<html><head><meta http-equiv="Content-Type" content="text/html; charset=UTF-8" /></head><body style='font-size: 10pt; font-family: "Courier New",Courier,monospace'>
<p>Thanks Winfried - this looks exciting! Digging into this library now!</p>
<div> </div>
<p>-Jesse</p>
<p>On 2017-06-29 11:00, Winfried Ritsch wrote:</p>
<blockquote type="cite" style="padding: 0 0.4em; border-left: #1010ff 2px solid; margin: 0"><!-- html ignored --><!-- head ignored --><!-- meta ignored -->
<div class="pre" style="margin: 0; padding: 0; font-family: monospace">Hello,<br /><br /> Theoretically, with Ambisonics any configuration of loudspeaker outside a <br /> listening spot, with speaker in distance which Produce a kind of plane <br /> wavefield is suitable for Ambisonics. The better the speaker sound, the <br /> better the whole system, but it is robust for individual speaker differences <br /> as long you calibrate it and has a way better energy distribution than vbap <br /> for small speaker. Of course, if speaker missing on some side there can be no <br /> sound from there, but placing virtual speaker for decoder makes smoother <br /> transistions to this direction and so on, best follow the advices in <br /> Ambisonics Decoder Toolbox [ADT] by Aaron J. Heller [<a href="https://bitbucket.org/ambidecodertoolbox/adt.git">1</a>] to calculate a <br /> decoder.<br /><br /> Anyhow we are on the way for a Pd Ambisonics library for "Imperfect Ambisonics <br /> Systems". Which also means in rooms with "bad acoustics" or any other odd <br /> places, mixed speaker setup and so on. You are invited to join to extend this <br /> simple abstraction lib.<br /><br /> <a href="https://git.iem.at/pd/acre-amb">https://git.iem.at/pd/acre-amb</a><br /><br /> By the way it supports multichannel patching with names as buses and so on, to <br /> reduce Pd-cabling. (Note it is in development and should be stable end of <br /> summer).<br /><br /> Next week we want to finalize the new Ambisonics domeplayer [<a href="https://iaem.at/kurse/projekte/aaas2/iemkit_6ch.jpg">2</a>] for AAAS <br /> (affordable autonomous Ambisonics system) for the workshop in September (and <br /> publish it on git).<br /><br /> [1] <a href="https://bitbucket.org/ambidecodertoolbox/adt.git">https://bitbucket.org/ambidecodertoolbox/adt.git</a> )<br /> [2] <a href="https://iaem.at/kurse/projekte/aaas2/iemkit_6ch.jpg">https://iaem.at/kurse/projekte/aaas2/iemkit_6ch.jpg</a><br /><br /> rfc<br /> winfried<br /><br /> Am Samstag, 24. Juni 2017, 11:26:59 schrieb Pierre Guillot:
<blockquote type="cite" style="padding: 0 0.4em; border-left: #1010ff 2px solid; margin: 0">Hi Jesse,<br /><br /> With Ambisonics, ideally your loudspeakers should discretize perfectly a<br /> sphere, you should have your head at the exact center of this sphere, etc.<br /> and perhaps if you forget that your head interferes and the loudspeakers<br /> don't generate plane waves you'll be able to reconstruct a coherent sound<br /> field... But to avoid these restrictions (because very few people have a<br /> full sphere of loudspeakers - or want to ask the audience to be completely<br /> crushed at the center of the sphere) there are several techniques :<br /> optimizations of the energy and/or velocity vectors, optimizations of the<br /> decoding, etc. The problem is that none of the solutions are completely<br /> generic. Your choice must be driven by your approach and your goal.The<br /> advantage of Ambisonics lies in its intermediary representation of the<br /> sound field that allows to apply transformations (rotation or whatever) and<br /> to decode for different loudspeakers configurations. But if you just want<br /> to spatialize individuals point sources, you can also use VBAP that is<br /> perhaps much more accessible. Nevertheless yes, you can surely find a way<br /> to decode the sound field for two ring of loudspeakers with Ambisonics (we<br /> can discuss it if you want). And one good rule is just to avoid placing<br /> sources where the loudspeakers are missing. I don't know if I really answer<br /> the question, I hope a bit :)<br /><br /> Cheers,<br /><br /> Pierre<br /><br />
<blockquote type="cite" style="padding: 0 0.4em; border-left: #1010ff 2px solid; margin: 0">Date: Fri, 23 Jun 2017 16:19:29 -0600<br /> From: <a href="mailto:jmejia@anestheticaudio.com">jmejia@anestheticaudio.com</a><br /> To: <a href="mailto:pd-list@lists.iem.at">pd-list@lists.iem.at</a><br /> Subject: [PD] HOA / spatialization approaches for a hemisphere<br /> Message-ID: <<a href="mailto:3149263781acf8439b762eef943d60e5@anestheticaudio.com">3149263781acf8439b762eef943d60e5@anestheticaudio.com</a>><br /> Content-Type: text/plain; charset="utf-8"<br /><br /> Hi List,<br /><br /> I'm putting together a 32 channel HDLA and looking for spatialization<br /> advice. The configuration will be two rings, one higher than the other,<br /> and I've been thinking a bit smaller/closer to approximate a hemisphere.<br /> But that's flexible - they could be parallel rings if it simplifies<br /> things.<br /><br /> I have some (limited) experience using HoaLibrary + PD for 2D ambisonics<br /> - so my initial thought was to try the 3d externals there - however I'm<br /> not sure if it actually makes sense to build an abstraction setup for a<br /> sphere of twice as many channels while limiting access to the upper<br /> hemisphere only. I'm assuming there would be some problems with that<br /> approach.<br /><br /> I found a few papers on mixed-order ambisonics - by Chris Travis and<br /> also the AmbiX crew - but I'm not sure if there's away to implement that<br /> stuff with HoaLibrary. I'm also open to using different software if<br /> something else is recommended instead.<br /><br /> Thanks for any advice!<br /><br /> -Jesse</blockquote>
</blockquote>
</div>
</blockquote>
</body></html>