Hi Joseph. I am thinking of hacking the emotiva UMC-200, if I use the secondary zone DACs I should be able to get some reasonable quality out of it.
Regards Alexis Shaw On Tuesday, December 17, 2013, Joseph Anderson wrote: > Hello Alexis, > > Sounds like a fun project. What is the hardware you're hacking? > > > My best, > > > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > Joseph Anderson > > j.ander...@ambisonictoolkit.net <javascript:;> > http://www.ambisonictoolkit.net > ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > > > > On 16 Dec 2013, at 3:13 pm, Alexis Shaw <alexis.s...@gmail.com<javascript:;>> > wrote: > > > Hi Joseph > > > > In terms of decoder I was intending to hack a hifi preamp with an 8 > > input-12output matrix 128k long fir filters. That is DFT the inputs, for > > each frequency in that fft multiply by a matrix, then do an IDFT on the > > output. > > > > Of course you do something a little more complicated in order to fix up > > latency problems. > > > > This, I think is the most general Ambisonic decoder that is possible at > the > > moment. And if you play with the coefficients you can also do room > > correction, delay lines all in that framework. > > > > On Tuesday, December 17, 2013, Joseph Anderson wrote: > > > >> Hello Alexis, > >> > >> A few things.... > >> > >> A) How were you planning on running your decoder? Write code from the > >> ground up? Build your own hardware? > >> > >> If you're looking for something somewhat between 'off the shelf' and > 'grow > >> your own', you may like to have a look at the Ambisonic Toolkit package > for > >> SuperCollider. From the web page, "SuperCollider is a programming > language > >> for real time audio synthesis and algorithmic composition." > >> > >> The new and the older pages are here: > >> > >> http://supercollider.github.io/ > >> http://supercollider.sourceforge.net/ > >> > >> > >> The page for the Ambisonic Toolkit is here: > >> > >> http://www.ambisonictoolkit.net > >> > >> > >> B) On your decoder arrangement... I'd suggest you think about the > >> bi-rectangle arrangement, which uses 8 loudspeakers. This can work well > in > >> a domestic situation. Four loudspeakers are placed in the horizontal > plane > >> (in a rectangle), and then two more on the ceiling and two on the floor. > >> Imagine two planes bisecting each other: one horizontal and one > vertical. > >> > >> The ATK has a wide variety of inbuilt decoders. This page lists them: > >> > >> http://doc.sccode.org/Classes/FoaDecoderMatrix.html > >> > >> For a bi-rectangle, you'd use the diametric decoder. For two hexagons, > >> you'd use the periphonic decoder. The ATK also includes Near Field > >> Compensation and Psychoacoustic Shelf Filtering, allowing you to > implement > >> classic, optimised decoders. Additionally, because SuperCollider is a > >> programming language for audio synthesis and signal processing, you also > >> get delay lines and multipliers (gain adjustment) to compensate for > >> differences in loudspeaker distances. > >> > >> > >> Hope this helps!! > >> > >> > >> My best, > >> > >> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > >> Joseph Anderson > >> > >> j.ander...@ambisonictoolkit.net <javascript:;> <javascript:;> > >> http://www.ambisonictoolkit.net > >> ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ > >> > >> > >> > >> On 16 Dec 2013, at 1:25 am, Alexis Shaw > >> <alexis.s...@gmail.com<javascript:;> > <javascript:;>> > >> wrote: > >> > >>> Hello All > >>> > >>> I am a long time lurker here, and have been interested in setting up an > >>> ambisonic listening room in my house for some time. I have finally got > >> the > >>> courage to try, however the only room that I have available to use is > >>> multi-use and only of moderate size 20m^2 (3940*4750*2690mm) In order > to > >> be > >>> able to make the most of the space I have been thinking about using > >>> moderately high end in-wall and in ceiling speakers in an rectangular > >>> double-hexagon arrangement. > >>> > >>> My question here is two fold: > >>> 1 - Do you think that this is at all a good or interesting setup. Even > >> with > >>> lots of work. I have a moderate undergraduate level of understanding of > >> DSP > >>> and and have read almost everything that I can get my hands upon about > >> both > >>> spherical harmonics and ambisonics and so feel able to write a custom > >>> decoder if I have to. > >>> > >>> 2 - If the answer to the first question is yes, do you think that the > >>> Noble-Fidelity L-85 LRCS (in ceiling) and L-82 (in wall lowers) would > be > >> an > >>> appropriate speaker for this purpose. If not what speaker would you > >>> recomend (if any). I am not attached to these speakers however I cannot > >>> afford much more than USD 300 for each speaker. > >>> -------------- next part -------------- > >>> An HTML attachment was scrubbed... > >>> URL: < > >> > https://mail.music.vt.edu/mailman/private/sursound/attachments/20131216/8a2b9c8d/attachment.html > >>> > >>> _______________________________________________ > >>> Sursound mailing list > >>> Sursound@music.vt.edu <javascript:;> <javascript:;> > >>> https://mail.music.vt.edu/mailman/listinfo/sursound > >> > >> -------------- next part -------------- > >> An HTML attachment was scrubbed... > >> URL: < > >> > https://mail.music.vt.edu/mailman/private/sursound/attachments/20131216/2485a933/attachment.html > >>> > >> _______________________________________________ > >> Sursound mailing list > >> Sursound@music.vt.edu <javascript:;> <javascript:;> > >> https://mail.music.vt.edu/mailman/listinfo/sursound > >> > > -------------- next part -------------- > > An HTML attachment was scrubbed... > > URL: < > https://mail.music.vt.edu/mailman/private/sursound/attachments/20131217/f2349c8a/attachment.html > > > > _______________________________________________ > > Sursound mailing list > > Sursound@music.vt.edu <javascript:;> > > https://mail.music.vt.edu/mailman/listinfo/sursound > > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: < > https://mail.music.vt.edu/mailman/private/sursound/attachments/20131216/3eb5a8f6/attachment.html > > > _______________________________________________ > Sursound mailing list > Sursound@music.vt.edu <javascript:;> > https://mail.music.vt.edu/mailman/listinfo/sursound > -------------- next part -------------- An HTML attachment was scrubbed... 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