Today I started recording a screencast in ScreenFlow for a demo on how a software product works. I went back to edit and heard static all throughout the mic track. I started doing tests in Wiretap Studio, changing headsets and iMics and all kinds of things trying to get a handle on what the issue was.
Finally, I started poking around in the Audio/Midi setup utility (found at /Applications/Utilities/Audio MIDI Setup.app) and noticed something. The Audio input settings for the iMic USB audio system were set to 48kHz 1 channel 8-bit. I changed them to 44.1kHz 1 channel 16-bit, and the recordings were crystal clear again.
The settings causing the problems:
The settings that fixed the static issue:
I’m not sure what changed them, but some app that uses audio did something and it resulted in static-filled recordings. There was a constant background noise regardless of whether I was speaking or not. If you find your recordings suddenly sounding really bad and you’re sure you haven’t done anything obvious, check the Audio Midi Setup utility and make sure things look right. Make sure in the “Properties For:” dropdown you select the input device you’re using.
Update: In retrospect, I guess I should have set it for 2 channel 16-bit.
