Re: [LAU] Ambisonics: Which order fits my project?

On 7/5/20 1:31 AM, Michael Jarosch wrote: Hey, If I may add a few comments in addition to what Fons already wrote... :-) If Ambisonics is a good fit for you (read what Fons wrote) that would be my initial reaction... After you have your piece rendered in, say, 5th order, and if your rendering environment cannot do that (not enough speakers) then you just truncate to the order you can render (it should be the same except for the spatial resolution you obtain - caveat: the "feel" - sorry, very unscientific - of the piece might not be exactly the same precisely because the spatial resolution will be different). These days I would not generate content at less that 3rd order periphonic (16 channels). In my experience and in the context of concert reproduction and if you have enough speakers, it makes a big difference in localization accuracy and (specially) size of usable sweet spot. For example, a dome of 24 speakers (12 + 8 + 4) should give (pretty) good reproduction of 3rd order, but only (as Fons pointed out) if the spatial arrangement of the speakers is evenly spaced around the audience. In my experience f you have more speakers then 5th order sounds even better, more accurate and bigger sweet spot (we have a 56.8 space at CCRMA). I don't have personal experience with orders above 5th/6th, but apparently the advantages of going above 7th order are tiny or non-existent[*]. ... Having said that it would seem that it is always the case that higher order is better. Not necessarily... :-) While higher orders will give you pinpoint accuracy in sound placement in space if you are doing synthetic panning of mono sources, lower orders will give you more envelopment and diffuse sources, which might be important as well (those should be possible to achieve in higher orders but I don't think currently available software does that). I have been using mixed order for a while, two layers of 5th and 2nd order - I started experimenting with that because I am capturing 2nd order with microphones I built so that is a natural fit (spatially processing the output of the microphone). The 5th order layer adds very accurate positioning of sounds, and the combination sounds great - if I may say. Another quick test I did not long ago is 1st vs 3rd order rendering in binaural and for me 3rd sounds better (for my purposes). Caveat: I only tested using the Resonance binaural renderer. We are using 3rd order for our online concerts (the "Quarantine Sessions" series at CCRMA) where all performers are "panned" using Ambisonics. Hope this helps... -- Fernando [*] this has more concrete information about HOA: https://www.natashabarrett.org/Barrett_IRCAM_Report_v2.pdf [**] it is, as always, all up to the artistry and technical knowledge of the composer, I have heard 1st order pieces that are simply stunning - go no further than the Epiphanie Sequence pieces by Joe Anderson...