So i've got rid of the useless Bose sub, and upgraded with a rather lovely JL Audio W3. I bought this through the internet recently and the item was new. I've wired in an Apline amp, and obviously the whole lot is running through an aftermarket (Pioneer) headunit. Now the issues, i'm getting loads of interference through the head unit, hissing, whistling, buzzing when the lights/indicators are used. I'm aware that this is likely to be the ground, though i've yet to find a decent earthing point either. Main issue though, the sub works well, though makes a weird rattling noise, at all volumes (almost sounds like a screw has been left on the cone and is rattling about). When pounding out serious volume the sub seems fine, though the rattling is still audible. The cone is still well attached to the basket and there is no obvious issues. I've tried amping another sub, which worked normally, does this sound like a terminal problem?