Can you describe your 2d space a little? Is there a reason for wanting 48 discrete spots rather than one continuous space? I actually think the 48 spots could work, but I'm curious how it is supposed to sound when something "moves" through the space (or do sounds just pop up periodically at those discrete spots)?
There is another ambisonic trick I have heard of but haven't yet tried, which is to add a 3rd dimension in the encoding but still decode to a 2d space. The space then becomes a kind of projection of the 3d space onto a 2d space, so you can "move closer to the center" by increasing the "elevation" of the direction. "Directly upwards" in the encoding sends the same signal to all 4 speakers on decode, so that it sounds "in the middle" of the space.
Matt
On Mon, Mar 14, 2011 at 10:22 AM, J bz jbeezez@gmail.com wrote:
Hey Matt,
Thanks for pushing my understanding along...
I should have said that the pan positions are constantly shifting for 48 separate points within the x-y grid so would be, I presume, heavily cpu intensive with some of the solutions you propose. The patch is running off the performers lappy and is already doing a lot within Pd.
My supervisor, the composer Aaron Cassidy, thought that as the GEM window is projected as part of the performance with the msd swarm, that it is somewhat 'dishonest' to only have a stereo field when the visuals are obviously moving on the y plane as well. And annoyingly I have to agree with him. You know when someone has said something and one feels (me in this case) that the genie is out of the bag and there is no going back.
Cheers,
Julian
On 14 March 2011 13:48, Matt Barber brbrofsvl@gmail.com wrote:
Ambisonics isn't necessarily overkill, but it only gets you direction, not distance -- it's only a "1-dimensional" solution, in the sense that you'd be panning around the outside of a circle but not to locations within that circle. It's not terribly CPU expensive. If you do want distance as well you can use some combination of delay, low-pass filtering, and wet-dry mix of any reverb you happen to be using (and if you want to get really ambitious, you can also simulate individual room reflections). This starts to get CPU intensive especially if you're going to be moving sounds around. If they just stay in place, it's not as bad (and the [delwrite~] [vd~] model doesn't actually model moving sources a certain distance from the virtual "microphone" -- it models a moving microphone, so a simple Pd solution isn't quite available).
Matt
Hey all,
So I'm still scratching my head with controlling audio panning in an x,y grid using 4 speakers.
What, at first, seemed like a somewhat trivial problem, upon closer inspection ain't necessarily so.
Does anyone have examples of panning with 4 speakers? About the only things I have found so far are: Building upon Hans' [pan_core~] [pan_quad~] from 'nSLAM', which seems to be unavailable for d/l The 'pd-tutorial' patch
3-9-3-1-spatial-quadro.pdhttp://pd-tutorial.com/english/patches/3-9-3-1-spatial-quadro.pd
Anyone know about any others?
My stereo panning is built upon the square root example in Andy Farnell's book, which I'm really happy with. Ideally I would like to expand upon that.
Then of course there is the whole vbap/ambisonics/cubemixer (possible overkill) route too. My concerns before diving into this are threefold.
- If it's only going to work for the 2 people in the 'sweet-spot' then
what's the point? If it makes any difference I'm using some Bose 180 degrees radiating speakers.
- The piece is for a performer with electronics, with only the
electronics coming out of the speakers. So I'm also wondering whether a 5.1 type setup with the performer as the front centre speaker (as such), may be preferable?
- The piece requires 96 separate pan positions - how cpu intensive is
that going to be? It currently works fine in stereo, which is why 2 lots of stereo in an x,y fashion seems initially preferable.
I'm aware that it's pretty much impossible with this speaker setup to make everyone in the room have a similar audio experience, and also to map my visual masses from an msd swarm in the GEM window as audible points, but surely it is possible to do this as an x,y grid.
I also admit that I don't understand the dsp theory necessary to make the x,y, grid idea happen so if anyone has some pointers regarding that I would be delighted.
Cheers,
Jb