From the installation manual it shows there to be a slotted "L" adapter that looks to be tall enough to be able to use the single bolt already on the back of the QS4, if the "L" bracket is not tall enough you could proabably find some flat metal/aluminum and drill a hole at either end to extend the length of the vertical section high enough to be able to mount the QS4, no extra holes required in the speaker.


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