Thule seems to think their design approach meets these criteria nicely and, best of all, does so in a reasonably-sized efficient package that likely won't invoke a hernia to the installer. Their ...

The Sherbourn PA 7-350 is truly a beast of an amp. It is the size of a receiver (17” wide by 18.5” deep by 9.625” tall) and tops 100 pounds. Yeah, that's one heavy box full of speaker-melting power.