Alpine's X-Power amplifiers use the latest amp technology to play your music loud and clean without taking up much space. And these amps employ some of the same circuitry developed for Alpine's top-of-the-line PDX digital amps, so they'll bring exceptional sound to almost any ride.

The MRX-M50 mono amp puts out up to 500 watts RMS to your subwoofer, so you can fill your listening space with plenty of bass. And it'll operate safely with a 1-ohm load, making it useful in a variety of sub system installations. Onboard low-pass and subsonic filters let you get the best sound out of your setup, while a bass boost helps to fatten up the sound if you need it.

A power management system optimizes the amp's performance and keeps the music playing, even when you're pushing it hot and hard for a long time. Speaker-level inputs with an automatic turn-on feature simplify system hook-up.

Product Highlights:

  • mono subwoofer car amplifier
  • 300 watts RMS x 1 at 4 ohms (500 watts RMS x 1 at 2 ohms)
  • 300 watts RMS x 1 at 1 ohm
  • CEA-2006 compliant
  • variable low-pass filter (50-400 Hz, 12 dB/octave)
  • variable bass boost (0-12 dB at 50 Hz)
  • variable subsonic filter (5-30 Hz, 24 dB/octave)
  • optional remote level control (RUX-KNOB)
  • Class D amp with MOSFET power supply
  • preamp and speaker-level inputs
  • fuse rating: 30A x 2
  • 4-gauge power and ground leads recommended — wiring and hardware not included with amplifier
  • 9-15/16"W x 2-5/16"H x 9-1/16"D
  • warranty: 1 year
  • Our 60-day money-back guarantee

My system has plenty of power. Who needs an amp?

You might think you don't need an amp because you have a 400-watt system in your car, or because your new stereo puts out 50 watts a channel. But those are peak wattage ratings, which may boil down to 15 or 20 watts per channel, using the more realistic RMS rating. An amp sends your speakers the power they need to deliver your music with clarity and impact, whether you're using factory speakers or high-performance components. And low-frequency reproduction requires lots of power, so an amp is an absolute must if you're adding a sub to your system.

Hands-on research

What's in the box?

Download owner's manual

  • Mono subwoofer amplifier
  • Two 30A ATO fuses (installed)
  • 7" Speaker-level input harness
  • Four 3/4" Self-tapping screws
  • 2 Terminal covers
  • Four 7/16" Terminal cover screws
  • 2.5mm Allen wrench
  • Owner's manual (English/ French/ Spanish)
  • Verification Certificate
  • Warranty information
  • Customer Care Registration card

Product Research

Features
Controls
Connections

Features

MRX Amplifier Design: Class-D amplifiers boast higher efficiency, produce less heat, and draw less current than traditional Class-AB amps. The new MRX series benefits from the technology trickledown from Alpine's more expensive PDX amps, including Direct FET final outputs, thermal management processor, 6-Layer Glass Epoxy PC Board; combining to create a high-end sound quality without the bulky heat sinks required by most amps in this power class.

STAR Topology: Alpine's unique STAR (Signal Transit for Accurate Response) Circuit PCB design provides a single common ground for all amp sub-blocks, preventing ground interference and minimizing internal noise.

Power Management Processor: The multi-stage Power Management Processor continuously monitors component temperatures throughout the amplifier and decreases power output if anything gets too hot. When playing music under heavy loads for long periods, the circuit automatically reduces power output slightly at first, and then further in a second stage if necessary. This two stage approach provides an interruption free listening experience.

CEA 2006 Compliant: The MRX-M50's power ratings are measured according to the Consumer Electronics Association CEA-2006 standards. These standards allow you to accurately compare the rated power output of all CEA 2006-compliant amplifiers, even different brands. Manufacturers who adhere to the standards can display the CEA 2006 logo on their products and packaging. The power output is measured from 20 Hz to 400 Hz using a 14.4 volt power supply:

  • 4-ohm: 300 watts with no more than 0.04% THD+N
  • 2-ohm: 500 watts with no more than 0.06% THD+N
  • 1-ohm: 300 watts (no THD+N figure given)

Signal-to-Noise: When measured under CEA-2006 conditions (reference 1 watt into a 4-ohm load) the signal to noise ratio is 90 dBA. Measured at the rated power output S/N is 114 dB.

Verification Certificate: The amplifier comes with a certificate that lists the RMS power output measured from that specific amplifier. It also lists the model number, serial number, test date, and the test conditions (voltage and impedance).

