I have tried REW using this mic, although REW is prone to operator error (when this operator is using it) so my measurements are not to be trusted 100%.
- I'm using a Mac, so I never know what input level to set the microphone at in Sound Preferences. I just pick halfway.
- I can hear the sub running even though I've set it to run only left or right speaker.
- I calibrated it to 75db using an analog SPL, but did I really?
- I smoothed the response to 1/6 which appears to match ARC results.
- Did I turn off the previous ARC calibration when I did this? I think so
1, 3 and 4 are fine and you can ignore.
5 should be ok.
2 is the way your AVR is setup. Quite a nice dip at the crossover frequency around 85Hz.
I would ignore everything above 5kHz as likely to be a signature of the mic and question some of what's happening in the bass as part of that. I assume it did not come with a calibration file so that it could be used with third party software.
Can you post the ETC graph?
Bottom line: are you happy with your sound? If not, time to invest in an UMIK-1 and new AVR, and possibly new speakers.
If you are unsure, try to borrow the best speakers you can and try them in your room. They are the main determining factor, not the room.