M500/3: 3 Ch. Class D Full-Range Marine Amplifier, 500 W
SKU # 98277

M500/3
3-Channel Class D Marine System Amplifier, 75 W x 2 @ 4 Ω + 300 W x 1 @ 2 Ω - 14.4V
This compact amplifier is ideal for a simple audiophile-grade, subwoofer / satellite system. With the M500/3, you can drive a pair of quality component speaker systems with plenty of clean power, while also delivering a stout 300 W to a subwoofer system. The breakthrough that makes this much power possible in such a small chassis is our NexD™ switching design.
The M500/3 includes a 12 dB / octave high-pass filter for its main channels, plus a variable slope low-pass filter for its subwoofer channel. Both filters offer continuously variable cutoff frequency selection from 50-500 Hz.
This marine amplifier features white and gray powder-coat finishes, a gasketed cover for the controls and stainless steel hardware for durability in the marine environment.
Rated Continuous (RMS) Power @ 14.4 V
Main Channels @ 4 Ω | 75 W RMS x 2 |
Main Channels @ 2 Ω | 100 W RMS x 2 |
Main Channels - Bridged @ 4Ω | 200 W RMS x 1 |
Subwoofer Channel @ 4 Ω | 180 W RMS x 1 |
Subwoofer Channel @ 3 Ω | 240 W RMS x 1 |
Subwoofer Channel @ 2 Ω | 300 W RMS x 1 |
Subwoofer Channel @ 1.5 Ω | N/A |
Rated Continuous (RMS) Power @ 12.5 V
Main Channels @ 4 Ω | 60 W RMS x 2 |
Main Channels @ 2 Ω | 90 W RMS x 2 |
Main Channels - Bridged @ 4Ω | 180 W RMS x 1 |
Subwoofer Channel @ 4 Ω | 180 W RMS x 1 |
Subwoofer Channel @ 3 Ω | 240 W RMS x 1 |
Subwoofer Channel @ 2 Ω | 300 W RMS x 1 |
Subwoofer Channel @ 1.5 Ω | N/A |
General Specifications
Frequency Response (Main Channels) | 12 Hz - 22 kHz (+0, -1dB) |
Frequency Response (Subwoofer Channel) | 10 Hz - 1 kHz (+0, -1dB) |
S/N Ratio, referred to highest rated power (Main Channels) | >104 dB below rated power (A-weighted, 20 Hz - 20 kHz noise bandwidth) |
S/N Ratio, referred to 1 W | >84 dB (A-weighted, 20 Hz - 20 kHz noise bandwidth) |
Damping Factor @ 4 Ω | >120 / 50 Hz |
Damping Factor @ 2 Ω | >60 / 50 Hz |
THD+N @ Rated Power (Main Channels) | <1% @ 2 Ω per Ch. |
THD+N @ Rated Power (Subwoofer Channels) | <1% @ 2 Ω per Ch. |
Input Voltage Range @ RCA Inputs | 100 mV - 4 V RMS |
Min.Copper Power / Ground Wire Gauge | 4 AWG wire |
Fuse Rating | 50 A (AFS, AGU or MaxiFuse™) |
Signal Processing
Filter Mode(s): Channels 1 & 2 (front) | High-Pass only |
Filter Slope(s): Channels 1 & 2 (front) | 12 dB/octave |
Filter Frequency Range: Channels 1 & 2 (front) | 50 Hz - 500 Hz |
Filter Mode(s): Channels 3 & 4 (rear) | N/A |
Filter Slope(s): Channels 3 & 4 (rear) | N/A |
Filter Frequency Range: Channels 3 & 4 | N/A |
Filter Mode(s): Subwoofer Channel | Low-Pass only |
Filter Slope(s): Subwoofer Channel | 12/24 dB/octave |
Filter Frequency Range: Subwoofer Channel | 50 Hz - 500 Hz |
Detented, Calibrated Filter Freq. Potentiometers | Yes |
Filter Defeat Function | Yes |
Infrasonic Filter: Subwoofer Channel | none |
Remote Level Control | Optional (HD-RLC) |
Remote Level Modes | Sub Ch. or All Channels |
Channel Input Mode Switch | Yes (2/4 ch.) |
Pass-Through Preamp Output | Buffered |
Source Channel Selection for PreOuts | Yes (1&2/Sum/Sub) |
Physical Specifications

Height (H) | 2.05 in / 52 mm |
Width (W) | 8.52 in / 216 mm |
Depth (D) | 7.09 in / 180 mm |
Net Weight | 4.8 lb / 2.18 kg |

