About: Sony XMS400D Compact 4-Channel Car Amplifier 

Continuous power output of 45 W per channel (at 4 Ω)

Enjoy powerful audio throughout the entire car, thanks to the 180 Watts total continuous system power (45 W X 4 RMS).

Class-D Technology

The Class-D Technology is a method to convert and amplify music signals with MOSFETs to high speed pulse signals. Furthermore, it features high efficiency and low heat generation.

Compact Design

Small enough to fit almost anywhere. Dimensions are 6.5in L x 1.5in H x 2.5in W. 

Built-in LP (low-pass) filter and HP (high-pass) filter

The XMS400D has a 120Hz high-pass filter for the front channels and a 120Hz low-pass filter for the rear channels.

Protection circuit and indicator provided

This amplifier is provided with a protection circuit that operates in the following cases: When the unit overheats, When a DC current is generated, When the speaker terminals are short-circuited. If a protection circuit is activated, the POWER/PROTECT indicator will flash.

High level or low level input connection

The XMS400D has the ability to connect to a source unit by high (speaker) level or low (RCA) level input. 

Hi-level Sensing Power On

If you have the factory original or some other car audio unit without a remote output for the amplifier, connect the remote input (REM) wire of the supplied power connection cable to the accessory power supply. With the high level input connection, the car audio unit can also be activated without need for a REMOTE connection.

Specifications:

• 4-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 (W x H x D): 7-1/4" x 1-1/2" x 2-1/2"