I'm fairly sure I have seen this a couple of times with the PC Concrete limiter.  It probably had to do with settings getting lost, because removing the CL and adding it back in cleared the problem.

I am seeing this issue, together with a loud POP, peaked VU meters and audio engine who will only output DC. Here´s my first thread on the subject:
 
http://forum.cakewalk.com...-m3374594.aspx#3377356

That describes the problem I see very well. It continues to happen randomly. I don't have a Babyface - I use a Scarlett 8i6. I suspect the combination of Ozone and Sonar. Every project it happens in has Ozone on the Master Bus. Can be versions 5 through to 7, 32 or 64 bit.
 
Do you use Ozone in the projects where the problem occurs?
 

No, I´ve never used Ozone.I might add that this problem used to be more random but now it´s a little bit more predictable: it almost always starts after an audio export, then it´s downhill from there.
 
Today, I tried to disable most plugins to find out the culprit but I didn´t really get that far. My findings so far:
 
* Disable all FX (using the FX button): worked fine, totally cures the problem.
* Disable known "problem plugins" (channel tools, VC64): No difference, really.
* Disable all Prochannel strips: Does improve things a lot! It´s still there but cycling the audio engine one or two times reverts it back to working state.
 
During my experiments, I realized that by disabling & enabling the FX using the FX button, I always managed to get the audio engine back online when it´s stuck at 9dB. Sonar also seems to be able to run longer without any problems by doing so the problem is not so much of a showstopper now as it used to be.
 
 
 
 

PeterMc
That describes the problem I see very well. It continues to happen randomly. I don't have a Babyface - I use a Scarlett 8i6. I suspect the combination of Ozone and Sonar. Every project it happens in has Ozone on the Master Bus. Can be versions 5 through to 7, 32 or 64 bit.
 
Do you use Ozone in the projects where the problem occurs?
 

OK, so it looks like this is not plugin specific. I also find that turning off all FX using the FX button stops the meters maxing out, but hitting the FX button again sometimes restarts the problem.
 
Do you observe the problem when the transport is stopped but audio engine is running? I do.
 
I now suspect some sort of coding feedback loop related to the FX bins.

Yes, I do see the problem even when the project transport is stopped.
 
 

PeterMc
OK, so it looks like this is not plugin specific. I also find that turning off all FX using the FX button stops the meters maxing out, but hitting the FX button again sometimes restarts the problem.
 
Do you observe the problem when the transport is stopped but audio engine is running? I do.
 
I now suspect some sort of coding feedback loop related to the FX bins.

Engineering Effects Suite 1.0.0.13 had fixes for this.  Have you upgraded your Channel Tools and VC64?  Seems that there was also a fix to Concrete Limiter at about the same time for this problem
 
Glen

According to Command Center, everything is updated to the latest version. I don´t Channel Tools is the culprit since I removed them and the problem is still there.
 
However, I´m using plenty of effects in a current project and I´m thinking of disabling them one by one while documenting everything. Hopefully, that will give some more information about the problem.
 

gcolbert
Engineering Effects Suite 1.0.0.13 had fixes for this.  Have you upgraded your Channel Tools and VC64?  Seems that there was also a fix to Concrete Limiter at about the same time for this problem
 
Glen