Easily strong enough. I used the full metal bracket with the QS8's for awhile, til I switched them to my bookshelf speakers that I use for 7.1, with no problems.

2xM80 VP180 2xQS8 2xM3 HSU STF3 LG 60PS11 Denon 3808 ATI 1506 LCR 2xATI 1502 Oppo BDP-83