Auto Turn On: When using the speaker level inputs the X-Power amplifiers automatically turn on when voltage is detected on the signal inputs, making them an easy factory system upgrade.

Low Output Impedance: With low output impedance, the MRX-M50 outputs tightly controlled bass, with a damping Factor rated at greater than 1000.

LED: The top panel LED power indicator glows blue when the amplifier is turned on.

Controls

Gain: The MRX-M50's gain is set according to the level of the incoming signal. The line-level input gain setting is continuously variable from 200 mV to 4.0V; the speaker-level input gain setting is continuously variable from 500 mV to 10.0V.

Crossover: The low-pass crossover point is continuously variable from 50 to 400 Hz and the slope is 12 dB/oct; the crossover cannot be bypassed.

Subsonic Filter: The amp also has a 24 dB/oct subsonic filter, continuously variable from 5 to 30 Hz.

Bass EQ: Bass boost can be applied to the subwoofer output; it's variable from 0 to +12 dB and centered at 50 Hz.

Connections

Power/Ground/Remote: The MRX-M50 features set-screw terminals for the Power, Ground and Remote Turn-on inputs. The Power and Ground terminals will accommodate up to 4 gauge wire (Alpine recommends 4 gauge for cable runs over 3'), the Remote Turn-on terminal will accept up to 8 gauge wire.

Speaker Output: The speaker outputs terminal is also set-screw terminals and will accept up to 8 gauge wire.

Line Input/Output: Line level RCA is the preferred input connection. The full range stereo line output allows easily adding another amp without running a second set of cables.

Speaker Level Input: Use the included speaker level input harnesses if the connected radio has no preamp outputs.

Fuses: The amp is protected by two chassis mounted 30-amp ATO fuses.

Remote Bass Control (optional): Alpine's wired remote (item number 500RUXKNOB, sold separately) offers control of the subwoofer output level from the front of your vehicle for remote bass adjustments.

Our Product Research Team

At Crutchfield, you'll get detailed, accurate information that's hard to find elsewhere. That's because we have our own in-house Product Research team — they open the box, verify contents, check the owner's manual, and record dimensions, features and specs. We stay on top of new products and technologies to help people make informed choices.

Alpine MRX-M50 Reviews

Average Customer Review:

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Great amp

Written By Trip3ace, Brookings, SD on Thursday, November 01, 2012

I have two of these little guys powering two alpine type r subs 10in subs and they sound absolutely awesome. I couldnt be more happy with my set up. Sounds very punchy.

Pros: Amazing sound quality

Cons: Over powers your subs if you dont have a amp for your speakers. Also i get a pretty bad light dim in my car at night when i bump them hard.

Alpine MRX-M50

Written By Matt C., Montpelier, ID on Tuesday, June 12, 2012

Crutchfield Customer Review (What's this?)

Have this amp powering two JL Audio WXv2 subs and it definately gets the job done! Very happy with this amp, stays cool while pounding out the bass!

Pros: Very cost efective amp, small foot print

Cons: none

Great Amplifier

Written By Mike P, Austin Texas on Thursday, May 10, 2012

Crutchfield Customer Review (What's this?)

Great Compact Amplifier - Fit Nicely in the Spact that I had designated. Amp runs cool and puts out a punch for its size. I have this amplifier pushing two 12" Alpine Type E Subwoofers in my 1999 GMC Sierra. Both Subwoofers require 250 Watts RMS @ 4ohms. I have this Mono Alpine Amp setup to Push both Subwoofers at 500 Watts @ 2ohms (Both Subwoofers receive 250 Watts RMS). Subs sound wonderful with this amp pushing them. Id recommend this Amp for those that are pushng Entry levelsubs like I am and want to max thos subs Wattage to the Highest. Great Product and very cost effective.

Pros: Small Footprint, very cost effective, Great or pushing two subs

power in a small package

Written By travis, soda springs, idaho on Tuesday, May 08, 2012

Crutchfield Customer Review (What's this?)

Great amp, pushing two 12" 250 rms 4 ohm subs ran in parallel, awesome.

Pros: Does not get hot, small, a lot of clean power

Cons: None

Great Amp

Written By Jason, Chicago,Il on Thursday, May 03, 2012

Crutchfield Customer Review (What's this?)

