In article ,
Mark D. Zacharias wrote:
Don't remember what web site but I was able to download a couple drum
samples which greatly aided my troubleshooting once. The piece I was
working on didn't even act up using sine waves, only when lower
frequency music was being played.

The best check is a warbling sweep. Check out the one I suggested earlier.
That's what speaker makers use.

--
*"I am " is reportedly the shortest sentence in the English language. *

Dave Plowman London SW
To e-mail, change noise into sound.