It's a midrange/woofer on top, not a tweeter, so it should be OK I think. I ran one of my QS8s with the bottom a few inches off a table (back in the soup can days) and didn't really notice a difference compared to the other QS8 which was mounted on the wall with the T-bracket.

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