How to get audio unit instrument working with 16 stereo output channels?


I’m trying to get an AU (v2) synth working with zero inputs and 16 stereo outputs in Logic Pro 10.2.4
I am using the latest stable Juce 4.2.3.

I understand that for basic configurations filling out the Projucer channel configurations field should suffice - so no need to use the multibus api, right?

So I tried

{2,2}, {32,32}

{32, 32}

and a bunch of similar configs with 16 or 8 channels (in case 32 would not be accepted)


-only when there is a {0, 2} or {2, 2} config present does Logic allow to add the plugin to a track and then only as a Stereo version (it does not show a multichannel 16-stereo option)

-when I just use {0, 32}, or {32, 32} or {0, 16} or {0, 8}, etc., Logic does not show the plugin in its plugin picker UI. However it DOES show up in the Logic plugin manager and AU validation succeeds!

So my question is: am I doing something stupid here?
Is multichannel output supposed to work in a juce AU synth?
Should I perhaps use the 4.1 multibus apis instead of the Projucer field? (I did’nt as Fabian says they’re deprecated)


This is not true. You are using multiple output buses so you need to use the multibus API. Specifying {0,32} means you have a single output bus that has 32 channels.

Have a look at JUCE/examples/PluginSamples/MultiOutSynth to see how to do 16 stereo output channels correctly.


OK thanks, I’ll check out the sample


yay, got it to work with Audio Units!

One thing though: the aux bus names do not seem to be picked up by Logic. Are always called Aux 3…17. Same thing with the juce sample plugin

will the new multibus api support naming the aux buses in Logic?


Might be a limitation of Logic. If you run auval on your plugin then it correctly reports the bus names.