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Sound Ordnance M-4050

4-channel car amplifier — 50 watts RMS x 4

105 Reviews | 14 questions - 37 answers

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Our take on the Sound Ordnance™ M-4050

Win the battle for great sound in your ride. Sound Ordnance amplifiers feature tough construction, rugged looks, and a 3-year warranty, so you can enjoy the full power of your music for the long haul. Even better, you can add Sound Ordnance to your arsenal at a surprisingly affordable price.

Win the battle for great sound in your ride. Sound Ordnance amplifiers feature tough construction, rugged looks, and a 3-year warranty, so you can enjoy the full power of your music for the long haul. Even better, you can add Sound Ordnance to your arsenal at a surprisingly affordable price.

The Sound Ordnance M-4050 4-channel amplifier deploys 50 watts RMS to each channel, giving your music plenty of firepower. You can also bridge the amp to 2-channel mode to mobilize a pair of subs with 180 watts RMS each, or send 180 watts to a sub while the front channels run your full-range speakers. An adjustable high-pass filter makes sure your full-range speakers operate within their optimum range and give you the best tone possible. If you're driving a sub, the low-pass filter and selectable bass boost allow you to control your bass barrage at will.

The M-4050 amplifier uses sophisticated power supply and output technologies to ensure clean amplification from the inputs all the way to your speakers. Special circuits protect the amp from overheating and short circuits, and a turn-on delay virtually eliminates that annoying thump when you turn your system on.

Works extremely well, easy to mount and use. Plugs work very well. I only have at half gain and the quality and volume is great.

Chase, College Station, TX

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What's in the Box:

  • 4-Channel amplifier with two 20A ATC blade fuses inserted
  • Spare 20A ATC blade fuse
  • 4 Self-tapping screws (5/8" length)
  • 4 Split lock washers
  • 4 Flat washers
  • Owner's Manual

Product Highlights:

  • 4-channel car amplifier
  • 50 watts RMS x 4 at 4 ohms (90 watts RMS x 4 at 2 ohms)
  • 180 watts RMS x 2 bridged at 4 ohms (4-ohm stable bridged)
  • variable high-pass filter (120-3,000 Hz, 12 dB/octave)
  • variable low-pass filter (50-250 Hz, 12 dB/octave)
  • selectable bass boost (0, 6, and 12 dB at 45 Hz)
  • PWM (pulse width modulation) power supply with MOSFET output
  • preamp inputs and outputs
  • fuse rating: 20A x 2
  • 8-gauge power and ground leads recommended — wiring and hardware not included with amplifier
  • 14-1/8"W x 2-1/8"H x 9-13/16"D
  • warranty: 3 years
  • Our 60-day money-back guarantee

Sound Ordnance™ M-4050 Reviews

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(105 Reviews)
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Product Research



Power Ratings: The Sound Ordnance M-4050 is a 4-channel Class AB amplifier with an RMS power rating of 50 watts per channel into 4 ohms, and 90 watts per channel into 2 ohms. The amp can also be bridged into a 4-ohm load for a power rating of 180 watts (x 2). Power ratings are measured with an input power of 14.4 volts.

Crossovers: The M-4050 is equipped with both high-pass and low-pass crossovers. The front channels (channels 1 and 2) and the rear channels (channels 3 and 4) have separate crossovers. You can set the low-pass cutoff frequency between 50Hz and 250Hz, and the high-pass cutoff frequency between 80Hz and 2 kHz. Separate switches let you select low-pass, high-pass, or full range operation for the rear channels, and high-pass or full range for the front channels. The crossovers have a 12dB per octave slope.

Bass Boost: The amplifier has a bass boost switch, labeled Super Bass, to give small subwoofers more volume in the low frequencies. You can select the amount of boost with the 3-way switch: 0dB, 6dB, or 12dB. The Super Bass feature is available for the rear channels only.

LED Indicators: The M-4050 features two LED indicators: a green LED that illuminates when the amp is powered on, and a red LED that illuminates when the amplifier is in protect mode due to overheating or a short circuit in the speaker wire.


