I’m running Audacity 3.1.3 on a brand new Mac Pro with M1 chip, Monterey OS. Recording with a professional large-diaphragm mic interfaced through a PreSonus Audiobox USB 96.
When I try to record, Audacity defaults to mono in the left channel only, and I have tried everything I can find in both Audacity and Apple help channels to get both left and right channels running. No luck.
If it matters, Audacity will play back stereo that was created elsewhere and the VU meters read both channels, but when I try to record, left-channel only.
Anybody know what’s up with this?
Windows guy here: No.
So in the Audacity Device Toobar see Device Toolbar - Audacity Manual, you can choose to record from 1 or 2 channels.
If this doesn’t help, post the contents of Help > Diagnostics > Audio Device Info. Perhaps there will be some clues hiding in the details.
Sorry Jademan I’m new here and don’t know how to highlight part of your reply, but here it is:
So in the Audacity Device Toobar see Device Toolbar - Audacity Manual, you can choose to record from 1 or 2 channels.
I have attached a screen capture showing that the Device Toolbar reflects two-channel stereo recording, and the correct input/output devices, yet the ambient sound showing in the VU meters is only on the left channel, the waveform of a test recording also shows only in the left channel, and playback is heard only on the left channel.
I do believe this is an Apple problem, not Audacity, because it never happened until I switched to Mac a few weeks ago and only just now started using Audacity there. Never had this problem in Windows.
Once again, the machine is a brand-new Mac Pro 13, M1Chip, Monterey OS. I’ve already learned that my Logitech C390e will stream but not record pictures or video on the Monterey OS, so I’m wondering if there isn’t a similar incompatibility here.
Recording with a professional large-diaphragm mic interfaced through a PreSonus Audiobox USB 96.
A single microphone (or a single voice) is mono. Stereo requires a left microphone AND a right microphone. 
A true-mono file will play through both speakers.
To make a mono file click the little drop-down arrow to the left of the waveform and select [u]Split Stereo to Mono[/u]. Then (also to the left of the waveforms) click the little “X” to delete the silent track.
You can record in mono, but when you record in mono from a stereo interface the signal(s) are cut in half (-6dB) to prevent clipping (distortion) when left & right combined. If you’re only using one input you’ll end-up with lowered levels, so either way you’ll have to make an “adjustment” after recording.
