@woody - have you read and followed the Audyssey 101, in detail? It is linked in my sig. Setup procedure is very important for Audyssey if you want to get good results.
One thing is certain, you will not get the same low end with XT as you used to get with the lesser versions of Audyssey.
Please confirm you have followed the Audyssey 101 to the letter and we can continue to troubleshoot if you have. Pay special attention to mic orientation (point it to the ceiling), mic positions (use all of them, spaced as recommended in the 101). Also, please confirm how you are holding the mic - a boom stand, tripod or what? This is especially important. Also, do you have wooden (suspended) or concrete floors in your listening room?
If you only had 2EQ or MultEQ on your last unit, XT will sound very different because of the extra work it does to the bottom end. There is every chance that you had peaky bass before and you have simple become used to it. Remove the peaks and it can sound as if something is missing. It is - the lumpy bass! I generally suggest listening for a week or so to evaluate the bass before taking any further action. If you are not used to flat bass, it will sound lacking at first - but once you get used to hearing all the bass as it is meant to be heard, most people prefer it that way. A good test is to play a CD or DVD of some bass-heavy music (I use Stanley Clarke or Jaco Pastorius or someone like that) and listen carefully to the bass notes. Do they all sound the correct loudness, without some notes being emphasised and others diminished? If so, chances are you are listening to much flatter bass than you are used to. Turn Audyssey off and listen again - does the music now sound 'lumpy' in the bass region?
It's after 12.30 am here now and I am about to go to bed - I'll pick it up again with you in the morning.
Thanks so much for the help everybody!
I went through the Audyssey 101 pretty thoroughly with my Onkyo 706. I think I'm doing everything correctly. Mic is pointing toward the ceiling. I'm clustering all of my mic positions around the main listening position (the other listening positions are on a couch too close to a side wall). The mic is attached to a tripod. I have wooden floors.
I went from MultEQ on my Onkyo to XT on my Denon. I was under the impression that subwoofers were handled the same way on both. I just think it's really strange that I set my sub at 50% volume and Audyssey set the trim to -5 with my Onkyo. And with the Denon, 50% was way too loud and I couldn't get a reasonable trim until I set my sub to 25%. Overall, things just sound weak in the lows and even a bit muddy in the highs compared to my Onkyo.
You guys could definitely be right -- that I just need to let the new settings settle in, but at least to my ears, it sounds pretty awful at the moment.