The Monsoon doesn't even sound as good as my coaxial Infinity Kappa's, save some money for real aftermarket speakers and an amplifier, you'd be disgracing the clean output of your HU by sending the signal to the Monsoon, just so it can make it sound crappy.

Really though, listen to a stock system and then a Monsoon. There's definitely an improvement. Then listen to the Monsoon followed by a real system, even bigger improvement.