i have an 800 watt rms 410 speaker cab. i havn't had it very long, i was playing a small gig and my amp started crackling i thought it must have just been the leads before my power amp. but then it just stopped...and only 2 speakers worked. so i figured that one of the speakers has gone open circuit, i took it out of the cab to swap it with another 10 speaker that i got for $20, lol and the cab sounds great again. but what i want to find out is wether the speaker has blown from overpowering it or if its faulty...i know its gone open circuit, and when i gently push on the cone it moves smoothly, but when i gently shake the speaker or turn it upside down and back upright the is something ratteling in the magnet, so maybe the coil has come away from the base of the cone...would this be a manufacturing fault or is it my fault from overpowering??