Check the listing for details. Sony XMS400D 45W x 4 Compact Car Amplifier. Condition: New. Listed at 148.00 USD. Product highlights4-channel car amplifier 45 watts RMS x 4 at 4 ohms (non-bridgeable, only works with 4- to 8-ohm speakers) CEA-2006 compliant switchable high-pass filter on front channels (120 Hz at 12 dB/octave) switchable low-pass filter on rear channels (120 Hz at 12 dB/octave) preamp and speaker-level inputs fuse: 15A x 1 12-gauge power and ground leads recommended — wiring and hardware not included with amplifier dimensions: 7-1/4"W x 1-1/2"H x 2-1/2"D warranty: 1 year What's in the box4-Channel amplifier (15A ATM fuse installed) 8" RCA input harness (10-pin Molex plug) 39" Speaker-level input harness (10-pin Molex plug) 40" Power/speaker output harness 2 Self-tapping screws (3/4" length) 2 Mounting tabs 2 Bracket screws (1/8" diam.x 1/4" length) Operating Instructions European Guarantee Information Document About this itemWritten by Crutchfield's Buck Pomerantz Seriously small amp Sony knows that many vehicles just don't have space for a big amplifier, so they've created the XMS400D 4-channel amp. This tiny powerhouse will blow your mind — blasting your front and rear speakers with 45 watts RMS each from a chassis that's the size of a big candy bar. High- and low-pass filters You can't bridge this amp, but you can use the onboard switchable high- and low-pass filters to run small subs with the rear channels and full-range speakers with the front channels. The amp will accept preamp or speaker-level signals, so it'll hook up to just about any system. Looking for bass Got a Sony receiver with Mega Bass but no subs yet? This amp connects easily to your system, and the extra power will make your speakers sing. If you've got aftermarket speakers in your car, turn on Mega Bass and you'll hear a night-and-day difference in the bass.