JuceDemoPlugin mono only in Live?


When I insert the JuceDemoPlugin in Ableton Live, it make everything mono…
I admit, I’m not familiar with Live, but it looks to me as it’s not recognizing properly the channels ?

Or I am missing something ?



Hi Again,

Definitively there’s only 1 channel (left) that is used by the juce plugin.
Jules ?


AU or VST? It sounds more likely that Ableton is deciding to use only one channel of the plugin… I don’t know anything about Live either, but maybe you’ve got a mono channel or something?

That would have been fun :mrgreen:

So when I just try juceDemoPlugin, AU works fine in stereo, but VST collapse my track to mono.
In the process blcok, it still repport :
getNumInputChannels = 2
buffer.getNumChannels() = 2
getNumOutputChannels = 2

Though it’s mono at output.


Weird… I’ve really no idea about that. If it’s giving the plugin a stereo signal, then I’m stumped as to why it’d monoise it later…

It looks like both channels are processing properly, but it’s actually summing both inputs channels to mono at the output…


No idea then! Can’t be anything that the plugin’s doing, can it?

That’s the juceDemoPlugin, I didn’t changed any processing inside…
And the AU works normally.

I can’t beleive I’m alone having the problem ? Am I ?


No you are not the only one, we have the same problem with Live.

Well the demo plugin returns false for isOutputChannelStereoPair() - maybe that’s what’s confusing Live? (I should probably change that anyway, TBH, I don’t know why I set it to false)


Works now if both isInputChannelStereoPair & isOutputChannelStereoPair are set to true.
Thanks for the hint !

I guess setting those to true won’t cause a problem for mono insert or in other hosts ?


Depends what your plugin actually does - if it’s stereo, then set them to true. If all your channels should be treated as distinct, then returning false is the correct thing to do, and if Live fails to use all the channels, then I’d say that’s a bug in Live.

That’s the way live works (in every version I’ve tested). It only supports stereo channels. If your layout is mono, live will convert it to a stereo channel - it will copy your mono channel. If you don’t specify your channels as stereo pair for VSTs, live will assume that the first channel is a mono channel and so it will duplicate it, to create a stereo version of it.
I don’t like the way live is doing this, but this is no bug, but the design of lives’ routing and it did that in every previous version. If you specify your layout correctly, you shouldn’t have any problems with live or other hosts.