[brucek]

When you use the loopback cable to check the results and effectiveness of your soundcard calibration file, you must (for this test only) clear the microphone/meter file, since the loopback cable obviously requires no calibration to be perfect.

So, if you have a proper soundcard cal file in place and forget to clear the microphone/meter calibration file and then perform the cable loopback test, you will get a graph that looks exactly like the inverse of the microphone/meter file. This is what I see in your graph (except you have substituted the C-Weight file instead - unclick it for this test). So, I would say you're good to go. To verify, do the loopback test with the mic/meter file cleared and the soundcard file in place.

Then you're ready to do measurements. Be sure to make your measurements with the mic/meter file loaded (and check the C-Weight box) so as to compensate for the meter.

When you post your graphs, the standard we use here is a 75dB target, with a horizontal scale of 15Hz to 200Hz and a vertical scale of 45dB to 105dB....

brucek

Note: The C-weight check box adds a C-Weight to the microphone readings outside the limits of the mic/meter file. So if the mic/meter file goes from 10Hz to 100Hz, then C-Weighting takes over (after that and before that) if the C-Weight box is checked. With no mic/meter file, then C-Weight takes over the entire range.