MP 1,1-5,1 OCLP 2.3.2 Monterey CoreAudio Issue

[MacintoshDude24]

Hi, I've had OCLP 1.5 running BS and now Monterey on my MP 5,1 but I'm having major problems with both Apple Core Audio and any Firewire audio connections. The result being worst case, constant digital distortion or best case, glitchy audio. Normally after a few restarts, the audio would be fine. Now after updating to OCLP 2.3.2, no matter how many restarts, when I launch QT or any Audio App like Cubase, there is immediate digital distortion/feedback. I should add this happens whether the RME FireFace FW 800 is connected or not which leads to the conclusion, there is an issue with the core audio.
I've checked the extensions in ~/Users/Library/Extensions and there is a FirefaceAudio.kext but there isn't one for either AppleFWAudio or AppleCoreAudio. I assume these are somewhere in the OCLP EFI?

I've checked the RME forums just in case there is a FW conflict with OCLP but as the issue persists whether the FF800 is in the loop or not, I feel the problem lies with OCLP and AppleCoreAudio. Should add, I've tried to post on the relevant Discord channel but as of yet, I don't have permission to post.

Would be grateful if anyone here could assist and or point me in the right direction.

Thanks,

McD

 

[reader50]

Have you tried swapping a few FW cables? Try daisy-chaining off a different port? Check output cable?

I replaced a surround-sound receiver once, only to discover it was a glitching optical audio cable. Old receiver was still good. One new toslink cable later, and I had two working receivers.

 

[MacintoshDude24]

I did try different cables but with same result. Tomorrow I'm going to try it on another Mac running the same OCLP install and see what occurs. If on the other setup, even the core audio has the same problem, then it does point to OCLP being the issue. Should also mention there are no post install drivers flagged so as far as OCLP is concerned, it's installed everything that is required.

 

[reader50]

Do you still have a bootable copy of Mojave or Catalina available? A macOS version that will direct-boot your 5,1 without OCLP involved at all. To see if audio output stabilizes, which would confirm it's an OCLP (or late-macOS) problem.

I've found that Big Sur needs OCLP to install on my 4,1->5,1 but can be direct-booted after install. Not sure if Monterey will do that. However, these are still macOS versions with patched drivers from OCLP, so OCLP would not be completely out of the test loop.

Also, have you tried a different output channel, like the internal speaker? To eliminate your output device as a suspect.

 

[MacintoshDude24]

Hi Reader, can confirm issue doesn't happen with native os for the MP 5,1. It only happened once OCLP was used to go up to BS and beyond. As for the internal speaker, it's the same under OCLP so indicates something is getting messed up with the patching?

 

[reader50]

Suggest doing a retest of an older OS in the present - don't rely on how it behaved in the past. Something has changed, and that something could be a port becoming loose or some other hardware glitch developing. It's best to eliminate the other possible causes before convicting OCLP. Testing on another Mac Pro is another good check.

From what I've heard, it's difficult to give feedback to the OCLP developers. Easier to narrow down the suspect list before climbing that hill. Especially if it turned out not to be OCLP.

 

[MacintoshDude24]

That is a fair comment, innocent till proven faulty. Will try and post outcome.

 

[reader50]

Another suspect to consider. I've upgraded many times since Snow Leopard, and to some extent, even my current Sequoia install was inherited that far back. I have used Migration Assistant a few times, but always brought everything forward. Not just user accounts and Apps.

Several times, I've had issues that traced to keeping old kexts around. Once I checked my /Library/Extensions/ folder and zapped the ones no longer needed, my issues went away.

If a clean Monterey install does not have the audio glitches, you'd have most of the answer. Comparing the Extensions folder to your regular install would probably solve the rest.