[SpHEAR-devel] F8 ambisonics mode

[Fernando Lopez-Lezcano]

(on a trip in Buenos Aires visiting family so short)...

On 10/16/2017 11:15 AM, Tim Maloney wrote:
>
> On Oct 12, 2017, at 12:00 PM, sphear-devel-request at ccrma.Stanford.EDU wrote:
>
>> It can record all four capsules (A-format) and monitor in stereo,
>> presumably doing an A-B conversion and stereo microphone rendering.
>
> Got it, installed it, tested it….
>
> But since I am in the middle of figuring out how to calibrate my *SpHEAR, I’m not sure how I would use it?  I’m assuming, as you are, that the filtering and combining stages are designed for already balanced and filtered signals coming into the F8.  So recording straight to B format would be a PROBLEM for me, yes?  I would want the separate signals as A format so that I can preprocess before converting to B…

This would be just for monitoring after you are done - or even before. 
If you record B format you will get something but it will be 
"sub-standard" as the conversion is not tuned for your microphone, just 
for the Ambeo and I don't know what kind of filtering they are doing. 
The Ambeo does not have per-microphone calibrations available, 
supposedly they are so good they don't need one (I don't quite buy that).

>> PS: just now starting to catch up after a LONG Summer long marathon
>> setting up a new 56.8 speaker array in our small concert hall, the
>> Stage, inaugural concerts last week (Wed/Thu).
>
> Now THAT sounds exciting!  What is the difference between your 64 channels and Atmos?  Or is it pretty much Atmos, just the DIY version?

Nothing to do with Atmos at all. Atmos is a proprietary system, 
completely closed and you have to buy their stuff to play or record or 
create. You can imagine that does not excite me :-)

This is used with other systems, you can either have direct access to 
all speakers and use whatever you want, or you can use HOA (High Order 
Ambisonics) with a built-in "perfectly" tuned decoder. It was (is) a 
complicated project for many reasons. We played pieces in 5th and 6th 
order full 3D Ambisonics for the concerts, and also other pieces that 
used speakers directly.

Best,
-- Fernando


> I was just up in SF this weekend for the Recombinant Festival - a friend was debuting her film in Naut Humon’s “Cinechamber,” which is a 10-screen 360 video installation.  We all got excited talking about the sound possibilities for this presentation.  Right now they are using 6 channels and it’s kind of wonky.  I’m pretty sure they’re calibrated with an SPL meter on site for the installation, but it seems that there’s no set way of creating and monitoring the sound before they set up the show.  I’m trying to think of ways to employ more of a soundfield approach for the space… Wish we could do 64 like you’re doing!
>
> Tim Maloney
> Professor, Department of Cinema and Television Arts
> California State University, Fullerton
> 657.278.2923  CP650-22
>
>
>
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