Rui Nuno Capela wrote:
> Ralf Mardorf wrote:
>   
>> Hi Rui :)
>>
>>     
>>> mono recording/playback in qtractor is perfectly possible provided you
>>> use
>>> a mono audio bus (channels=1) for track input/output.
>>>
>>> otherwise, the default master buses are stereo (channels=2) and mono
>>> signals are replicated on input and doubled on output.
>>>   
>>>       
>> The default master buses should be stereo. Is Qtractor able to replicate
>> the signal?
>>
>>     
>>> remember, wrt. qtrator, all your audio track's behavior is determined by
>>> their assigned buses modes: recording will be mono if track's input
>>> bus is
>>> mono, there playback will be replicated to each output bus channel.
>>>
>>> afaict, this pseudo-mono/stereo conversion should not introduce any
>>> phasing artifacts as the duplication/doubling process is done in the very
>>> same and precise computational audio period cycle.
>>>   
>>>       
>> I did it by JACK, connected the mono signal to both sides of Qtractor's
>> input.
>>
>>     
>>> if some phasing can be possible heard, there must be regarded to be
>>> due on
>>> and after the signal goes through D/A conversion.
>>>       
>> Then there must be phases for other signals too, the same if my mixing
>> console or some cables would be phased. But the signal only is that bad,
>> when I "convert" mono to pseudo-stereo by JACK connections.
>>
>>     
>>> maybe your monitors are
>>> out of phase
>>>       
>> Even if the monitors would be out of phase, I routed the subgroups by my
>> external mixing console to mono and listened to the signal by just one
>> side of my headphones, that only has one speaker, so nothing could be
>> out of phase in relation to something else, only the "layered" signals
>> could be phased. But anyway, nothing of my equipment is phased ;).
>>
>>     
>>> or some other psycho-acoustics phenomena going in there, perhaps? :)
>>>
>>> cheers
>>>   
>>>       
>> No, there're definitive phases when a mono signal by one channel is
>> connected by JACK to both channels of a stereo input. If JACK gets a
>> mono signal already as pseudo-stereo and this pseudo-stereo signal is
>> connected to a stereo channel, there are no phases.
>>
>> I won't report it to the JACK list, because it's useless if I report
>> this. When I said JACK is producing noise to some people, before I was
>> described to the JACK list, I was the troll, 2 years later a JACK coder
>> noticed it and was the hero. If an engineer like me hears something he
>> is always wrong, we need to wait if a coder notices something in the
>> code, e.g. for the noise it was a rounding error IIRC. It was the same
>> with the sync problem, when I noticed it, nobody was interested, it took
>> a long time until other people, e.g. Daniel from 64 Studio reported the
>> same problem for sync, before anybody was willing to listen.
>>
>>     
>
> i think, MHO, your trouble with the lads (ie. the coders) is that most
> of the time you're too subjective for their objective taste, so to speak :)
>
> personally, i don't consider you as a troll. actually i often find you
> asking pertinent questions and issues, as long as i skip your sometimes
> harsh rhetoric ;)
>
> now... cut! let's get back to the mono/stereo phasing issue: may i ask
> you consider the help of jaaa and ultimately ask how it can help you
> figure whether there's something fishy (or "phasy", my own neologism)
> either in jack or in qtractor.
>   

No I never used JAAA. I don't know this application. How can I check 
phases for a "layered" mono signal? Send the mono and "layered" mono 
signal as left, right to a phases correlator?

>> Btw. I'm running JACK2. I have to add that I sometimes run JACK with
>> options that aren't fine with the hardware, but as long as there are
>> no error messages and warnings, e.g. xruns, this shouldn't cause any
>> trouble.
>>
>>     
>
> damn, it ocurred to me that the parallelizing feature of jack2 (formerly
> jackdmp) might be doing it on different period cycles with at least one
> buffer period delay between each channel/port. indeed, i'll suggest you
> have jaaa report some evidence and/or reinstall jack1 and check if
> things sound any different.
>   

I can't use JACK1, because than I can't use Linux to make music, because 
JACK1 disconnect clients "without any reason".
I'll write a report, if I'll should be fine with JAAA ;).

To be honest, I don't really need to set up a mono connection this way 
by JACK, it was a exceptional case and seems only appear for this 
situation, for any other kind of connection I never heard anything, 
maybe I should check if JAAA can make something visible that I'm unable 
to hear.

>> Anyway, I used Qtractor to play note events and recorded the mono signal
>> by Audacity. Because I don't have MIDI jitter when I use Qtractor with
>> fluidsynth-dssi, I'm making soundfonts of some external synth.
>>
>> Okay, this mono issue seems to belong to JACK, but not to Qtractor.
>>
>>     
>
> i'll keep my fingers crossed :)
>   

I'm to lazy today. But I did the connection by JACK2 and Qtractor was 
running like it runs all the time, with the normal stereo bus. When I'm 
busy again I can simply connect system capture_1 to system playback_1 
and playback_2. I'm sure Qtractor has nothing to do with it.

>> I still like Qtractor :), but had some crashes. I can't report exactly
>> what caused the crashes, but there seems to be a coherence with plugins.
>> At the moment I need to do other things, but I'll report when exactly
>> this crashes will occur as soon as possible.
>>
>>     
>
> plugins are hell, specially the vst ones :) otoh, at least on my
> experience, fluidsynth-dssi is one hell of a crashy thing when linked to
> libfluidsynth >= 1.0.9 ; libfluidsynth 1.0.8 seems to have no such
> nasties. ymmv
>
> seeya

It happens with fluidsynth-dssi and/ or Echo Delay Line LADSPA. I 
remember you once told me that libfluidsynth is bad and I made an error 
in reasoning, because I compile always latest CVS version of Qtractor, I 
thought the problem will be solved :D, pardon, I've forgotten that it 
was a problem because of libfluidsynth. Libfluidsynth is 1.0.7a for my 
64 Studio.

Thanx for your effort,
Ralf
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