Yep, I found the same with M2s.

If you place a normal speaker on its side the apparent location of the sound changes depending on the frequency, which really blurs imaging. If you have a symmetrical driver arrangement (either a purpose-built center channel or two regular speakers with mirror-image placement) that problem goes away because all the sound seems to emanate from the center no matter what the frequency.


M60ti, VP180, QS8, M2ti, EP500, PC-Plus 20-39
M5HP, M40ti, Sierra-1
LFR1100 active, ADA1500-4 and -8