Help! Screeching in my speakers...

[Visionist]

So when films get loud, either music or effects, one of my surround speakers will randomly start screeching at a high pitch, very unpleasant. For 5.1 films I've had to disable the rear surrounds as the left was always screeching, and now the right forward surround screeches as well. Connections are all solid.

Am I simply playing them too loud for the power my little Onkyo puts out? I don't know if they're damaged, I sure hope not. I'm coming to dread watching anything new as modern action films and the like are very loud at the volumes I play them at.

My Jamos were purchased pre-loved over three years ago, they've been fine till now...