Audio Interface gets VERY distorted while using DP.

[happymoogman]

This has been driving me crazy. For years I had a Presonus Saffire audio interface for my Mac and DP. It worked like a charm, and was trouble free for about 10 years. Then, one day it died. I recently replaced it with another Presonus product, the Studio 24c.
After a couple of hours, the sound going through THAT started getting VERY distorted. If I unplugged its power source and then replugged it back in, it would work well for a couple more hours, then get horribly distorted again. I tried plugging its USB connector directly into the back of my Mac, to avoid any USB hub issues. Same problem. Sp, I assumed the Studio 24c was defective, and I returned it for another 24c. Same problem. Frustrated, I returned that one as well, and this time got my money back.

I already had another audio interface on my other computer, an SSL 2+. So, I moved that interface over to the my main recording computer, assuming that all would be good. Same problem happened. It seems to only happen when DP is running.
If I play DP's audio through the computer's built-in speakers or headphone port, everything plays fine. I checked my monitors, and they are fine, too. No, the output levels are not overdriving the audio interface.

Any ideas??? Help.

[apanacci]

Hey Happy that happens to me occasionally and I shut down DP and trash or replace the MAS audio preference then restart the computer. Try that see if it works. I make copies of my MOTU preferences when all is well and use those to replace when the audio gets distorted. Hopefully that works for you.

[mikehalloran]

A reboot does not take care of this?

[happymoogman]

Hey Happy that happens to me occasionally and I shut down DP and trash or replace the MAS audio preference then restart the computer. Try that see if it works. I make copies of my MOTU preferences when all is well and use those to replace when the audio gets distorted. Hopefully that works for you.

Thanks for that. As I mentioned, if I simply reboot the audio interface, the audio goes back to normal. No need to reboot DP or the computer, itself. if I play the audio through my mac's internal speakers, there's no distortion at all. After buying THREE new interfaces, it's hard to believe that each one of them is defective.... I'm really puzzled.

dc

[cuttime]

This sounds like a heat issue. Is the unit in a ventilated rack?

[mikehalloran]

I don't think it's your interface.

Another user contacted me about this and I was able to duplicate it. No interface was on at the time.

When it happens to me, the Real Time bar in the Audio Performance window lights up full red. Quitting and re-opening DP made it behave but there are a couple of projects where this is a problem.

I intend to call MOTU on Monday.

Real Time Audio Performance Meter.png (32.68 KiB) Viewed 9002 times

Here's how to set up DP to show that window.

Set Up Audio Performance window.png (258.37 KiB) Viewed 9002 times

[mikehalloran]

Long talk and screen sharing session with MOTU Support today. Again, I'm getting this without any interface connected. One of my projects is particularly prone to this.

We started DP in Safe mode by hitting the Option key, them selecting Safe from the drop-down (see below). This disables all plug-ins. In Safe mode, we could not get my system to act up again.

I have a lot more testing to do and it's possible that one of my bread & butter plugs is the troublemaker and not completely Sonoma or DP 11 compatible. My only other on the problem project is Melodyne 5 Studio.

I am not completely convinced that we found it. Starting DP in Safe mode is something that everyone can try. Please post your results to this thread and I will include them in my open Tech link. MOTU is very interested in this issue.

Screenshot 2024-01-09 at 1.10.56 PM.png (1.72 MiB) Viewed 8808 times

[mikehalloran]

This has been driving me crazy. ...

Hey Happy that happens to me occasionally and I shut down DP and trash or replace the MAS audio preference then restart the computer.…

Just quitting and restarting DP worked for me — till it came back again.

Update:

Working with Caleb at MOTU support and talking to other users, we are convinced it has nothing to do with interfaces, The Real Time bar is showing background processing, not interference from the interface. I was able to make this happen with no interface connected.

If you do not have the Real Time meter showing, see my earlier post on one of the ways to display it in Settings/Preferences (there are other ways). This lets you see the problem in real time.

Follow my instructions for starting DP in Safe mode and click OK when you see the missing plugs list. The RT Window should now look like this:

Screenshot 2024-01-14 at 11.59.54 AM.png (17.87 KiB) Viewed 8601 times

Now Quit (do not Save) and restart. As the window bounces, disable your plug-ins one at a time. Go to the mixer and Right-click on the plug selecting None from the drop-down menu till you find the troublemaker(s). The RT window will idle or barely move once you've found it/them (this is so much faster than disabling 50% of your plugs in Settings and going from there). Quitting without Save will reenable those plugins. You can also use that same dropdown to reenable or find alternate plug-ins.

Screenshot 2024-01-14 at 12.07.04 PM.png (270.08 KiB) Viewed 8601 times

[mikehalloran]

Some plug-ins cause distortion without the RT Window going to the red but they should make that green bar dance.

MOTU's MW Limiter does this. I and others have known for years that too many instances caused my tracks to distort but now I could actually see and demonstrate it to MOTU—the RT Meter bounces a lot but never goes to red. Caleb says that he'll refer it to Engineering but can't promise anything will be done, of course.

In my case, the problem child turned out to be bx_limiter True Peak, the very plug that solved my problems with MW Limiter three years ago. Turns out that I was on version 1.80 and had missed the 1.81 update last November that addressed this very issue (and James had posted that notice in Plug-in Updates at the time — oops!).

Had I not been running that older version, I never would have seen this and escalated it. So case closed.

If anyone is still having this problem in Safe Mode, then it's something else and MOTU does want to know about it. Caleb is the tech most familiar with the issue.

[HCMarkus]

Great work Mike and Caleb!

[happymoogman]

Thanks, Mike and Caleb for your attention to this issue. I hadn't checked Motunation for a while, because the problem seems to have gone away....for now. I'll keep your notes handy, if it ever acts up again. (I'm not doing much recording lately.)
dc