NexD™ Switching Technology
Summary:
NexD™ amplifier technologies produce exceptional audio quality, unsurpassed total efficiency and high power from very compact amplifier designs.
Detailed Information:
Beginning with the original 'Slash' subwoofer amplifiers, JL Audio has been at the forefront of Class D amplifier design. Our NexDTM switching technology stems from our Class D expertise to deliver outstanding fidelity and efficiency, leading to compact amplifiers that deliver high power and exceptional value.
Let's get a little nerdy... A traditional PWM switching amp design uses a fixed switching frequency and varies the pulse width based solely on the audio input signal to the pulse modulator. This basic approach assumes some ideal conditions, like a rock-steady power supply, that do not necessarily occur in a real, in-car installation. Power supply sag with signal causes distortion at all power levels with these designs, even well below clipping. The cure for this is feedback (a corrective signal sent back to the input side), but this becomes impractical as the audio frequency increases, making it a good solution for band-limited (subwoofer) amps, but not for full-range amplifiers.
Taking the above into account when designing the NexD™ subwoofer amplifiers, we have taken the simple fixed PWM approach and enhanced it with a very high switching frequency: 240 kHz, which is about 4x higher than most Class D subwoofer amplifiers. This pushes the amplifier's bandwidth to at least 500 Hz with minimal distortion and improves efficiency, while keeping typically bulky circuity more compact. Your subwoofers will reward you with tight, rock-solid bass performance.
For the full-range NexD™ amplifiers and channels we applied a variable, ultra-high speed version of the NexD™ technology (switching at well over 400 kHz). In these designs, a self-oscillating modulator with "feed-forward" sends information about the instantaneous power supply voltage to the modulator, combining this with the input signal to cancel out any distortion due to supply voltage fluctuation. This reduces distortion prior to applying feedback, simplifying the overall feedback loop design.
The bottom line is simply great audio: clean, powerful and reliable.

Advanced Rollback Protection
Summary:
JL Audio's exclusive Advanced Rollback Protection circuit monitors the amplifier's thermal condition and adjusts amplifier operation to eliminate annoying amplifier shut-down events.
Detailed Information:
Should a JL Audio amplifier equipped with Advanced Rollback Protection reach an unsafe operating temperature, a special circuit rolls back peak power output, without changing gain, until the amplifier cools down to a safe operating temperature. The condition is generally indicated by a red “Thermal” or “Status” LED state. On VXI amplifiers, the LED ring will flash red. Once the amplifier cools down, the circuit restores full peak power output and the indicator reverts to its normal state. The operation of Advanced Rollback Protection is inaudible in most cases, but it ensures that your music keeps on playing, even under the most demanding conditions.
Download Product Manual: M500-3 Manual
Find the answers to many common questions:
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U.S.A. Warranty Information - Marine Amplifiers and Electronics
JL Audio Marine Amplifiers and Electronics are warrantied against defects in materials and workmanship for Two (2) Years from purchase date. JL Audio will, at its discretion, repair or replace any products that exhibit defects in materials and/or workmanship during the warranty period.
Please hold on to your sales receipt! All warranty service requires original sales receipt documentation. The warranty only applies to the original purchaser from an authorized retailer.
Note: Products purchased from unauthorized dealers are not covered under warranty.
Warranty Limitations
The following is not covered under JL Audio's warranty program:
1. Product with defaced, altered or removed serial numbers (no valid, legible serial number = no warranty).
2. Product owned by anyone other than the original purchaser from an authorized JL Audio dealer. (The warranty is not transferable and will not apply to products purchased from unauthorized dealers.)
3. Product that has been physically abused (run over by a car or beat with a hammer, for example).
4. Product that has not been installed according to the instructions in the owner's manual
5. Product in which repair and/or modification has been attempted by unauthorized parties
6. Product damaged cosmetically due to improper handling or normal wear and tear
7. Product damaged in an accident, due to criminal activity (attempted theft, gunshot damage, etc.) or by 'acts of God' (flooding, lightning, locusts, etc.)
8. Custom finishes or other cosmetic treatments applied to products. (JL Audio will not be responsible for restoring or maintaining any custom finishes)
9. Installation and shipping costs associated with removing, re-installing or shipping the product to JL Audio for warranty service
Ask your dealer for details on warranty limitations.
If you need Service on your JL Audio Product:
All warranty returns should be sent to JL AUDIO freight prepaid through an authorized JL AUDIO dealer and must be accompanied by proof of purchase (a copy of the original sales receipt.) Direct returns from consumers or non-authorized dealers will be refused unless specifically authorized by JL AUDIO with a valid return authorization number. Warranty expiration on products returned without proof of purchase will be determined from the manufacturing date code. Coverage may be invalidated as this date is previous to purchase date. Return only defective components. Non-defective items received will be returned freight-collect. Customer is responsible for shipping charges and insurance in sending the product to JL AUDIO. Freight damage on returns is not covered under warranty. Always include proof of purchase (sales receipt).
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– 2011 Reader's Choice Awards, Powerboat Magazine
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