[felubo]

JohnM, I am using a ECM8000 mic to record the response but even if I were to use the SPL meter, it has no "record" button on it. It appears that the output of the REW signal generator is getting to the sound card through the PCI buss because I can see it displayed on the M-Audio Mixer panel. It just is not being outputted through the sound card to the audio receiver. Whats strange is it works if I press the "automatic measurement" button or the "calibrate" button of the REW program but nothing if I utilize the "Set Measurement Level" or Set Input Volume" buttons. In order to get around this problem I have been utilizing the "calibrate" function to get an output from the sound card and adjusting the volume control on my receiver until I get a output of 80db as read on the Radio Shack SPL meter and then inputting 80db back into the REW program. I'm not sure if this is correct but it seem to allow me to get the correct frequency response when I then press the "automatic measurement" button.