[LAU] Surround Mixing & Ambisonics

Ray Rashif schivmeister at gmail.com
Sat Aug 15 19:58:03 EDT 2009

Good day all

I've recently gotten interested in recording & mixing in surround, which led
me to Ambisonics as well. I've noticed Fons has a good deal of contribution
to that field, judging from his tools (ambdec et al) and credits.

My first stumbling block is how one would go about the mixing process for
such a project, especially since none of our DAWs have (true) support for
surround. Granted, there are ways to work around it, especially if one
doesn't need fancy 360-degree panning UIs. For instance, although I've not
tried it yet, theoretically one can stream separate tracks to ac3jack. Each
track can have its own panning relative to front and rear groups, and since
conventional surround (not ambisonics) has no height information, that'd be
adequate. I don't know if existing surround VST plug-ins could be used
within Ardour properly.

Secondly, would the tools from http://www.kokkinizita.net/linuxaudio/ be
enough for ambisonics? I notice that there is only a decoder, but for
mixing, one needs an encoder (which I understand to be the panning and
bussing of WXYZ). Is there any native tool to help with that?

Third and _most_ important of all, is it possible to listen to the _virtual_
surround image in real-time through stereo? IIRC, Windows has/had these neat
little utilities provided by vendors to recreate 3D (virtual) surround with
n number of speakers, marketing to the 2-channel stereo crowd. Any surround
audio being streamed by the system would fall back to this 3D thing if no
surround hardware is available. Not sure whether the same applies for an
ASIO environment. If not, I may be asking for something which has not yet
been developed.

Considering that ALSA has a "plug-in" for downmixing multi-channel audio,
and it works OK, could there be a way to use it/something similar within a
JACK environment? It'd really help when I'm recording live, eg. an
orchestra, with surround miking and no more than just a monitoring
headphone. Something like ac3jack, but with some sort of virtual surround
output option.

Fourth and least important, is there a native tool for converting audio to
5.1 (or so thereof) with panners? I have a Zoom H2 which outputs 4 channels
(front and rear stereo) and don't want to rely on the VST that's available.
Sometimes I just happen to need fast methods, especially when I'm mobile.

-------------- next part --------------
An HTML attachment was scrubbed...
URL: http://lists.linuxaudio.org/pipermail/linux-audio-user/attachments/20090816/f136f72f/attachment.htm 

More information about the Linux-audio-user mailing list