This is good to keep in mind. Have you ever seen the ICST plugins for max msp? Those objects have a method of putting in xyz coordinates for its ambisonic decoders. Where I work at, we use this to output ambisonics to all of our spaces at ICAT, including the Cube. It does work well, but I do know of colleagues who complain about how "fuzzy" the spatialization is. Do these kinds of decoders fudge the decoding to achieve output? I really want to find something like this for Linux.1. Computing decoders for arbitrary speaker positions is still some sort of 'black art' unless the postions form a more or less regular grid. Don't believe everything about automated methods claiming to do this.
The reason I ask is because I want to find a Linux-based system for the Cube, which has 138 speakers arranged in a rectangular prism. I am constantly looking for a way to decode ambisonics to it without having to use max msp. I have not had much luck finding something standalone or in pd. Maybe I should learn supercollider? It can be hard to find decoders that go to 10th or 11th order.3. I really can't imagine anything done with speakers that would require 7th order. Even with 4th or 5th order, if you have enough speakers to use that, the angles between the speakers are so small that even phantom images in between speakers are for all practical purposes perfect.
At work, I may be getting hold of 64 AVB speakers that I can arrange in a line to experiment with WFS. The great thing about this is the speakers are AVB, and not Dante. I may be able to play with these speakers on Linux. Of course, there is at least one WFS processor (is that the right term?) that I know of in max. But, I find max too annoying and locked down for real use, and of course I want to do it on Linux!4. To do anything similar to WFS 'internal sources' (i.e. in front of the speakers) in any practical frequency range, you'd need the same amount of speakers as WFS would, and of course the required very high order input.
Thanks for the detailed points,
Brandon Hale
On Fri, Feb 26, 2021 at 11:58:28AM -0500, Brandon Hale wrote:Ambdec looks nice, but I wish there wasn't a limit on order. 36 speakers may not be enough for me. Do you know of anything for beyond 7th order? I wasn't clear enough in my original email, but I am really looking for something that can go past 7th order and can do any speaker placement.Ambdec is currently limited at 3rd order, but that could be increased. Also it does not compute the actual decoder coefficients, these have to be supplied in a preset file. Keep in mind that 1. Computing decoders for arbitrary speaker positions is still some sort of 'black art' unless the postions form a more or less regular grid. Don't believe everything about automated methods claiming to do this. 2. Higher order means more speakers. 7th order would require at least 64, assuming they are in a regular grid, and probably a lot more if they are not. Less speakers would mean that the information in the higher orders can't be used, and any correctly computed decoder will actually just ignore such information. 3. I really can't imagine anything done with speakers that would require 7th order. Even with 4th or 5th order, if you have enough speakers to use that, the angles between the speakers are so small that even phantom images in between speakers are for all practical purposes perfect. 4. To do anything similar to WFS 'internal sources' (i.e. in front of the speakers) in any practical frequency range, you'd need the same amount of speakers as WFS would, and of course the required very high order input. Ciao,