Might have cured my MacOS Aggregate devices problems at last!

Purusha · 2024-04-12T18:42:01.586Z

When using aggregate, to bring together various USB audio devices on my Mac, with Ableton and Cubase, I was seeing CPU spikes. those spikes were causing glitches / pops & crackles. This is an Intel MacBook, running Sonoma 14.4.1.

Accepted wisdom is that the non-master devices, should have drift correction ticked. I have that on my Kronos and Line 6 Helix. Cubase immediately had glitches and Ableton wasn’t too bad, but still saw the CPU spikes.

So I thought - wonder what happens if I untick the drift correction. Almost fell off my chair! Everything now seems to be OK!

If you’ve been having similar problems, could you try that and report back?

victorcampos · 2024-04-12T20:09:55.136Z

Careful because I think without drift correction the sample rates will get unmatched over time (no clock runs perfectly stable at 44.1/48/88.2/96 kHz, they all drift a little here and there).

Purusha · 2024-04-12T20:46:23.100Z

Hasn’t obviously failed yet in a fair bit of testing, but will continue to test. The CPU spikes are much more of a problem for me it seems

The drift correction is definitely causing glitches for me. Could be a buggy algorithm? …or maybe it’s just sporadically CPU intensive.

Only other solution would be to ditch the USB audio devices’ USB audio connection, which wouldn’t be ideal.

If a device is taking its clock triggers from the Mac’s USB and synching to that (which some do seem to do), then things should be OK unless those clock triggers get missed. Bearing in mind that many devices will synch to the host clock anyhow, if they’re providing analogue outputs.

Purusha · 2024-04-13T17:53:53.747Z

I’ll add that some devices need the drift correction, but others don’t seem to need it.

My A&H QU24, when running multiple tracks into the DAW, definitely seems to need it when it’s not clock master.

Korg Kronos, Line6 Helix and Roland TD50X don’t seem to need it.

With only QU24 having the drift correction enabled, things are (so far) looking good.