People will talk ish in this thread about a 6" coil motor but the 6" WILL be advantageous in SPL. If DD is smart enough to do it then they will be getting more attention if/when it goes down. Music? Maybe insanely loud music from a 22 or something with a heavy enough cone for it, ALOT of power, and thin coil. The motor will only matter if the top plate is beefy enough otherwise it is a paperweight.
It would probly take 40k give or take, but that is Insane power. Now you know why 16v setups are starting to be more popular because the higher the voltage the less current(batts and alt) one likely needs given a certain amount of power.