Aluminum vs. copper voice coil wire

a defect often encountered with square aluminium coil wire:

if a driver suddenly fails, inspect the solderings between coil wire (Al) and the souple litz wire (Cu) towards the speaker connections.

Nothing wrong with the speaker, mostly a bad soldering.

Inspect it at the back of your speaker, soldering is mostly covered with some (black) glue.

Copper wins in power and a life time longer over aluminum

the only real fact about aluminum is that it is much cheaper and has a much lower temp handling in the voice coils. big name brands and cheap walmart brands now try to use aluminum because to make a subwoofer that will for sure brake.. will make money by having to buy a new one or pay to fix it. in that process they have made you think it was a good sub powered by a 5000 watt amp (maybe if you had 2000 volts @ 99.9% thd) 400-600 watts rms "real world wattage". replace the aluminum coils with a thicker copper wire and fill that big motor gap.. you will see the difference over a life time of heavy use and seeing the subwoofer 20 plus years later. "like some older JL subs only", and some others etc... Amps today that are smaller circuits with machined boards. they will never be able to make it more that 5 years max with limited use. the internal parts are made to dissipate heat that's why your amps should be large filled with large components.