So I just got a used GK SBX 410+ from guitar center. I've had it for less than a month. About two weeks ago I noticed that the sound was a bit harsh on the high end, but I figured that maybe I was just used to a 15" speaker. Today I ran the speaker along with a GK GLX 410 using 1/4" speaker connections from my 700rb. Everything went rather well, I was running my woofer and volume at about 10:00 - 1:00, depending on the song, and during one song I used an ODB-3 in a song that's in low C#. I was playing my Stingray. We take a break from practice and I come back to hear a rattling and crackling from the upper right speaker and it looked like it was moving more and faster than the other speakers, but sound was still coming out of it. I tried switching cables, amps, everything, nothing fixed it. Is my speaker blown? If so, how should I go about fixing it?