Monitor Audio GR 10 Speaker Trouble

Hi Tech Folk,
The other day I forgot to shut off my ASR Emitter II amp before connecting the spades to my Monitor Audio GR 10 book shelf speakers (I did reduce the volume to low power). I was using my Quad 2905 ESL's as my primary speakers which require a great deal more power than the GR 10's. My initial plan was to watch a movie with the two pair of speakers connected but diverted into CD listening territory. Shortly thereafter I began to hear a buzzing noise from one of my GR 10's.
I was running standard copper Transparent 10 gauge wire to the box speakers and they were connected to the treble posts at the time. I've switched out the speakers to see if it was in the cable, etc... but nothing. It's definitely in the speaker however it's undetectable by looking at the surface. Admittedly they were being pushed pretty hard but my ears weren't bleeding. I'm wondering what I could have done and what it might take to fix it.