Removable End Caps: The end caps on the M-4050 are removable with a 3mm Allen wrench (not supplied) to make it easier to attach the power and speaker wires.

Power Connections: The power and ground connections are set screw terminals that will accommodate up to 8-gauge wire. (An 8-gauge amplifier wiring kit is recommended.) The remote turn-on terminal is a set screw terminal that will also accept up to 8-gauge wire. A Phillips-head screwdriver (not supplied) is required to tighten/loosen the terminals.

Speaker Connections: The speaker connections are set screw terminals that will accommodate up to 8-gauge wire. A Phillips-head screwdriver (not supplied) is required to tighten/loosen the terminals.

RCA Inputs and Outputs: The amplifier features two pairs of stereo RCA inputs for connecting your head unit--one pair for the front channels and one pair for the rear channels. If your head unit only has one pair of preamp outputs, you can feed all four amplifier channels by connecting optional Y-adapters. (You will lose front-to-back fader capability if you connect the amplifier using Y-adapters.) There is also a pair of stereo RCA outputs for feeding the preamp signal to another amplifier, if needed.

Fuses: The M-4050 features two 20-amp ATC blade fuses.

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 verify what’s in the box, 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.

Staff Reviews

Product reviews from the Crutchfield Labs

Make your music sound lively and vital with a Sound Ordnance amplifier. Watch this Crutchfield video to see what these rugged, value-packed amplifiers have to offer.

What are the Labs?
Q & A

Customer Q&A

Crutchfield asked  
Why did you buy this?

Value for quality [ Chase  May 15, 2017 ]
I wanted a 4 channel amp to drive my four 6.5 door speakers and the new B-12 sub that I ordered. I especially like the preamp out that would give me expansion options for the future. I really appreciate the Crutchfield customer service and quality of products that they sell. [ Jonathan  May 12, 2017 ]
The customer service person recommended it, and it had very good feedback, and the price was right. [ TOM P  May 05, 2017 ]
Enough power for the truck cabin & inexpensive. [ Norman  Apr 24, 2017 ]
Consumer ratings [ Andrew  Apr 23, 2017 ]
high quality. good price [ donna  Apr 15, 2017 ]
Affordable and reliable [ Ian  Apr 01, 2017 ]
it was cheap [ lucas  Mar 27, 2017 ]
Good reviews and good price. I also like the looks. [ Thomas  Mar 22, 2017 ]
price and features of being able to power a set of rear speakers and bridge the second channel to power a small sub. [ David  Feb 21, 2017 ]
Reviews [ Keith  Feb 18, 2017 ]
Recommend by Norm at Crutchfield and again 3 year warranty on this amp hard to beat that. [ L  Dec 31, 2016 ]
Meets my specifications [ Matt  Dec 18, 2016 ]
I installed this amp in the rear compartment of an 84 Ford ambulance that I converted to a utility vehicle, it powers 2 pair of Kicker CSS65 cab and intermediate speakers. The sound out of it is incredible! It is also a great value! [ DANIEL  Oct 23, 2016 ]
Great price and positive reviews [ Joseph  Sep 28, 2016 ]
Recommended [ Angela  Sep 03, 2016 ]
I needed a 4 channel amp that just put out a little more power to feed my hungry speakers. I like the layout and the screw terminals better than the giant terminal of the smaller more compact sound ordinance. [ Alexander  Aug 29, 2016 ]
price, the company values . [ Michael  Jul 31, 2016 ]
Great experience with products and great prices [ Heather  Jun 01, 2016 ]
looked like a good value. many good reviews [ Boyce  Apr 25, 2016 ]
It's hides wires well [ Michael  Mar 30, 2016 ]
Had this amp before and it is perfect combination of bang for the buck -- efficient and strong amp that can take a beating at a very reasonable price!! [ Bradley  Mar 21, 2016 ]
Bought two of the Sound Ordnance component sets and wanted a suitable 4 channelx50 watt amp. This fit the bill pefectly and great price! [ Michael  Mar 13, 2016 ]
Reviews looked good, building a budget system, and this fits my budget. [ BARBARA A  Feb 23, 2016 ]
After talking to a CF rep, they recommended it. Your employees are always helpful and polite....too bad more companies cant have employees like that. Good job! [ Steve  Feb 08, 2016 ]
Good price good features. [ STEVEN  Jan 20, 2016 ]
Previous purchase, like it, so purchased second one. [ MELVIN A  Jan 19, 2016 ]
To replace a similar but old (size & channel format) amplifier that lost a channel. [ John  Dec 31, 2015 ]
price [ JOHN  Dec 13, 2015 ]
Reviews [ Jay  Dec 10, 2015 ]
Great power, minimal THD at rated power, and a S/N ratio of over 90db for $100 ? Are you kidding me? Its a no-brainer... [ mick  Dec 09, 2015 ]

