MXXX: Creating a plug that affects a track while using a bus that track outputs to as sidechain.

[Annabanna]

Yes, I am describing a form of feedback, but I want to be clear that I'm not talking about the internal feedback lanes within MXXX, but rather actual inter-channel feedback within the DAW.

I'm looking into creating a plug that does some of the following:

Channel A, and Channel B feed Bus 1.

Channel A has an instance of MXXX that uses Bus 1 as a sidechain input.

MXXX measures spectral and dynamic aspects of Bus 1, and applies inverse actions to Channel A.



If that's not clear, it's basically along the general lines of using a kick as a sidechain to MB compress a bass, but for this particular purpose, I have reasons to want to measure the combined output (kick and bus in this example) rather than simply the kick as the sidechain.

I'm wondering whether any folks that have done anything along these lines have noticed any issues relating to the concept that there is essentially a partial feedback loop. (Partial meaning the feedback exists only in the sidechain signal, and not in the audio directly).

Anyway, I've done something along these lines before with other plugs. Logic seemed to have a problem with it sometimes, but not others, though it was a while ago, and I don't remember any particular differentiating factor as to why it sometimes had issues.

Anyone got experience with this concept that's noticed anything interesting or noteworthy? Particular things I should pay attention to? Lookahead issues, for instance? Are any issues DAW specific? Any particular MXXX features I should make sure to have enabled or disabled to avoid issues?

[MeldaProduction]

What you ask is impossible I'm afraid. If you cannot sidechain something, it's because it would defy laws of physics. And if a plugin would attempt to do that, it would freeze. MXXX's feedback system gets around it using some subgranularization (but I think it only solves one thing, as I feel like you are talking about 2 things at the same time).

[Annabanna]

Oddly (In Logic, at least), I have gotten it to work a few times. Again, though, just talking about feedback via sidecahin... not the audio track itself.

It's an unusual use case for sure, but it allows for some unique sidechain analysis... just wondering if anyone had done it with MXXX and noticed anything worth mentioning. I wouldn't assume many people have tried.

[MeldaProduction]

I don't think that's possible, maybe it seems like you did despite you didn't, but who knows. It would be especially surprising in Logic. Anyways most hosts allow only forward audio sending, hence avoiding any feedback. Both for physical reasons and to avoid the potential freeze.

[Annabanna]

That's why I said "a few times". It has also caused freezes as you predicted. I was just never exactly clear why it worked sometimes and not others... and whether that depended at all upon the plug being used.

EDIT: Honestly, I didn't expect to stumble across anyone using MXXX this way, but thought I'd check just in case since I'm doing something generally along those lines.