DS18 X4 Ultra-Compact Class D 4-Channel Amplifier | 4 x 70W RMS @ 4 Ohms | 1320W Max 

Don't let its size fool you. The DS18 X4 is an ultra-compact Class D 4-channel amplifier engineered to deliver impressive full-range power while fitting into installation spaces where traditional amplifiers simply won't fit.

Producing up to 140 Watts RMS x 4 at 2 Ohms, 70 Watts RMS x 4 at 4 Ohms, or 220 Watts RMS x 2 bridged at 4 Ohms, the X4 is an ideal solution for upgrading factory speakers, powering component systems, or adding clean amplification to custom installations without sacrificing valuable space.

Built with advanced Class D technology, a four-layer PCB design, premium surface-mount components, and Audio Precision verified sound quality, the X4 combines efficiency, reliability, and performance into one of the most compact amplifiers in the DS18 lineup.

Why You'll Love It

✔ Ultra-Compact chassis fits where larger amplifiers can't

✔ Delivers 140 Watts RMS x 4 @ 2 Ohms

✔ Efficient Class D design for clean, reliable performance

✔ Bridgeable to 220 Watts RMS x 2 @ 4 Ohms

✔ Excellent for factory audio upgrades and custom installations

✔ Four-layer PCB design improves durability and efficiency

✔ Audio Precision verified sound quality

✔ Advanced protection circuitry helps safeguard your equipment

✔ Ideal for cars, trucks, Jeeps, motorcycles, and powersports applications (installed in protected locations)

Perfect For

• Hidden amplifier installations

• Under-seat mounting

• Behind-dash installations

• Classic and restoration vehicles

• Trucks

• Jeeps

• Motorcycles

• UTVs and Side-by-Sides (protected sealed installation)

• Compact custom audio systems

• Factory radio upgrades

Product Overview

The DS18 X4 was engineered for enthusiasts who need quality amplification without the space requirements of a traditional amplifier. Its ultra-small footprint makes it possible to install clean, efficient power in vehicles where every inch of available space matters.

Despite its compact size, the X4 delivers impressive RMS power capable of driving aftermarket coaxial speakers, component systems, and high-performance midrange speakers with excellent clarity and dynamic range. Advanced Class D circuitry helps maximize efficiency while minimizing heat, making it an outstanding solution for everyday use and custom installations alike.

Constructed with premium surface-mount technology and a four-layer PCB, the X4 is built for long-term reliability while maintaining a remarkably small footprint. Audio Precision verified sound quality ensures dependable performance that enthusiasts can appreciate.

Whether you're restoring a classic vehicle, upgrading a factory sound system, building a motorcycle audio system, or designing a hidden custom installation, the DS18 X4 provides powerful, efficient performance without demanding valuable installation space.

Ideal Applications

The DS18 X4 is an excellent choice for customers looking to add quality amplification while keeping their installation compact and discreet.

It performs exceptionally well in:

• Factory speaker upgrades

• Component speaker systems

• Four-speaker audio systems

• Hidden amplifier installations

• Under-seat installations

• Trucks and SUVs

• Jeep audio builds

• Motorcycle audio systems

• UTV and Side-by-Side builds (protected mounting)

• Classic car restorations

• Compact custom audio systems

Its combination of clean RMS power and ultra-compact dimensions makes it an ideal solution when installation flexibility is just as important as performance.

Key Features

• Ultra-Compact Class D 4-Channel Amplifier

• 1320 Watts Max Power

• 140 Watts RMS x 4 @ 2 Ohms

• 70 Watts RMS x 4 @ 4 Ohms

• 220 Watts RMS x 2 Bridged @ 4 Ohms

• Bridgeable 4-Channel Design

• Four-Layer PCB Construction

• Premium Surface-Mount Technology

• Audio Precision Verified Sound Quality

• Efficient Digital Circuit Design

• Advanced Protection Circuitry

• Compact Installation-Friendly Chassis

Technical Specifications

Brand: DS18

Series: X Series

Model: X4

SKU: X4

Amplifier Type: 4-Channel Full-Range

Amplifier Class: Class D

Channels: 4

Peak Power: 1,320 Watts

RMS Power @ 4 Ohms: 4 × 70 Watts

RMS Power @ 2 Ohms: 4 × 140 Watts

Bridged RMS Power @ 4 Ohms: 2 × 220 Watts

Minimum Impedance: 2 Ohms Stereo / 4 Ohms Bridged

Circuit Design: Class D Digital

Construction: Four-Layer PCB with Surface-Mount Components

Audio Verification: Audio Precision Tested

Protection Features: Thermal, Overload & Short Circuit Protection

Bridgeable: Yes

Application: Full-Range Speaker Systems

What's Included

• (1) DS18 X4 Ultra-Compact Class D 4-Channel Amplifier

• Installation Hardware

• Owner's Manual

What This Amplifier Powers Best

The DS18 X4 is engineered to deliver clean, efficient power for a wide variety of full-range speaker systems while fitting into installation spaces where traditional amplifiers simply aren't practical.

