Best answer by Airgetlam
On the other hand, I've got a Sonos One sitting on a shelf in my bathroom, and noticed today that with some low bass (Tangerine Dream's Zeit), it was rattling a bit. So I'm going to get a rubber mousepad for it to sit on. If you're having issues with your wall mounts rattling against the wall, you may want to put a rubber isolation layer between the mount and the wall. Or just torque the screws down a bit more. You certainly shouldn't have the mounts rattling/vibrating at all.
Not sure if I've been helpful, since I don't own any of the Sanus mounts.