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Spat5.spat~ vbap3d

I try to use spat5.spat~ and use vbap3d, but there will be many errors in the max console, and I have no idea how to solve it.


These are warning messages, not errors.

The vbap3d algorithm splits the speaker setup into triangles (a.k.a. triplets).
The warning messages tell you that some of the triplets in your setup are “poorly balanced”.
This might be a sign that your speaker layout is ill-suited for vbap. As suggested, inserting a so-called “phantom speaker” might mitigate this issue.

Have a look at spat5.pan~.maxhelp (vbap tab) and spat5.tuto-phantom-1.maxpat for further details.
You can also post your speaker coordinates here.


Hi tcarpent,

I use the speaker layout coordinates of c-lab Taipei. At first, I used HOA. Recently I want to try the surrounding effect of vbap3d.
I tried to use the “phantom speaker”, but it seems that the warning message still exists.

Below is my max patch.
clab_vbap.maxpat (54.9 KB)



Below are some 3D views of the vbap triplets (without phantom speakers).

Indeed, some of the triplets are ‘poorly’ oriented or have a smallish surface, as indicated by the warning messages. This means that panning might not be very smooth if you move a virtual source close to these triplets (I think it’s mostly on the lateral side of the room).
Adding phantom speaker would not really help in your case (yet, adding a phantom at nadir would not hurt).
So, VBAP rendering might not be perfect (for this speaker setup), but it’s worth trying it.