I know you do not have an SPL meter (measures dB basically) but those speakers at + anything must be ridiculously loud. I have the same receiver (2310) and only little W22's and the loudest I have ever had it for about 30 seconds was +3. Normal loud listening is around -5 to 0, and even that is somewhat rare.
I do have to agree you are probably limited by the amp in the 890, as opposed to the speakers. Really though, listening that loud over time won't be good.
EDIT: I just saw Alan's point about rock concerts... I've been to more than a few, and they are freakishly loud, but I must admit they don't seem as loud as about ten years ago. One show, I was at a small venue and I was standing beside (two feet away or so) one of the floor speakers beside the stage for a good hour. Being so close and not wearing earplugs was stupid, my right ear was ringing for four days, no joke. Don't want to go through that again
