Okay, as promised I got up early this morning to do some more intensive measurements than I have before, now that I'm armed with a little more knowledge using REW. Early because I didn't want to have to have to fight the heat again with me with turning my HVAC off and on for measurements. I unplugged my fridge too and got the noise floor down to ~ -70.
I started off by taking 8 new Audyssey measurements (at six in the morning) using first the app and saving the calibration file on my tablet. Then I took 8 new Audyssey measurements using the receiver by itself.
REW:
I used the Audyssey calibration file I took last, using the receiver by itself for measurements (since it was already in there) and took 2 sets of REW sweeps. 6 for my main speakers (both at the same time) and 6 for my subwoofers, placing the mic in the same pattern and height (about 1" over the back of the chair) that I took my Audyssey measurements from.
I could only get 6 REW measurements because the cables I have aren't long enough to get 7 and 8 behind the chair. I think 6 is pretty good though.
I then uploaded the calibration file from my tablet, wash, rinse and repeat with REW measurements. I averaged the 2 sets of 6 for my mains, did the same for the subs measurements and made a couple of overlays. Between REW and Audyssey I think I took 28 measurements altogether this morning. These are my results.
These are the sweeps I took for my main speakers. The red line is the receiver by itself. Purple is the calibration file I uploaded from my app. They're really pretty close. I can see what I'm hearing that's different though. They're not night and day, but the difference is audible to me. This is very consistent with what I've been getting over the last few days. I kind of prefer the receiver's curve here. Happy with both, really though. I acknowledge the differences are pretty small.
Subwoofers! Here, imo, is a fairly significant difference. The purple line is the receiver by itself and the green is the file I uploaded from my tablet. This is very consistent also, and believe me, I've taken many, many measurements over the last few days. I have a reasonable sample size to pull from. I'd say my favored curve should be pretty obvious here...
It looks like the averaged measurements are a little kinder with that 34hz peak and 42hz dip. It's really very good right now. I'm just spinning around in this rabbit hole... Still waiting to hear back from Chris on it.
*Edit: I just bumped the thread on facebook I have with Chris. I only uploaded the overlay of the subs. He asked for averaged measurements yesterday. I was kinda done with measuring by that time, lol.