I don't run the sub hot at all (it is about 40% on the back) and was calibrated with an SPL meter originally. The rattle appears to be more related to a specific frequence (harmonic resonance?) than a particular level.

Looks like I'm calling Axiom Monday to see what they suggest as I'm not that keen to start dismatling it just yet!

Thanks
Nathan

HT:M80,VP150,QS8,EP500 Outside:4xM3 Office:AudioBytes, Rumpus: M60,VP150,M22 Portable:2 x Airs