Mine are below my Sammy DLP. And it also does make a difference weather ur speaker is above or below ur TV. Make sure u angle ur speaker towards the listener.
BTW how in the world did you manage to put the 150 on top of the Sammy. Isnt the top a little too narrow? Do you have it like on the TV itself?

Axiom M60ti, QS8, VP150
SVS PCi25-31
Yamaha RX-V571
LG Plasma 60PB6900
Sony PS4 BD