Thanks Archontis, that is very useful. I'll try that, it seems to corroborate what I had in mind initially. What's the worse that can happen, right? :)
Thanks for the help! - martin On 9 February 2016 at 22:34, Politis Archontis <[email protected]> wrote: > Hi Martin, > > HOA are not limited to icosahedra or only uniform arrangements (which exist > also beyond the 5 platonic solids). It would be very hard to claim them > flexible or universal if that was the case. Uniform arrangements though > simplify decoder design significantly. > > As I mentioned you would need some more recent decoder methods for a > hemisphere, however these methods are available and not so sensitive to > speaker placement (no need for quests for magical geometries). My two cents, > start with a regular horizontal ring, covering the case of horizontal > decoding too, and spread the rest of the speakers evenly at the hemisphere, > covering roughly equal area partitions. You can also fix one straight above > and work with the rest. I believe the system should be capable of decoding > 3rd order signals to half-space for such an arrangement, but that needs some > checking. > > I mentioned two publicly available resources for decoding to such a setup. I > forgot to mention however that there exist also professional tools for that. > I think Blue Ripple Sound’s decoder can handle hemispheres and irregular > setups (haven’t tried it myself) and also the latest Spat from IRCAM has > implemented the more advanced HOA decoders I mentioned. > > Best, > Archontis > >> On 10 Feb 2016, at 00:16, Martin Dupras <[email protected]> wrote: >> >> I have no objection to using fewer than 16 speakers; it's just the >> maximum I have available to me. >> >> The reason I had not considered the icosahedron vertices setup is >> because, according to the wikipedia page, it's capable of 2nd order, >> not 3rd order. Is that not the case? >> >> Again from wikipedia: "Since stacked rings are somewhat wasteful at >> higher elevations and necessarily have a hole at the zenith, they have >> been largely surpassed by hemispherical layouts since mature methods >> for decoder generation have become available. As they are difficult to >> rig and require overhead points, hemispheres are usually found either >> in permanent installations or experimental studios, where expensive >> and visually intrusive trussing is not an issue." >> >> That's the whole reason why I was considering a hemispherical setup >> originally. It talks about "mature methods for decoder generation" so >> I (wrongly, perhaps) assumed that there were capable decoders, and >> there would likely be already available "templates" or "typical >> scenarios" to use as a starting point. >> >> Thanks, >> >> - martin >> >> >> - martin >> >> On 9 February 2016 at 22:02, Augustine Leudar <[email protected]> >> wrote: >>> I know Im treading on thin ice here around all these ferocious maths >>> guys... but might it be that there is not a suitable array that uses 16 >>> speakers? I know if you have 16 speakers you will want to use all of them >>> but an Icosahedron is only 12 speakers (vertices) but it might be the best >>> option. >>> Also you could try ICST ambisonics plugins in max - they let you put the >>> speaker array in and it adjusts accordingly. >>> >>> On 9 February 2016 at 21:51, Martin Dupras <[email protected]> wrote: >>> >>>> Thanks for all the responses. Much appreciated. >>>> >>>> I'll re-phrase the question in light of some of the answers I've been >>>> given. >>>> >>>> I will be using third-order Ambisonics. My aim mostly is to experiment >>>> to get a good sense of what is possible with Ambisonics with height. I >>>> have experimented successfully with 8-channel planar Ambisonics some >>>> time ago. My primary intent is to spatialise multiple monophonic >>>> (synthesised) sources using 3rd-order Ambisonics spatialisation, and >>>> the playback of mixed sources (spatialised monphonic and stereophonic >>>> sources as well as B-format 4-channel recordings.) >>>> >>>> At this moment in time, I have the opportunity to deploy (next week) a >>>> 16-channel array, so I would like some advice on a configuration that >>>> would be a good start to experiment with Ambisonics with height. >>>> Someone suggested that I consult the wikipedia page on Ambisonics. >>>> That is indeed where I got the idea that an "upper hemisphere" setup >>>> might be suitable, since I only have on this occasion 16 speakers. >>>> There is however no suggestion as to what a suitable hemispherical >>>> configuration might be for a 16-speaker array, which is why I asked my >>>> original question. >>>> >>>> So let me ask a new question. Given the constraint that I can only use >>>> 16 speakers at the moment, and that I need to deploy this next week, >>>> can somehow point me in the direction of what might be a suitable and >>>> reasonable geometric configuration to try out? It seems to me that the >>>> only really practical options here are two stacked rings (stacked >>>> octagons) or a hemisphere. I would have thought that the hemisphere >>>> would be the better choice, and in my scenario, a full lighting rig >>>> allows me theoretically speaking to have speakers at the required >>>> positions. >>>> >>>> Again, thank you for all the responses. >>>> >>>> - martin >>>> >>>> >>>> On 8 February 2016 at 15:19, Martin Dupras <[email protected]> wrote: >>>>> Hi, >>>>> >>>>> I'm intending to try setting up a 16-speaker Ambisonics array next >>>>> week in a small TV studio. I'm trying to figure out the practical >>>>> arrangements for setting up the speakers. I was wondering if anyone >>>>> with experience might be able to offer some advice or point me in the >>>>> right direction? >>>>> >>>>> What I'm planning at the moment is a half-sphere arrangement which >>>>> would likely consist of: >>>>> >>>>> - 8 speakers in a circle of radius 2m at a height of approximately 1.6m >>>>> - 6 speakers in a smaller circle at an elevation of 45 degrees >>>>> - 2 speakers at an elevation of approximately 75 degrees >>>>> >>>>> Alternatively, I would be happy with an arrangement similar to the >>>>> first 16-speakers in this diagramme: >>>>> >>>> http://www.matthiaskronlachner.com/wp-content/uploads/2013/10/loudspeaker-plan-observatory.jpg >>>>> >>>>> I've been trying to find out if there is a convention or "most usual" >>>>> arrangement but couldn't find anything. I'm not particularly attached >>>>> to the actual arrangement, I just want to find an arrangement that >>>>> will work well enough with 16 speakers. Any advice? >>>>> >>>>> The other thing I would welcome is advice on how to mount the speakers >>>>> to lighting rigs in a manner that is practical enough to offer some >>>>> good compromise between precision and ease of setup. I believe the >>>>> speakers we'll be using for the upper tiers will be Genelec 8060s. >>>>> >>>>> Many thanks. Any advice will be greatly appreciated! >>>>> >>>>> Cheers, >>>>> >>>>> - martin >>>> _______________________________________________ >>>> Sursound mailing list >>>> [email protected] >>>> https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here, >>>> edit account or options, view archives and so on. >>>> >>> >>> >>> >>> -- >>> www.augustineleudar.com >>> -------------- next part -------------- >>> An HTML attachment was scrubbed... >>> URL: >>> <https://mail.music.vt.edu/mailman/private/sursound/attachments/20160209/6d5ca824/attachment.html> >>> _______________________________________________ >>> Sursound mailing list >>> [email protected] >>> https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here, >>> edit account or options, view archives and so on. >> _______________________________________________ >> Sursound mailing list >> [email protected] >> https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here, edit >> account or options, view archives and so on. > > _______________________________________________ > Sursound mailing list > [email protected] > https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here, edit > account or options, view archives and so on. _______________________________________________ Sursound mailing list [email protected] https://mail.music.vt.edu/mailman/listinfo/sursound - unsubscribe here, edit account or options, view archives and so on.
