Got crackling audio in MainStage 2.2.2? I did, and here's how I fixed it...

A lot of people are talking about an issue in MainStage 2.2.2. where crackling audio gradually builds in the signal and eventually becomes unbearable. I had this issue but none of the solutions I found in the support community worked for me.

The obvious fix is the increase the sample buffer size until the issue goes away (as it's often a matter of the CPU not being able to handle the load, especially on older machines). You can also turn on the Safety Buffer checkbox, which can further reduce the problem. My issue wasn't solved this way, unfortunately; no matter how high I increased the sample buffer, the problem persisted.

It seems the problem was being caused by my USB interface, which is a very good unit (the Focusrite Scarlett 18i6). My first mistake was that I used the Scarlett for input, but used built-in output. I suspect the Mac (2012 non-Retina MPB, 2.3GHz i7, 16 GB RAM, SSD) had trouble synchronizing with the device. I routed the output to the Scarlett as well and that seemed to fix the crackling. I had a problem with the device putting the dry signal Mainstage, which wasn't good. I then downloaded the software mixer (found on the Focusrite site) and, when I tried to run it, it told me the Scarlett needed a firmware update. So that was applied. I then ran the mixer and chose "DAW1" routing preset. After that... no more problems at all.

If you're having this exasperating experience with crackling and the buffer size doesn't fix it, perhaps the steps I took could help you find a solution as well.

Good luck!