Spat5 VBAP Reference Position Error

#1

Hi,
I’m trying to test an unusual speaker configuration using VBAP but get the following error message:

spat5.spat~: error occurred when processing “/speakers/aed -45 12.3639 1.44779 45 12.3639 1.44779 58.7363 0 1.63783 75.9638 0 2.06155 48.1798 0 1.27475 -48.1798 0 1.27475 -75.9638 0 2.06155 -58.7363 0 1.63783”. Reason: invalid setup for vbap : the reference position must be inside the speaker setup.

I have set the reference point as xyz 0 0 0, which i think is ‘inside’ the setup, but not sure what the issue is. I’m trying to use vbap3d because the first two speakers are 2.6m higher than the other 6 speakers, which are on a 2d plane. I just want to be able to make some simple up/down source movements between the top and bottom stage pairs, otherwise I would use angular panning (not sure if angular panning works in 3D).

The 8 speaker positions are:
/speakers/xyz -1 1 0.31 1 1 0.31 1.4 0.85 0 2 0.5 0 0.95 0.85 0 -0.95 0.85 0 -2 0.5 0 -1.4 0.85 0

Thanks for any advice / tips.

#2

Hi,

As a matter of fact, the reference point (0,0,0) is NOT inside the speaker setup.
You would need to shift the array, for instance :
/speakers/xyz -1 0.212598 0.31 1 0.212598 0.31 1.4 0.062599 0 2 -0.287402 0 0.95 0.062599 0 -0.95 0.062599 0 -2 -0.287402 0 -1.4 0.062599 0

Yet, the layout is kind of ill-suited; depending on the source location, I expect the panning law to not be very smooth.
Maybe LBAP or KNN might work better – depends on what you want to achieve.

Angular panning doesn’t work in 3D.

Best,
T.

#3

Thanks for clarifying T. I’ll try LBAP or KNN as you suggest.
N