The Sony should be ok, check to make sure the 2 straps under the speaker terminals on the M60s are flat against the post, if one is off you could be losing some sound.

You could also just be used to the boomy sound older/cheaper floorstanders have compared to the Axioms.

Jason
M80 v2
VP160 v3
QS8 v2
PB13 Ultra
Denon 3808
Samsung 85" Q70