Luxman M900u stereo vs Mono setup

I'd be interested to hear someone's comparison, too.  I run TAD CR-1's, and recently acquired an M900u to try with them in place of the PS Audio BHK 300 mono's that I have been using.  The stereo Luxman amp is bringing some clear virtues in the mids and highs in terms of revealing musical and harmonic information, and that is appealing; but I find that I am not as happy with its low-mid bass, where it seems less distinct, almost feeling a bit vague.  This surprises me, given the 700+ damping factor that the Luxman boasts - - I would have expected greater control and definition, and I am hearing the opposite.
Yes, the stereo Luxman seem able to play loud enough in my 22.5' x 15' x 8' room.  But the bass quality in the match to my speakers could be better, I'm feeling.

So, if going to mono blocks would improve this bass issue, then I would have to consider if I can go that far in budget!  I hope someone has direct experience that can speak to this aspect.

You can ask the OP (as noted by spinaker above) of the MY LONG LIST OF AMPLIFIERS thread. Im sure he will be happy to provide you a detailed account of his Luxman m900 Monoblocks.  They are his favorite "affordable" amp to date...and that's saying something

Hello, I own a Luxman M900u as well. I would not go running off and buying another 900u. I would consider the other gear you have connected to the amp. When inserted my 990u the mid bass and bass got better. The speed and leading edges were nicer. More real. There are so many other things that affect your mid bass and bass that my have nothing to to with the amp. I feel that the source is the most important and the amp will more than likely show the good or the bad of that signal. Given a great signal, the Luxman M900u should give you what you are looking for. But for the great signal to get to the final destination, the amp... the signal goes through a lot of other gear and cables...... so..????But if you are still wanting another Luxman M900u ? I'm considering selling mine....as I have much more gear to play with....

Room treatment, especially bass traps can make compact monitors sound a lot bigger and tighter.

I'm a big Luxman fan by the way, for much of the reasons described above, but if you haven't looked into the room, or if you inadvertently moved your speakers between amps, that may be the cause.  According to the Stereophile measurements, those speakers are 4 Ohm minimum through the mid-bass, shouldn't be any problem at all.

I certainly agree that a 4 ohm load shouldn't cause a difficulty for the Luxman amp, in theory, and that is part of the puzzle.  I have not moved speakers even a mm, just subbed in the Luxman for the BHK mono amps and I hear this difference in bass.  My room is extensively treated, including bass traps.  I use high quality cabling throughout, cables that have made every other component they've been hooked up to sound excellent.  But it just might be that this needs some sorting to get the best of the Luxman. 

I will try some speaker placement work to see if there is a new "best spot" given the change.  It would be delightful if that ameliorated the issue, because the rest of the spectrum has a lot of plusses.  I sure wasn't expecting a bass quality issue....