While looking for something else entirely, I came across this ad for the
Jackhammer subwoofer.
This goes in your car.
Recommended power to drive this thing is 3000-6000 watts RMS. 6000 watts is a little over 8 horsepower. For a subwoofer. That's more than your starter on your engine draws. That's also on par with a movie theater sound system.
If you were going to wire up an amplifier that would drive this in your house, you'd need a dedicated 230V/30A line just for the subwoofer amplifier.
Price tag on this baby is $7500. Not including the amplifier. And yes, the same company makes amplifiers more than capable of driving it: their top end model can handle 9000 watts RMS. It requires 0-gauge copper stranded cable, along with "stiffening" capacitors, and I would bet it needs a heavy-duty alternator as well-- it would smoke a regular alternator in pretty short order.
The website mentions that they have a slightly different model for use in "competition".
I can feel my brain turning to jelly.
Edit: Indeed, after looking at the user manual, the recommended electrical system upgrade requires an additional heavy-duty alternator and multiple batteries-- the base diagram has three batteries-- and that's just for the subwoofer.