[linux-audio-user] RE: Invert And Mix

[Jamie Lutch]

what works for me is to generate a sine wave (I used wavelab in windows),
then copy and paste it until it is several hours long, then insert 10
seconds of silence at the beginning. Start rolling your sine wav recording
from another machine with a known good soundcard, and start your test
machine recording in the silent period. Its super easy to sync up to your
original wav by deleting all the silence at the beginning.