14 questions already asked

While some hyper sensitive enthusiasts will argue the point; you will be fine with the speakers you have. Mine bounces around under the seat of my 4x4 and it has performed great for 2 years now. Sounds great. [ stanton  Mar 14, 2017 ]
I'm sure it would do fine. I would ask the techs at Crutchfield. Their customer service is amazing. I've bought 3 sound ordinance subs in 2 years and love them all. [ MICHAEL  Mar 14, 2017 ]
It will will work fine, this amp has plenty of power. [ RAYMOND  Mar 13, 2017 ]
You can get a distribution block. Normally they are 4 gauge in and 8 gauge out 2 or 4 way. [ MICHAEL L  Feb 16, 2017 ]
He cleaneat way would be to run your 4 amp to a fuse box as close to the amp. Then run your 8 amp from there to the amp. That helps if you want to run anothet amp later. If you dont want to do that, you could simply remove some of the wiring from the 4 gauge to get it to where it would fit. [ David  Feb 16, 2017 ]
SnR can be measured on a amps individual inputs and outputs using a mathematic formula. [ Edric  Jan 26, 2017 ]
All you need is a regular amp wiring kit if you are going to run it 4 channel, I ran it two channel, with two 12 subs, only lasted for about 4 -5 months, would not suggest, spend a little more money and get a lot better. [ TIM  May 29, 2016 ]
The filters aren't fixed, so you can set up for full range. I don't think you can set filters on less than 2 inputs at a time. Power from the car battery is adequate for this amp. Hope that answers your question! [ Maurice  May 28, 2016 ]
FWIW - I have my amp running to a pair of subs only. Personally I like to go large (4ga from batt,) but I think you'd be safe with 8 - provided you are only installing one amp. As for speaker cable, 12ga to my subs and 10 to the rest. This amp has performed well so far (2 yrs??). [ Maurice  Apr 21, 2016 ]
Like many amplifiers, the Sound Ordnance models are rated at a 14.4 volt power input. Because most electrical systems will average closer to 12-13 volts, the output per channel will be slightly lower than rated. I hope that helps! My Bio: [ Ryan  Apr 15, 2016 ]  Staff
Sure you can but the built in ones work well! So well, someone stole my son's car for it! Good amp and it will work in most situations. [ GERALD  Sep 29, 2015 ]
Yes. You can use a passive crossover with any amp. Just be sure it will handle the rated power (watts) output of the amp. Depending on the radio you have, and your set up, you might be able to use built in crossovers in the radio. Hope this helps. [ 181jonathan  Sep 29, 2015 ]
I forwarded your question to an Advisor and they responded with the following: The RCA outputs on this stereo are used for sending a signal to another amplifier. We call this daisy chaining the amps. If you would like to discuss further you can contact an Advisor directly by phone (1-800-324-9695) or online chat. [ Krissy  May 27, 2015 ]  Staff
For details on fit or installation please contact an Advisor by phone (1-800-324-9695) or online chat. They will be able to pull up your vehicle and give you the details on if this will fit and what you will need for an installation in your vehicle. [ Krissy  Apr 13, 2015 ]  Staff
Its affiliated with Crutchfield, so through them would be the answer. [ PAUL T  Nov 12, 2014 ]
We have not received any answers from other customers on your question. I would recommend reaching out to an Advisor by phone (1-800-324-9695) or online chat. They should be able to help answer your question. [ Krissy  Jul 09, 2014 ]  Staff
Sorry it took so long That's a 4 channel amp . You hook up your 6x9 rear speakers , door speakers that's about all if you want to hook up 2 , 10"subs get the s/o 1350 [ JESUS E  Apr 12, 2014 ]
I put one have a truck and don't have MUCH ROOM BUT THIS AMP HAS PLENTY OF POWER FOR MORE [ JOHN  Apr 09, 2014 ]
