Hi guys. I was playing through my Mesa PH412 the other day. The cab didn't sound punchy as it usually does. I EQed the amp(M9 Carbine) and got a decent sound out of it. Then it started to make a this horrible noise and I could see sparks from the top right driver. I've never had a speaker blown on me so I don't know. I'm sure that the driver is dead but what could have been the cause? I was playing at low volume and I've never pushed it. Was it a faulty driver or did something else cause that to happen? Thanks for your help.