nautilus 801 bass accuracy

calling on 801 owners and anyone with many hours with 801's.... I'm trying to figure out if the lack of definition and boom on bass guitar on some recordings is inherent in the speakers or something I can correct. this quality or, lack of, is enough to want to stop listening. I could be exciting a room mode but at this point I'm not sure. Actually on some recordigs I can identify it as standing waves. other times it appears to be muffled bass from some recordings and it stands out because the rest of the sound is so great? I've noticed some owners on audioreview say if the source equipment is low standard you will get this? I'm running a AI mod 3 through 2 bryston 4bsst bi amped but my cd player is rega planet 2000 and turntable is an old planer 3 with clearaudio cartridge.
Your help is needed. Thank's