My system has plenty of power. Who needs an amp?

You might think you don't need an amp because you have a 400-watt system in your car, or because your new stereo puts out 50 watts a channel. But those are peak wattage ratings, which may boil down to 15 or 20 watts per channel, using the more realistic RMS rating. An amp sends your speakers the power they need to deliver your music with clarity and impact, whether you're using factory speakers or high-performance components. And low-frequency reproduction requires lots of power, so an amp is an absolute must if you're adding a sub to your system.

Super-slim profile, big-time power

Kenwood's Excelon XR400-4 4-channel amplifier adds clarity and punch to your car's audio system, as it powers each of your front and rear speakers with 75 watts RMS. As your system changes, you can also use the XR400-4 in 2-channel mode to drive a couple of subs with up to 200 watts RMS each. The XR400-4 can fit in many different places in your car because of its incredibly low profile — it's under 1-1/2" tall. And Kenwood protects this sharp-looking amp with its Excelon 2-year warranty.

Designed for optimum efficiency

Kenwood packed this amp with space-saving features. Class D technology reduces the size of the power supply, while the internal heatsink is tilted to reduce height without compromising the amp's cooling system. Recessed power and speaker wire terminals help to further reduce the amp's footprint, protect the connections, and give your installation a neat, professional look.

Controls for the best sound — bi-amp capable

You can contour the sound with high- and low-pass filters so your speakers play efficiently and sound their best. The front and rear channels have separate gain and filter controls so you can adjust for different types of speakers. The XR400-4 also gives you the ability to "biamp" your system, amplifying the tweeters and woofers separately for greater power and control over the sound.