
> https://en.wikipedia.org/wiki/Advanced_Linux_Sound_Architecture
>
>
> Sox is a command-line tool that has been around since 1991:
>
> https://en.wikipedia.org/wiki/SoX
>
>
> Audacity is my favorite interactive audio recording and editing tool:
>
> https://en.wikipedia.org/wiki/Audacity_(audio_editor)
>
>
> If you would care to explain your application, we might be able to give more
> advice.


Thanks all of you who kindly provided response.

What I want to do is recording live piano: I'd like to use two mics for that,
one on the grave and the other one on the high notes.  Besides, some times I
will need to add human voice: this requires, in my idea, a third microphone...
But even starting with two would be all right for now...  Those recordings
would not pretend to be professional, just home made for my personal tests, but
stereo.  I must say that the experiments I did with the above rude arrangement,
i.e. two mics in common Y splitter, inserted into `mic' PC entry, are not so
bad...

Thanks,

Rodolfo

Re: Live recording

[David Christensen]

On 07/28/17 12:11, Rodolfo Medina wrote:

According to:

 http://www.upubuntu.com/2013/05/how-to-record-your-voice-from.html

I record live sound via microphone just doing:

 $ sox -t alsa default output.wav

Now I was wondering about the stereo o non-stereo character of such a home made
recording...  I tried to use two microphones together, plugging them together
into the PC with a small common connection doubber.  Can we say the result is
stereo...?  I would doubt...  and how to have - if possible - a stereo effect
with the above basic recording instruments?


Connecting two monophonic microphones in parallel with a connection 
splitter run backwards will yield a monophonic signal with reduced gain 
and time/ frequency signal artifacts such as comb filtering and echo. 
For most applications, the result will not be acceptable.



Capturing sound with two microphones can be done several ways:

https://en.wikipedia.org/wiki/Stereophonic_sound#Recording_methods


Computer microphone port(s) are typically monophonic and the line input 
port(s) are typically stereophonic.  If you want to record in stereo, 
you need to provide left and right channel signals to the line input port.



Computer microphone ports and line input ports also expect different 
voltages and have different impedance.  I believe computer line input 
ports are designed to consumer audio equipment standards -- e.g. -10 dBV 
into 10 kOhm for 0 VU:


https://en.wikipedia.org/wiki/Line_level#Nominal_levels


(For microphone ports, my guess would be -30 dBV into 1 MOhm.)


This means you need two microphone pre-amplifiers and/or a stereo mixer 
with two or more microphone inputs:


https://en.wikipedia.org/wiki/Line_level#Line_level_in_traditional_signal_paths


The audio capabilities of Linux have evolved over the years:

https://en.wikipedia.org/wiki/Open_Sound_System

https://en.wikipedia.org/wiki/Advanced_Linux_Sound_Architecture


Sox is a command-line tool that has been around since 1991:

https://en.wikipedia.org/wiki/SoX


Audacity is my favorite interactive audio recording and editing tool:

https://en.wikipedia.org/wiki/Audacity_(audio_editor)


If you would care to explain your application, we might be able to give 
more advice.



David

Re: Live recording

[Jeremy Nicoll]

On Fri, 28 Jul 2017, at 20:11, Rodolfo Medina wrote:
> Hi all.
> 
> According to:
> 
>  http://www.upubuntu.com/2013/05/how-to-record-your-voice-from.html
> 
> I record live sound via microphone just doing:
> 
>  $ sox -t alsa default output.wav
> 
> Now I was wondering about the stereo o non-stereo character of such a
> home made
> recording...  I tried to use two microphones together, plugging them
> together
> into the PC with a small common connection doubber.  Can we say the
> result is
> stereo...?  I would doubt...  and how to have - if possible - a stereo
> effect
> with the above basic recording instruments?

If you have a sound-card, or external 'audio interface' that can process
signals from 
more than one channel at once, then you can record either 'double mono'
or 
stereo.

Which you get depends on the directional characteristics of the
microphones and 
how they are positioned relative to each other.  Stereo is not just two
sounds at 
once, but (generally) two sounds captured at the same point in space. 
Sound
recordists would usually use a pair of 'cardioid' response mics,
arranged in what's
called an 'X-Y' or 'crossed-pair' configuration.  You can google these
terms.


-- 
Jeremy Nicoll - my opinions are my own.

Re: Live recording

[deloptes]

Rodolfo Medina wrote:

> Now I was wondering about the stereo o non-stereo character of such a home
> made recording...  I tried to use two microphones together, plugging them
> together into the PC with a small common connection doubber.  Can we say
> the result is stereo...?  I would doubt...  and how to have - if possible
> - a stereo effect with the above basic recording instruments?
> 
> Thanks for any reply,
> 
> Rodolfo

Hahaha, Rodolfo you made my day. It was anyway a hard week, so good that I
read your post :)

The mic is mono, so the input if I am not wrong is mono as well.
Check of course the specs of your board. On my one (pretty standard) it
says:

Interfaces
Audio: line-in  1
Audio: line-out 1
Front audio: microphone 1
Front audio: headphone  1

in linux language

$ amixer
Simple mixer control 'Master',0
  Capabilities: pvolume pswitch pswitch-joined
  Playback channels: Front Left - Front Right
  Limits: Playback 0 - 65536
  Mono:
  Front Left: Playback 11477 [18%] [on]
  Front Right: Playback 11477 [18%] [on]
Simple mixer control 'Capture',0
  Capabilities: cvolume cswitch cswitch-joined
  Capture channels: Front Left - Front Right
  Limits: Capture 0 - 65536
  Front Left: Capture 7353 [11%] [on]
  Front Right: Capture 7353 [11%] [on]

$ ls -1 /dev/snd/
by-id
by-path
controlC0
controlC1
hwC0D2
pcmC0D0c
pcmC0D0p
pcmC0D2c
pcmC1D0c
seq
timer

pcmc is capture device (p is playback)

The mic has also different Ohms or perhaps better to say impedance, so I am
not sure if it would work, but you could try plugging those mics to the
line in, not the mic.

So line in, is the stereo one. I think if you plugin mic(s) without preamp,
because of the high Ohms, it would be very silent, but still worth a try.

You need a stereo jack to L-R like this one
https://www.thomann.de/at/pro_snake_78219_yadapterkabel.htm

This way you'll also know if it is true stereo, because if you unplug the
one mic, it would record only on the other channel. Of course you can see
this in audacity or even with arecord

However I am not sure what would be the purpose of all this, but you know
perhaps better

regards