




Kenwood Excelon X503-1
Mono subwoofer amplifier — 500 watts RMS at 2 ohms
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Kenwood Excelon X503-1 Class D Mono Subwoofer Amplifier
The Kenwood Excelon X503-1 is a compact, high-performance mono Class D amplifier that delivers up to 500W RMS at 2Ω. It features a variable low-pass filter, infrasonic filter, bass boost, and a wired remote level control—engineered to provide clean, powerful bass in tight installation spaces.
| Key Features | |
|---|---|
| RMS Power @ 4Ω | 300W |
| RMS Power @ 2Ω | 500W |
| Max Power | 1,000W |
| Low-Pass Filter | 50–200 Hz, 24 dB/octave |
| Infrasonic Filter | 25 Hz, 24 dB/octave |
| Bass Boost | 0–18 dB @ 40 Hz |
| Install-Friendly | All connections on one side; compact chassis |
| Build | Shielded output coil, premium components for low distortion |
| What’s in the Box |
|---|
| 1x X503-1 mono amplifier (2 × 30A fuses pre-installed) |
| 1x 7" speaker-level input harness |
| 1x Wired remote level control |
| 1x 19.5' remote level control cable (RJ-14) |
| 1x Hex nut |
| 1x Flat washer |
| 4x 1/2" mounting screws |
| 2x Allen keys (4 mm & 2.5 mm) |
| 1x Instruction manual & warranty information |
| Technical Specifications | |
|---|---|
| Frequency Response | 20 Hz – 200 Hz |
| Signal-to-Noise Ratio | 100 dB (ref. rated power into 4Ω) |
| Input Sensitivity (RCA) | 0.2V – 5.0V |
| Speaker-Level Input Sensitivity | 4.0V – 12.0V |
| Fuse Rating | 2 × 30A mini-ATC |
| Dimensions (W × H × D) | 8-3/8" × 2-1/16" × 5-7/8" (≈213 × 53 × 149 mm) |
| Operating Voltage | 11–16V DC (14.4V nominal) |
| Current Draw | 28A (approx.) |
| Warranty | 2 Years (parts & labor) |

Kenwood Excelon X503-1 Excelon Series 500W RMS at 2-Ohms, Class-D Mono Subwoofer Amplifier (Wired Remote Control Included)
The Kenwood X503-1 is a compact mono subwoofer amplifier designed to deliver powerful, high-quality sound while fitting seamlessly into your vehicle. Capable of producing up to 1000 watts of output, it elevates your music with deep, dynamic bass and clear, distortion-free audio. Features like the wired remote control allow quick volume adjustments, while automatic turn-on with signal sensing ensures effortless integration with your system. Built-in filters and bass boost give you control over your sound, making it easy to tailor your listening experience to perfection.
Engineered for superior audio performance, the X503-1 includes a magnetic-shielded output coil to reduce noise, high-quality capacitors for crystal-clear sound, and an infrasonic filter for deep, efficient bass. Every component is designed to provide accurate, rich audio while maintaining consistent performance even at high output levels.
Installation and operation are simple and convenient, with gauge-style terminals for secure connections, one-sided terminals for easy setup, and a 7" speaker-level input harness for seamless integration with factory-installed receivers. The included wired level control allows effortless adjustments to your subwoofer, giving you complete command over your audio system without compromising space or aesthetics.
Key Features
– Mono Subwoofer Amplifier with Compact, Space-Saving Design
– Maximum Output Power: 1000 Watts
– Automatic Turn-On with Signal Sensing for Seamless Integration
– Wired Remote Level Control with 19.5' Cable for Convenient Adjustments
– Magnetic-Shielded Output Coil for Noise Reduction
– High-Quality Capacitors for Clear, Distortion-Free Audio
– Infrasonic Filter for Deep and Efficient Bass
– Built-In Filters and Bass Boost for Customizable Sound
– Gauge-Style Terminals and One-Sided Connections for Easy Installation
– Includes 7" Speaker-Level Input Harness, Hex Nut, Flat Washer, Four 1/2" Screws, Two Allen Keys (4mm & 2.5mm), Warranty Information, and Owner’s Manual
What's Inside?
- Mono subwoofer amplifier (2 installed 30A mini-ATC fuses)
- 7" Speaker-level input harness
- Remote level control
- 19.5' Remote level control cable (RJ-14 connectors on both ends)
What Others Are Saying
Eddie was great - SDCS installed a new head unit in my 2019 4Runner. He was honest in his opinions regarding the options I was considering. Pricing was also good - he was able to reuse some of my existing installation kit so I saved a bit of $$.Installation was clean and fast and he took the time to walk through the features before I left. Highly recommend!!
I had a great time at this shop! The staff really knows their stuff and took the time to explain the different options without pressure. Installation was quick, clean and professional. Everything looks factory and sounds amazing. The prices were fair and customer service was above and beyond. I highly recommend this place if you're looking for quality car audio and excellent service.
Those guys are really professional! I had a new Alpine floating head unit installed in my 2008 Mercedes, and it feels like a brand-new car. The installation was super clean. At first, the sound wasn’t the same as the factory stereo, but Kevin tuned it to be just as good—if not better—without adding any new amps. They even used my factory GPS antenna so I don’t have extra wires hanging out. On top of that, they matched the online price. Big thanks to Kevin and Eddie—highly recommended!
Kevin was awesome, he took his time and explained everything to me. I went in initially for a dash cam install and then decided to get a sub and amp installed as well. Both turned out great and will be returning if I need more work done.
Came In not knowing what to expect when suddenly my stereo stopped working. Spoke with Kevin in the front and after a VERY fast diagnosing they discovered my wiring was incorrect. After only about 45 minutes total being in the store I was on my way to the beach with a working stereo again! Thank you so much SDCARSTEREO
Highly recommend Kevin and the team at San Diego Car Stereo for any issues with aftermarket stereos. I bought a car with an aftermarket stereo and AC unit that wasn’t working properly—specifically, the heat wasn’t functioning due to an improper setup. I had several people look at it with no luck, and even the dealership basically refused to help because it was an aftermarket install. I came to Kevin and his team over the holidays feeling pretty defeated, but he was confident he could get the heat working before I headed back to a Colorado winter. Sure enough, he got it done.
FAQ
Do products purchased from San Diego Car Stereo come with a warranty?
Yes, all products come with a 1-year manufacturer warranty unless otherwise stated. This covers any defects excluding physical damage.
Are these products brand new?
Yes, every product we sell is 100% brand new, unused, and comes in original manufacturer packaging unless clearly marked otherwise.
Do you offer installation services?
Yes, we offer professional installation services at both of our San Diego Car Stereo locations. Our expert technicians have over 50 years of combined experience to install all of your car, marine, or offroad audio needs. Stop by or give us a call to schedule an appointment to get a quote in person.
