Thanks for the detailed reply, Archontis! Good feedback for us. Yes, sorry, I did kind of group all of my responses to various comments in this thread into one reply.
Keep an eye out for an update to our encoder plugin (including 4th order, in approximately the same range you mention). Everything is working in the lab here; just need to find time to package, document, and post to the website. Looking forward to seeing how your Web Audio project evolves. My wife is always telling me to stop writing native apps in archaic C++, and that the web is the future. Guess we have arrived! -Steven > On Jun 22, 2016, at 12:56 AM, Politis Archontis <archontis.poli...@aalto.fi> > wrote: > > (Sorry for the re-posting, sursound seems to destroy indentation from my mail > manager, making the previous one hard to read..) > > Hi Steven, > > There seems to be a misunderstanding, your seem to address the considerations > raised by Stefan here on the list , not me :-) … > > I am quite a fun of the microphone and I have gotten excellent results > rendering to large loudspeaker arrays (>25ch) using both ambisonic decoders > and the parametric decoders that we are developing here in Aalto University. > >> On 22 Jun 2016, at 00:31, Steven Backer >> <s...@mhacoustics.com<mailto:s...@mhacoustics.com>> wrote: > >> Nice work! It’s great someone is taking the time to put together the >> infrastructure for web-based ambisonics. >> I enjoyed watching your Intensity Analyzer. > Thanks a lot! The intensity analyser it’s a bit incomplete at the moment, > cause it’s showing the broadband intensity vector, so it’s hard to show > multiple different sources from different directions. I’ll soon add a > band-passed version. > >> How did you encode the raw Eigenmike signals? >> Using some of our software (EigenUnits-Encoder or EigenStudio), or something >> else? > All the examples use the Encoder plugin provided by you. We have created our > own encoding filters too here, based on dense anechoic measurements of the > EM, which get some decent 4th-order components with a range of 2kHz~7kHz, but > they lack some bass on orders 2&3 compared to your Encoder (I guess you’re > using a thresholding approach at LF?) > >> In fact, we’ve found that some decoders, specifically for HOA, do present >> some challenges that can degrade parts of the spatial image and spectral >> response. >> There will be a paper presented on this topic at the upcoming AES Sound >> Field Control conference in Guildford. > This is an interesting point you raise cause ambisonic research itself has > avoided it pretty much. I think because it breaks the useful separation > between microphone encoding and loudspeaker decoding. Hence, decoding becomes > frequency-dependent with respect to the array size, mics etc. We have used > both an order-limited approach here (a n-th order decoding matrix per band > that the EM delivers properly the n-th order signals), and a decoding filter > matrix approach. But we have gotten good results one way or another so I know > that EM can deliver :-). > >> In the past, we had control of both ends of the signal chain (i.e. the >> beamforming in EigenStudio), and we could “do the right thing”. >> Now without knowing a-priori what the decoder is doing it becomes more >> difficult. This could explain some of the effects discussed earlier in this >> thread. >> We will soon be releasing some software updates that will hopefully address >> some of these issues. So perhaps reserve some judgement for a later date ;-) > That sounds great! (and no judgment from my side..) > >>> An Eigenmike has some aliasing limit frequency >> You are correct that the Eigenbeams will spatially alias around ~8kHz. >> We do implement a workaround for traditional beamforming, but for ambisonics >> applications we just let it alias. >> There is still usable signal up to (temporal) Nyquist and I’ve heard plenty >> of material that sounds just fine up there. > Let aliasing above that HF is reasonable. Another approach that may improve > slightly compared to that, and something we have used in the past for > parametric decoding, is to point your alias-suppression HF-beamformers > towards the speakers. > >>> The eigenmike could be a nice tool for VR/AR recordings >> Absolutely! We think so, too. >> We’ve actually been pretty busy recently making quite a few recordings (some >> with video!), and have some great material we are going to share publicly >> very soon. > Please do! The 3-4 recordings you have at the moment on the website do not do > justice to the EM potential! > > Best regards, > Archontis Politis > -------------- next part -------------- > An HTML attachment was scrubbed... > URL: > <https://mail.music.vt.edu/mailman/private/sursound/attachments/20160622/f94be3f4/attachment.html > > <https://mail.music.vt.edu/mailman/private/sursound/attachments/20160622/f94be3f4/attachment.html>> > _______________________________________________ > Sursound mailing list > Sursound@music.vt.edu <mailto:Sursound@music.vt.edu> > https://mail.music.vt.edu/mailman/listinfo/sursound > <https://mail.music.vt.edu/mailman/listinfo/sursound> - unsubscribe here, > edit account or options, view archives and so on. -------------- next part -------------- An HTML attachment was scrubbed... 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