Noise floor level changes depending on which app is in foreground

[Tony359]

I have two identical 42TB NAS with zfs, one mirror of the other + online backup for the most critical stuff. I know what you're talking about

 

[Redacted]

Hah! Plenty of space for regular drive imaging then!
And a few CD rips.

 

[DavidR]

I read through the thread due to the interesting nature of it. You never know when that knowledge will help later. When I saw that Audition is Adobe software I wondered if it has to do with Adobe doing updates or installing a task in background. I've had two instances of Adobe running a background process, I think it was CoreSync, that was using a lot CPU suddenly. In my old Win10 desktop and Win11 laptop. I use Adobe Acrobat that I believe installed the background task. I stopped and disabled it. The excess CPU time ended with it. I wonder if an Adobe background update introduced something into your system that is a background task causing your problem. The background task I found was new to me. It doesn't run all the time, of course, but I found it when my older, slower system became less responsive. I found the source, Adobe, when I ran Task Manager at the time. I have also disabled it in my relatively new Win11 laptop, although it never had a very slowed response. I've also disabled Adobe automatic updates.

This may have nothing to do with your problem, but Adobe seems to do things behind the scenes without user interaction or knowledge. I've had issues with Adobe in the past using a lot of CPU time.

 

[Tony359]

Thanks for reading through this weird subject! CPU usage has been mentioning many times but there is a "but".

I can trigger the "bump" on and off with Ardour.

Ardour open: no bump
Ardour closed: bump

I kept an eye on task manager, there is really nothing happening in the background. Even if it was an update or anything, it wouldn't happen all the time.

I've switched to macOS now and the issue just doesn't exist - for now.

 

[DavidR]

Just a thought. Does Ardour take exclusive use of ASIO when running, then release it when you close that then triggers some other process to take shared use in some way? I had to learn the issues with ASIO in REW solved via FlexASIO.

 

[Tony359]

The RTA software does work when Ardour is active - even when playing. I thought about some ASIO issue but I don't have an issue, just that weird bump at -120dB which is, obviously, not an issue for everybody but me

Is there a way to use different ASIO drivers with the 18i20?

 

[DavidR]

I don't know, I doubt it. I believe that FlexASIO is presented to the using software as a single ASIO instance. FlexASIO then accesses the specific ASIO drivers for whatever choices are available for the I/O points selected. It provides options for exclusive access or not for input and output independently. FlexASIO identifies all ASIO drivers accessible for each I/O shown.