Thanks for the replies. I've done some more tinkering, and it's pretty clear now that the main problem is speaker placement. I hooked moved the speakers to my main system (Marantz 2 monoblocks, Marantz 7 preamp, Music Hall CD 25) and two things happened: The midrange was far more integrated with the treble and the boominess of the bass disappeared. The soundstaging was even more dramatic and impressive. I DID notice some shortcomings I had not before, in comparison to my main speakers (Tangent RS4). More on that in a moment, just FYI.
That experiment leads me to believe that the bass problem comes from the placement -- the little echo chambers behind created by the lowest shelf. And I supsect that the slightly recessed midrange comes from the Cambridge Audio amp's relation to the M3s.
Okay -- so that still leaves me the question of what to do. I'm inclined to order the M2s and just see how they compare, and return the loser in the head to head. If reports are to be believed, I'll be happier with the mids in the M2s. My concern is that the bass boominess will be solved simply by reducing bass output, whereas the better solution would be to somehohw tighten up the bass. But I don't know how to do that without moving the speakers, which won't happen.
Maybe some sort of sound baffling behind the speakers? To soak up some of that bass reverb? Anyone have experience with that sort of thing.
Now, if you're interested the M3s vs the Tangents. Tangents are rare. Sold in the US briefly in the 1980s. I believe I read somewhere that the Axiom is somehow a descendent of Tangent. The one clear advantage of the M3s is soundstaging. THe music was all over the room in a way the tangents couldn't match. The treble on the Tangents also at times had a slight harshness when turned up to a high volume (they're very insensitive speakers, rating 84 or 85, I think). But the Tangents had a much fuller sound, with the bass and especially the mid and treble more seemlessly integrated. But the main advantage of the Tangents was that everything sounded more natural, real. I noticed this first on drums. Drums sounded like they were in the room, whereas on the Axioms they seemed like a good reproduction. Probably another way of saying the same thing, the Axioms by comparison (note: I didn't notice this before a direct comparison) seemed to have a slightly grainly film. So with the soundstaging, it seemed that "particles" of music were all over the room. WIth the Tangents, less presence, but no "particles." Just clean sound. Now these speakers wouldn't be considered competitors in any real sense, so all this has to be taken with a big grain of salt, and overall the Axioms did great, esp considering the price. But I thought this comparison might be of interest.