It is an excellent choice for:

• Four aftermarket coaxial speakers

• Four component speaker systems

• Front stage plus rear fill audio systems

• High-performance OEM speaker upgrades

• Motorcycle audio systems

• Jeep audio systems

• UTV and Side-by-Side builds (protected installation)

• Classic vehicle restorations

• Hidden amplifier installations

Its combination of compact size and impressive RMS output makes the X4 an outstanding solution for customers who want significantly better sound quality without sacrificing valuable installation space.

Installation Notes

One of the X4's greatest strengths is its ultra-compact chassis, allowing it to be installed in locations that larger amplifiers simply cannot accommodate.

Popular installation locations include:

• Under front seats

• Behind rear seats

• Behind dashboards

• Inside center consoles

• Under cargo floors

• Custom amplifier racks

• Motorcycle saddlebags and fairings (protected locations)

For the best performance, use high-quality OFC power and speaker wire, properly adjust amplifier gain, and configure the crossover settings to match your speakers. Careful tuning helps maximize clarity while protecting both the amplifier and connected speakers.

Pro Audio Center Tip

Adding an amplifier isn't just about increasing volume—it's about giving your speakers the clean power they need to perform their best.

Even factory replacement speakers often benefit from dedicated amplification, producing cleaner vocals, stronger midbass, and improved overall detail when driven with adequate RMS power. The X4 is an excellent way to achieve those improvements without requiring a large amplifier or extensive installation space.

Build Your System

Complete your installation with:

• OFC amplifier wiring kit

• Premium RCA interconnects

• High-quality speaker wire

• Sound deadening material

• Vehicle-specific speaker adapters

• Component or coaxial speaker upgrades

• DSP or line output converter for factory radio integration

Expert Recommendation from Pro Audio Center

The DS18 X4 is one of our favorite amplifiers for customers who need maximum installation flexibility without giving up meaningful performance.

Its ultra-compact footprint opens installation possibilities that simply aren't practical with many traditional amplifiers, making it an excellent option for classic cars, trucks, Jeeps, motorcycles, and custom builds where available space is limited.

For customers looking to dramatically improve speaker performance while keeping their installation clean and discreet, the X4 delivers an outstanding combination of efficiency, reliability, and real-world usability.

Why Buy From Pro Audio Center?

At Pro Audio Center, we believe the best amplifier isn't necessarily the largest one—it's the one that best fits your system and your vehicle.

That's why we focus on helping customers choose equipment that complements their installation goals, whether you're building a high-performance daily driver, restoring a classic vehicle, or creating a space-conscious custom installation.

Every product we offer is selected with real-world performance and long-term reliability in mind, so you can shop with confidence knowing you're getting equipment we would proudly install ourselves.

Frequently Asked Questions

How much RMS power does the DS18 X4 produce?

The X4 delivers:

• 4 × 140 Watts RMS @ 2 Ohms

• 4 × 70 Watts RMS @ 4 Ohms

• 2 × 220 Watts RMS Bridged @ 4 Ohms

Can I bridge this amplifier?

Yes. The X4 can be bridged to provide 220 Watts RMS × 2 @ 4 Ohms, making it suitable for higher-powered speaker applications.

Is the X4 a good amplifier for factory speaker upgrades?

Absolutely. The X4 is an excellent choice for customers upgrading factory speakers or adding aftermarket component speakers while retaining a compact installation.

Can I install the X4 under a seat?

In many vehicles, yes. Its ultra-compact chassis makes it ideal for under-seat mounting, behind interior panels, or other tight installation spaces. Always verify available clearance before installation.

Is this amplifier suitable for motorcycles and UTVs?

Yes, provided it is installed in a protected location away from direct exposure to the elements. The X4's compact size makes it a popular choice for motorcycles, UTVs, and other space-constrained applications. For installations requiring full weather resistance, consider a dedicated marine-grade amplifier.

Is the X4 a good amplifier for everyday use?

Yes. The efficient Class D design, compact footprint, and clean RMS power make the X4 an excellent amplifier for daily-driven vehicles where improved sound quality and installation flexibility are top priorities.