I hooked up the new Crown XLS-1500s today and also played around with audyssey and REW to analyze audyssey / S2 level issues.
I originally reported that Audyssey was setting my S2 6-10 db lower than the mains and Jedirun suggested manually setting the level to 75 db before running audyssey. I tried that today but Audyssey pushed the sub level even lower (to -7.5 instead of -2.5) and ended up at the same absolute level.
Ufokillerz pointed me to RS SPL meter correction files. I used them with REW today and measured the frequency response. The test confirmed that Audyssey is indeed having problems with properly level matching between my mains (Quintuples) and the S2.
See the blue line in the attached FR graph. Note that this measurement represents the sub level after I bumped it up by 2.5 db (-5 db instead of the original -7.5). I also learned that I have a null which is causing a dip close to 110 Hz.
I played around with audyssey settings, sub levels, and many crossover settings. Finally, I managed to achieve a pretty decent FR by switching to audyssey flat, setting the sub level to -2.5 (5 db higher than the Audyssey-selected setting) and raising the crossover setting for mains to 120 Hz. The purple line represents my final configuration.
Impressions on the crowns to come later. They are light weight with a solid-build feeling and very quiet!