I have a Peavey 215 cabinet loaded with relatively new Eminence Lengend speakers. The bottom speaker has a nasty rattling noise when I hit an Eb, E, or F on my B, E, and A string. The speaker is not damaged. When I took the grill off, I played these notes, got the rattle, and pushed on the surround of the speaker and the noise disappeared. I don't understand how that makes the noise cease. Please help me find a permanent solution to this annoying sound! Thanks!