I just installed a viper 1100.5 amp. I have 1 12" kicker connected to the sub side, the 4 channel side of the amp connected to a 10" kicker l7 with both voice coils connected separetly. I have both subs mounted backwards so that the magnets show, and until now they worked fine, the 10" had a minor air leak, so in between amp installs I resealed the 10. After hooking the viper up, my 10" was rattling I noticed. I realized it was played voice sounds with very little bass. After correctly crossing it over, it still rattled. I took the sub off the box and tested it free air in my car via the sub channel and it still rattles. The 12" works fine on both 2 channel and mono operation. I'm not sure if it's blown or the surround is damaged or if it will make that sound due to it being free air during the troubleshoot. I bought it as a refurb. The surround does not have any visible damage, I went over it with a fine tooth comb. Any help would be appreciated. Thanks