Sony XMS400D 4-Channel Car Amplifier – 45W x4, Class-D (Black)

Upgrade your car audio with the Sony XM-S400D

Transform how music sounds on the road with the XM-S400D 4-channel amplifier. Its compact footprint fits neatly under a seat or behind the dash, while Class-D efficiency helps keep power draw reasonable. Delivering up to 45 watts per channel at 4 ohms, this amp has the potential to reveal more detail and impact from your speakers than a basic head unit alone.

Power and precision you can rely on

The XM-S400D is built to deliver clean, linear output across a broad range. Its 20 Hz–20 kHz frequency response supports everything from deep, punchy bass to bright, articulate highs, helping your music feel more balanced. A compact chassis preserves cabin space, so you can install it without sacrificing interior layout or storage.

Thanks to efficient Class-D technology, the amp can provide strong performance with reasonable heat and power management, making it suitable for everyday listening in a wide range of vehicles.

Built-in tuning, protection, and easy setup

Integrated LPF and HPF filters let you shape bass and treble directly from the amplifier, aiding smoother transitions between speakers and any sub or enclosure you’re using. A dedicated protection circuit reduces the risk of speaker damage, and an indicator keeps you informed about operating status for peace of mind.

Flexible connections for real-world installs

The XM-S400D accepts both high-level and low-level inputs, and includes Hi-level Sensing Power On to work with many factory head units as well as aftermarket systems. This flexibility can simplify wiring in diverse vehicle layouts and help your install stay tidy and reliable.

What you might notice in practice

• Clearer vocals and instrument detail with balanced midrange performance
• Defined highs without grit, thanks to precise high-pass and low-pass control
• More controlled bass and even power delivery across channels
• A compact amplifier that preserves dash and under-seat space

Ideal uses and setup ideas

• Upgrading factory or aftermarket head units for a fuller sound stage
• Installing in tight dashboards or under seats where space is at a premium
• Pairing with compatible speakers for easier tuning and a balanced system

Note: frequency response and power figures are typical under specified loads. Real-world results depend on your speaker combo and head unit configuration. The XM-S400D is designed to broaden your sound possibilities without dictating a particular outcome.