Pro Compressor side chain bug

[yoerik roevens]

Originally Posted by Reckless Erik

Just to clear things up a bit. When the send on the trigger track is deactivated the problems occur. If you create an empty track below with an active send it makes no difference.Attachment 8494

That's even weirder, although my guess is protools is not expecting any signal to the sc bus in this scenario either. What happens if you put a silent (not muted) -region on the second (C) track?
Also, do you have 'dynamic plug-in processing' enabled? Does it help if you disable that? (my guess is that without dynamic plug-in processing, protools will not deactivate anything when it 'assumes' there is no signal to be expected)

[Reckless Erik]

Placing a blank region/clip on the C track makes no difference. Neither does dynamic plugin processing. The reason I discovered this was by accident. I was printing some stems and the duck bus was deactivated. To my horror the stems were compressing when of course they should have been clean. Not what I wanted!

[Stig Eliassen]

Originally Posted by yoerik roevens

Exactly, so it seems busses get de-activated when they have no input signal assigned to them. Makes sense, bu the pro compressor shouldn`t compress when there`s no active signal routed to it's SC input indeed.

So the OP is absolutely right. This behavior is incorrect.

No, that is not what I meant. The bus is active (how else would a second track/send feeding the SC have any effect?), but deactivating the source feeding the SC input of a compressor is equivalent to NO SC input.

[Reckless Erik]

...deactivating the source feeding the SC input of a compressor is equivalent to NO SC input.

As I said before, it's not the source that is de-activated but the send on that source track and if what you say above is true then why is the compressor reacting to the input signal and not to the SC signal?

[dwaynedelario]

I believe I have seen the same behavior in Fabfilter's Pro-C2. If you assign a bus as the key input, the compressor will not see the sidechain until that bus is actively engaged in the session i.e. that bus needs to be active on a send or output for the plugin to recognize it. If you just use a random bus from your I/O that isn't used, it won't see the key input.

[Stig Eliassen]

This is what you guys are seeing, right?

https://www.dropbox.com/s/xo3dmpdm5q...31.42.jpg?dl=0

https://www.dropbox.com/s/zc599tlyd4...31.28.jpg?dl=0

https://www.dropbox.com/s/qwlcxufdfr...31.17.jpg?dl=0

[Reckless Erik]

This appears correct. My gripe is why the compressor is active when the side chain effectively sees no signal when the trigger bus is inactive.

[Stig Eliassen]

Originally Posted by Reckless Erik

This appears correct. My gripe is why the compressor is active when the side chain effectively sees no signal when the trigger bus is inactive.

Gotcha. This scenario makes sense to me, but as said, I don't know if this is intended behavior. Inactive sends feeding the SC bus = "pulled plug" (in lack of a better analogy) = normal compression.

[Reckless Erik]

Hear you. As I am a remnant from the days of mixing consoles and patch bays I feel that disabling a bus/send is analogous to yanking out the patch cord that feeds the s/c on the outboard processor!

[czarnekci]

Hello!
I had the same "issue", and I would like to jump that up because it feels really unnatural to me that when no SC bus are active, then the plug-in get back to the input feed of the plug-in.

It's even more strange on fabfilter C-1 because that plug-in has an "IN/EXT" switch.... and even if it is locked to EXT, it behaves as IN if the bus on protools are not active on any track.

It took some time to me to understand what was happening as it was for a VoiceOver dubbing session, so the SC and input are almost at the same time.