Are your 805s positioned too close to the front wall because you need to fill in the bottom octave and tame their too-hot tweeters? Sorry if I'm being presumptuous, but I tried the Nautilus (803/4s) series and found the tweeter way too hot (especially off- and above-axis), and had to sit very far away from them, which flattened the stage. I have a 24x14 room and sit in a 7.5' triangle, my monitors about 8' from the front wall. The stage is spectacularly layered, even with a 7' Steinway slightly behind the speaker plane. I found, however, that this setup works only with speakers that are utterly resolved and smooth in the upper octaves. The tizziness of the Nautilus tweeter (and the lower mid "honk" of the 805) did NOT work in my nearfield setup, although, interestingly the sound was satisfactory from an adjacent room! So: are your speakers pulled out from the walls enough to develop a 3D stage, and are they timbrally acceptable that way? If "yes" to both then I'm puzzled, too. I've no experience with the Planet or your pre, but I'd look at the preamp/amp stages next. Good luck!
3-D Imaging: How??
I'm finally satisfied with my current system, except for one thing: it is absolutely 2 dimensional except with a few discs in which you get a little depth. I have: Rega Planet, CJ PV11L, McCormack DNA.5, B&W Nautilus 805s. Interconnects are TARA Labs Master Gen 2, speaker cable is Audioquest SA-40 (hyper pure silver) on top, CV-4 on bottom(the CV-4 actually compares well to other cables I have tried) All equipment sits on marble slabs that are "tip-toed" to the concrete below my carpet. I'm using an Isobar Surge protector on the CD and Preamp, with a Sonic Horizons Daybreak power cord directly into the wall on the amp. The room is about 12" by 13", but I have a totally dedicated room with a good nearfield setup. Why is my sound 2-D?? Thanks guys!!