2 - infinity 10's this amp isn't what u think I don't like it. [ ANTHONY R  Apr 07, 2014 ]
I didn't throw a single sub at this bad boy. I did, however; put some powerful full-range speakers in my car and attached them to that amp. They are LOUD and crystal clear. I know for a fact that this amp could power a few decent subs or one or two powerful ones without a hiccup. [ WOODROW CULPEPP  Apr 07, 2014 ]
None. I am driving 2 6x9's with it, and using an mp3 player instead of a head unit. [ KURTIS  Apr 07, 2014 ]
One 10 inch [ THEODORE  Apr 07, 2014 ]
Just one bazooka tube in a boat. Had to turn this down to minimal output cause it was too much juice. I'm. Not a full blown stereo dude though, just a regular guy. [ CORBYN  Apr 07, 2014 ]
Zero. I used it to power 2x 100w mids by Polk. [ ERIC  Apr 07, 2014 ]
One sub. I think it can take two. [ RONALD W.  Apr 07, 2014 ]
Just one bazooka tube in a boat. Had to turn this down to minimal output cause it was too much juice. I'm. Not a full blown stereo dude though, just a regular guy. [ CORBYN  Apr 07, 2014 ]
Thanks for your question. For information on selecting the best amp for your speakers I would recommend reaching out to an Advisor by phone (1-800-324-9695) or online chat. They will be able to help determine the differences between the amp models and help you make the best choice for your system. [ Krissy  Jan 26, 2014 ]  Staff
Good evening Aaron, i wish I could help but returned the unit due to the size. [ JUAN  Jan 06, 2014 ]
I have had no issues with it and it is very easy to adjust and gives good power output. [ LANCE C  Jan 05, 2014 ]
it's ok but you get what you pay for. [ ANTHONY R  Jan 05, 2014 ]
Aaron I purchased this for my daughter's car and it is awesome! She and her friends get rocking and I can hear her coming home a block away. (not good for neighborly accord) The quality is way above the other units I looked at. The only negative , and it's really not a huge deal, but the attaching port for the keyed wire to turn on the unit is for a 10 ga. wire and the wire that is sent to attach there is probably a 16 ga. so you have to fold and solder the end to get it to be captured by the set screw. Other than that its been great. Good value for the money. Dave J [ DAVID R  Jan 05, 2014 ]
I just put this in my sons car and was able to crank it up almost all the way up with no distortion. I will be putting this in my hot rod as well! Money well spent! [ GERALD  Jan 05, 2014 ]
It's a quality amp for a significantly cheaper price than the name brands out there. I bought it with kicker 3ways in the back and it brought the life out of those and was hitting wayyyy lower notes than I could get with the kicker 30w amp I had. Definitely would suggest buying it. [ DAWSON  Jan 05, 2014 ]
I was a little skeptic about this amp when i was searching for one for my speakers, but for the price and everything, i figured i'd give it a try. I was very pleased first of all with the service from crutchfield and the easy of installation. Everything on the amp is marked very well and its very self explanitory. The quality of the amp is great too! The output you get is just so clean and for the price, its pretty much unbeatable. You can get the same from alpine or kenwood or any others for that matter, for double the price though. Definately would recommend it, especially if you're trying to stay in a budget. [ MALINDA J  Jan 04, 2014 ]
This was my first so I'm not sure how it compares with others. But i can tell you that it is really good And has held up well. No problems [ THOMAS  Jan 04, 2014 ]
I really enjoy this amp for the price and design but tuning it can sometimes be a hassle since it's Angled oddly. Overall it's a great product [ OSVALDO  Jan 04, 2014 ]