Great Amp, I have the Sony Xnv770 pushing this amp and the amp pushing one 12" Alpine type S in my 04Yukon Denali truck and WOW it hits hard, very detailed tight deep bass. This amp has alot of room for adjustment as well, also ordered the RUX knob with it so I can adjust the amp right at my drivers seat... Also it's small it mounted right under my back seat out of the way of everything and no one knows it's there..I give this amp 5 stars 2 thumbs up or A+++ all the way around

Great amp at the sale price

Written By Haddix, Erie, PA on Thursday, April 12, 2012

Crutchfield Customer Review (What's this?)

  • "Coolness Factor"
  • Build Quality
  • Ease of Use
  • Sound Quality
  • Value

I have this amp powering one E-series Alpine 10" subwoofer in a sealed 1.0 cu. ft. enclosure in a 2005 Jeep Liberty. In a system where the emphasis is sound quality over boom this amp performs flawlessly. I am seriously considering upgrading to a second woofer and running the amp at a 2 ohm load.

Pros: cost efficiency sound quality flexibility

Cons: at this price point none

Alpine MRX-M50 Mono Sub Amp.

Written By Keith, Andover, MN. on Tuesday, April 10, 2012

Crutchfield Customer Review (What's this?)

Alpine does it again, clean accurate heavy power for my sub, all easy to hide under my back seat. Nice to dial in your type of sound and punch.

Pros: Price per punch factor is huge, great features , cool blue light is nice touch at night.

Cons: none

Big bass from a small amp

Written By Tom's dad, Hawaii on Monday, January 30, 2012

We shopped around for a quality amp that doesn't take up much space, and one we could find at a reasonable price. This little mighty mite fit the bill. It fits under my son's passenger seat, out of sight and out of mind, but it's presence is sure felt. We had an output knob installed (Alpine as well) on the dash and it looks like it was put there at the factory. You can hear the bass from his single JL 12W6 with the knob turned all the way down. We tried turning it all the way up, but with the hatch down on the car, the sound exceeds tolerance levels. I'd swear the car could vibrate off a curb with the engine off! This amp and a good speaker box (> 1.5 cu ft interior) with a quality speaker is more than my son will every need. It's great. I'll try to remember to add to this review in a year when it's been put through its paces. Hopefully we'll never have to put Alpine's warranty to the test. So far, the MRX-M50 seems like just the amp for the job.

Pros: Small enough to fit in small places, but powerful enough to get the most of a JL 12W6 - the sound is spilling out of the car before the selection knob is turned up half way.

Cons: With an Alpine knob set to the minimum, the amp still puts out power to the sub, so there's no way to get it down to nothing, but then who'd want to do that? It's not much to look at, but if it's going below a seat, what does it matter?

Alpine MRX-M50

Written By Adam, Daphne, AL on Sunday, September 25, 2011

This amp had big shoes to fill replacing my 500.1 amp that finally quit on me after years of great sound quality and power. I did about 3 weeks worth of extensive research on different amps to run 500 RMS at 2 ohm load on a kicker solo. I ended up narrowing it down to the diamond audio 600.1 or this amp. Either amp I think would have been a great choice, but I decided to try this new design class D technology. I'm very impressed with this amp it's got plenty of power and runs cool. Sound quality is insane, has every adjustment accept a phase switch. ALPINE GREAT JOB!!!!!

Best amp for the money. Period.

Written By EvilCaddy, Calabasas,CA on Tuesday, July 19, 2011

I was a concerned that this amp would be too under powered to make my two 12inch Kicker Comps boom. Boy was I wrong.

I have a 2006 Cadillac STS. I have the Bose system which by its self sounds incredible but after adding this Alpine amp and the Kickers my car BOOOOMs. It rattles license plates two cars ahead of me at a red light.

This amp is simply awesome, takes up almost no space and has never even gotten very warm, let alone hot.

Thank you Alpine for offering an amp that can compete with show systems at a price that almost everyone can afford.

Buy this amp I promise you that you will not be sorry.

Get everything you’ll need to enjoy your new Alpine MRX-M50

You'll need an amp wiring kit to install your new amplifier, as wiring is not included.
Bring the music from your amp to your speakers.
Patch cables take the music from your stereo to the amplifier. Most amp wiring kits don't include them.
Add a remote and control your amp from the driver's seat.
For multi-amp systems, you'll need a separate fuse holder.
Helps protect your car's charging system and improves power handling. Required power and ground wires not included with cap.
The right tools will make the installation easier.
Have your new amplifier put in by a qualified professional in your area.
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