On 2012-10-05, Eric Carmichel wrote:
(Ville, once again the reason why I linked you in is to be found lower
down the post.)
Surround controllers, on the other hand, are generally limited in
their number of channels or become expensive. One solution to my
'dilemma' was to use a DAW surface controller. The simplest
implementation of this idea was an attempt to use a MIDI volume
controller to remotely control the Master fader.
Early vector synths possess joysticks well integrated with MIDI. What
you'd need then is a counterpart which can parse the serial MIDI stream
and make it into a) a continuous stream of panning points and b) into go
interpolation between them, despite c) the two separate controller
value updates arriving at different times, with no other time
information to connect them together.
I've never seen a controllee which could do this sort of stuff. If you
want to get somebody to implement this stuff, in a production level
thingie, I'd seriously consider contacting Charlie Richmond.
A kit available from midikits.net23.net provided an easy to build and
flexible solution. This is a hardware device with a USB interface that
serves to control the (software) Master fader.
Over MIDI the best solution would prolly be the standard pan controller
used for a mid/Y channel, combined with a proprietary controller for
X/side channel. Two more if you're dealing with full W-format, for
W'==W-X-Y, and W-Z. Roughly speaking.
But by building my own preamp, I achieved a large channel count by
using serially-connected Burr Brown PGA2311 ICs.
Why not go all-digital, with something like the (Cirrus derived, I
belive) Crystal CS4234 or the like? Those puppies can be coaxed to work
in full tandem as well, or at least synched to analog-kind perfection.
A single rotary pulse encoder controls all channels, but now I have
the added benefit of software control.
A Gray coded knob works pretty well with digital electronics.
Thanks to all who wrote. The info on Richard Furse's site helped
immensely.
They always do. I'd very much like to have a zipped or otherwise
compressed representation of every site out there, for preservation, as
well. Not always because I want to redistribute the stuff as part of the
Motherlode, but simply because I believe in offline preservation of the
Good Stuff as well.
Regarding my 6th (or roaming speaker): This channel stands alone for a
few reasons that I didn't explain but will comment on here: First, my
current study involves SNRs in reverberant environments. The primary
noise source is talkers and room reflections... specifically, talkers
at a distance. The signal is speech from a nearby talker. This
represents a scenario found in restaurants, and a listening condition
that is difficult for cochlear implant users. [...]
That's a research application. Do you already have a format in which to
present/preserve both your source data and your conclusiosn? I could
help select a few, or then participate in developing yet another one.
(I'm a data representation freak even above my capacity as an ambisonic
and relational database one.)
This way, I use a handheld response box containing, say, 8 words
written on push-buttons, and the subject simply pushes the buttons in
the order the words are heard.
As a hearing deficited person who knows a bit about auditory tests and
statistics, I believe that design is a bit dangerous on multiple
fronts...
(Keyboards or word recognition software to collect responses becomes
unwieldy and unreliable). When the listener makes x consecutive
mistakes, the SNR is automatically improved to make listening easier
(or decreased to make it more difficult in the case of consecutive
correct responses).
Optimally you'd do an interpolation search over the whole SNR range, for
speed, and with stochastic backrack, in order to get tighter error bars.
The noise is surround noise via an Ambisonic set up and auralizaton/or
live recordings of restaurant noise.
In here, I'd seriously suggest you compare your notes with what Ville
Pulkki and his research team did with DirAC. It is *highly* doubtful
whether background noise played over a low order ambisonic system
actually masks direct sounds the way real life noise does. In fact it's
almost certain it doesn't -- once you rerandomize the nondirectional,
"noise" component, even via computational means starting with a
soundfield recording, suddenly the soundfield takes on a much more
natural and extended quality. Over which I at least, as a hearing
impaired person, compensate my problem much better than over a low order
ambisonic noise field. I've never seen the end result measured in a
proper fashion, but if they were, I'd guess the difference between a
fully randomized disperse ground and a one played back via first order
ambisonic could be as much as 10-15dB, at least for people like me.
Although reverberant noise is generally diffuse, localization cues and
"glimpsing" aid the listener in segregating and understanding the
signal. At least that's the idea.
Prolly true. Just mind the fact that correlated and uncorrelated
background "hum" are rather different as masking signals.
I have an array of speakers at home, but data collected from a living
room hardly qualifies as "controlled" or scientific.
If it's well-designed, it actually does count. Because we can't always
fully know what happens in even the best (or the worst) of living
spaces, unless we actually try them out. So, once again, one of the
things Ville Pulkki showed me at one time was something you might call
"a research quality, optimal, living room". Acoustically well damped and
dispersed, but by no means dead as the room upstairs; that's where he
made me a believer in computational randomization of the soundfield.
Upstairs, in the anechoic one, was where he convinced me about the fact
that more speakers in ambisonic playback isn't always better. ;)
This was why I was wondering whether an Ambiophonic-Ambisonic hybrid
system might be possible.
It is, and it has been done already. Just browse over the Ambiophonics
site, and look for Ralph's and Robin's publications. E.g. something they
call "panorambiophonics"
http://www.ambiophonics.org/files/AES24Banff_1.html .
Ideally, I'd like to construct a system that is portable.
There, go with digital, always, n'est ce pas?
Gobos and flats may work, particularly if they are constructed of
materials that provide absorption across the speech spectrum of
frequencies. Low-frequency absorption via a gobo would be a more
daunting task, though the right combo of mass and compliance could
yield a low Q absorber. Just ideas...
Physical acoustics about such complicated objects aren't the forte of
most people around here, I think. Not mine at least -- yet there are
some like Filippo (Fazi), Robert (Greene) and Angelo (Farina) who've
been there and done that already, or at least eat the math for lunch.
In the meantime, I continue to enjoy make Ambisonic field recordings
solely for the fun of it. My last recording was an attempt to record a
bald eagle at a nearby lake. Most of what I captured was an agitated
squirrel and a flying insect that found the mic's windscreen to be a
good landing pad. Fun effects!
For the longest time I've wanted to bring a full 3D mic into a BDSM
party. I'm used to flying with that crowd, after all. There, you don't
have to wait for the squirrel to squeak. It's just that there -- for
some odd reason -- people are somewhat wary of letting any kind of
recording device near...their arse. ;)
--
Sampo Syreeni, aka decoy - [email protected], http://decoy.iki.fi/front
+358-50-5756111, 025E D175 ABE5 027C 9494 EEB0 E090 8BA9 0509 85C2
_______________________________________________
Sursound mailing list
[email protected]
https://mail.music.vt.edu/mailman/listinfo/sursound
