The Kenwood KAC-6404 is a versatile, affordable amplifier that is perfect for anyone who wants to upgrade their systems sound, but is on a budget. Rated at 40 watts x 4, it will bring your front and rear full range speakers to life. This amp is also versatile enough to run your whole system. You can run one pair of full range speakers off of the front channels and bridge the rear channels to run subwoofer or two in mono. Since this amp has adjustable high-pass and low-pass filters, you can maximize the performance of the system no matter what configuration you set the amp up in. This amp would make nice upgrade to almost any standard car stereo system, OEM or aftermarket.