We do a fair amount of these cool amplifiers, and just put one in the other day, so I figured I'd tell you all about it!
A typical OEM (or factory) audio system has an amplifier that puts out 7-10 watts (rms) into each of the 4 channels. This works fine for the sub-standard speakers the car comes with. We want better than that! If you replace the radio with an aftermarket radio, this boosts the power up to about 16-18 watts (rms) per channel. This makes a noticable improvement in the sound. This cool Sony amplifier boosts the power up to 45 watts (rms) per channel! Thats when you're cooking with fire.
Another awesome benefit of this amplifier, is it is so small, it can be hidden behind the radio, or dash panels. No usable space in the vehicle is taken up. It also does not require any heavy gauge wiring kits (which can be expensive).
The XM-S400D packs a lot of punch for its $149 price tag. Contact our staff with any questions.