help with recessed lighting fixture vibration

I like to listen to music and movies very loud. I have Axiom speakers and an Outlaw LFM 1EX sub, run with a 990/7500. It does play loud, which I like, but I have a few recessed lighting fixtures in my HT that have a "wall washer" insert in them (to direct the light onto the wall, not straight down). Anyway, they are essentially just half-moon shaped metal plates that cover the light opening. They free float in the light opening so they can be turned to adjust the path of the light. When I really crank thinks up, the metal cover vibrates and starts to spin around. The result is a buzzing sound that is quite annoying. I would try jamming some foam up there or something to dampen the vibration, but the light gets pretty hot and I wouldn't want to create a fire hazzard. Of course, one solution would be to turn down the sound, but I don't want to do that

Any suggestions?

I've got a couple possibly crazy thoughts...

I might try getting some thin armaflex or other insulation material from the hardware store and cutting it up a bit into pieces that could be good wedges. We put armaflex on pipes carrying 200 degree water, so I'd think it would be comfortable a couple inches from an incandescent bulb. Another thought (not having taken apart a wall-washer recently) would be to pull the trim off the can light and use a few sheet metal screws or something to affix the aperture to the frame so it can wander and vibrate, but I don't know if that'll work structurally and it will make it effectively impossible to adjust your aiming later.

Both excellent suggestions. Thanks gonk!

Glad to help. Hope you get the lights under control soon.