Getting a slight bleed on mono track panned L or R

[macmuse]

Hi, I noticed that when I solo a mono track which is panned either 100% left or right, I am still getting a slight bleed into the other channel. Is there something I have inadvertently overlooked that would cause this? It seems to be happening only in this one session, but rather than recreate in entirety into a new session, I wanted to know what would be a possible culprit that I could look for here.

Otherwise, I did inspect my I/O and there is nothing out of the ordinary there. I started the project with auxes for guitars, etc. with routing, but when I noticed the bleed, I eliminated them and now send everything to the stereo master (which is analog 1+2 as on my audio interface) but still get the bleed. So maybe something got corrupted?

Thank you!

[JFreak]

The bleed most likely happens on your analog cabling.

But if you suspect there is something going on within PT mixer, here is how you can rule it out:

- create a mono channel and route it to your stereo mains
- insert signal generator to the mono channel
- pan mono channel to hard left
- bounce and import

If there is a problem, your bounce would show something else than silence on right channel. If it is silent, whatever bleeding you may hear happens after DA conversion.

[daeron80]

M/S processing? Analog modeled plugins? Chorus with cross-modulation?

[JFreak]

Whatever is panned hard left should be hard left. If there is bleeding there are only two possible causes: the digital side or the analog side of things. I already gave advise to test that digital side of things is alright, and after that is ruled out the culprit is either on the analog side or sub-par DA converter.

[macmuse]

Thank you! It seems to be just this one project having the issue. I did check the physical cabling which is OK because the L/R pans properly with no bleed in Logic, Cubase, and also in PT in other PT projects. I use an RME Fireface 800.

I'm not using M/S or analog plugins in this instance. It just seems that somewhere along the line here something became wrong in my setup in this session only, but I can't seem to find what it is because it looks OK. I do notice in sessions though that some old buses from other projects show up in other projects, but sometimes not. Are the setups universal or per-session only, and can that be specified?

Somehow I think it has to do with residual changes of some sort, because I started the session with buses/auxes, then removed them, then changed to routing folders, and then routing directly to the master. Usually I leave it all be, but after the first change or so I started noticing this bleed issue which then made me change the routing further. Can I trash the preferences just for this one session? If so, I would like to do that.

[Kasper]

Maybe you have an AUX somewhere that is solo safe?

Back up your session and i/o settings.

Create a new session.
Default all your i/o settings.
Test your pan in the new session.

kasper

[Kasper]

Also, might check your divergence, if it's a surround session.

[macmuse]

OK traced it to an instance of MasterDesk on the master. It must stereo-ize a mono soloed signal, which is interesting, because other master bus plugins (Ozone, Mixdown, compressors, etc) never did that. This is the first I've encountered this behavior which was making me scratch my head.

[JFreak]

Some plugins do what you want them to do, some others work otherwise.

[its2loud]

Originally Posted by daeron80

M/S processing? Analog modeled plugins? Chorus with cross-modulation?

This was the correct response to the OP.
MasterDesk has a stereo widening, M/S feature which would absolutely make a mono, hard panned, signal bleed into the other channel.