So, what is the difference between buying a pair of M5HP and putting them on a tall stand to get them higher up. or Buying an M60, and putting them on a smaller stand to raise them up a bit?
I asked about this a while ago... the answer (from Andrew IIRC) was basically that floorstanding speakers are designed around a certain degree of "ground bounce" (I think that was the term) and that raising them would affect the mid-bass response a bit, in addition to the loss of bass reinforcement. The recommendation was to tilt them backwards a bit rather than lifting them.
When I tried lifting my M40s about 8" I found the change in sound was noticeable and not as good, although it must be noted that the track I was using for evaluation was the start of "Echoes" where the bass line begins to play under/against the piano, so the focus was on depth and linearity of LF response. Lifting about 4" was an OK compromise - got the drivers closer to ear level but without hurting the LF response too badly.
I don't remember if I tried raising the M60v4's - I should have though, since one of the things I didn't like about them was boomy bass in my living room, although I think some of that was a function of the setup rather than the speakers. I only had enough space to pull them ~3 feet away from the wall and that never seemed to be enough in that room (although it is enough in a different room)... I did try port plugs and that didn't seem to help much.
I don't think there is anything in the manuals about not lifting floorstanding speakers, at least I don't remember seeing anything about it. When I did some simple calculations (figuring out the first cancellation & reinforcement frequencies from raising the woofers a foot) I think the numbers were something like:
on floor - cancel 137 hz reinforce 275 hz
up a foot - cancel 90 hz reinforce 180 hz
I never had enough free time & motivation together to haul the M60ti's and M60v4's to the same floor so I could A/B them properly... all I remember is that the M60ti's sounded great in the living room once I fed them enough power and got the position right... but the M60v4's never sounded right.
M3's, M5HP's, Sierra-1's and M40's also all sounded good in the same position so it might have been something off with the speakers, but they sounded pretty much the same when I fed them a mono signal and switched from left to right so wasn't something obvious like a dead midrange.
Putting the Sierra-1's against the M5HP's was interesting - it was the first time that the speaker pairs I was A/B'ing didn't sound like chalk & cheese... they still sound different in tonal balance / frequency response but without a switch box and more free time it's hard to describe the difference properly or even say which one is closer to "right".
