First, my setup:
I'm using an M-Audio MobilePre external soundcard running on Windows XP laptop.
(see below for pic of front and back of soundcard)
Next, my problem:
I've been trying to get REW working so I can take some full frequency sweeps of my speaker system. I've been having issues. The first issue is just calibrating the sound card. I'd expect my soundcard to be pretty flat across the entire spectrum.. but I'm getting the following soundcard calibration file for it:
Finally, my question:
What the heck is happening in that 100-600hz range? Is my sound card damaged somehow?
BTW, the issue is repeatable. Everytime I try getting a new calibration file, I have the same graph.
Oh, the loop I'm using for the calibration is a connection from the
1/8 stereo line out to
1/8 stereo mic input connection with a 1/8 to 1/8 stereo patch cord.
JCD
