Sorry to resurrect a year old thread, but I didn't want to start a new one when this thread is already here...
I've done some comparisons of ARC (on an Anthem MRX310) and Audyssey XT32 (on a Denon X4000), and I'm a bit confused about the results. Neither room correction system seems to be doing much. Both were ran according to the recommendations of their respective manufacturers. I've experimented with speaker placement on both systems with three different sets of speakers (KEF R700, JBL Studio 580, and Zaph L18 DIY build). Below are a couple of examples (the only screenshots I have handy, the REW was run on a different PC than I'm using to post this). Even though these show only Audyssey on the Zaph's and ARC on the KEF's, I've run both systems on both sets of speakers and the results are similar.
Zaph L18 Audyssey off (green) vs Audyssey curve (blue)
Zaph L18 Audyssey off (green) vs Audyssey Flat (red)
R700 ARC on (blue) vs off (light purple)
The above are all done from the main listening position; 1/12 octave smoothing. It looks to me like not much is happening, and in most cases the uncorrected response looks maybe a bit better to my eyes.
The room is L-shaped and the speakers are on the short wall at one end. The room opens to a hallway in the inside angle of the L and a stairway near the other end. The outside walls of the L are about 30, both ends are about 14 feet, and the ceiling is 8'. The end with the speakers is treated with GIK acoustics soffit bass traps (one in each corner), 242 panels on first reflection points on side walls, and for these measurements there was a 242 panel behind each speaker (I found this in earlier REW sweeps to best smooth out the peak/dip combo from the front wall reflection. Also, in the above measurements speakers were located about 1m from sidewalls, and 1.3m from front wall. LP is about 13 feet from the front wall, equidistant from the speakers. There are GIK 242 panels with diffusor plates along the rear wall facing each speaker.
Am I expecting too much from these room correction systems? Maybe my room issues are way too bad for them to even begin to help, or maybe the room isn't that bad and the easy to correct stuff has already been taken care of by the limited amount of treatments?