Name: Sound Ordnance™ M75-4
Brand: Sound Ordnance
SKU: 777M754
Rating: 4.5 (199 reviews)

Overview

by Crutchfield's

Give your music some firepower

Your vehicle's interior is like an audio battlefield with your music fighting to get heard over the noises of the wind and road. Sound Ordnance's M75-4 4-channel amplifier can provide 75 watts RMS to each of your front and rear speakers — enough power to overcome all the sonic enemies of clean loud music.

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Give your music some firepower

Versatility

You can bridge the M75-4 for 2-channel operation to run a pair of subs with 160 watts RMS each, or send 160 watts to a sub while the front channels run your full-range speakers. Adjustable high-pass filters make 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 filters and adjustable bass boosts allow you to control the bass tone at will.

Rugged and compact

This amp's tiny size lets you fit it almost anywhere in a vehicle. Its tough construction, rugged looks, and 3-year warranty ensure you will enjoy the full power of your music for the long haul. Even better, you can add this Sound Ordnance amplifier to your arsenal at a great price.

Installation note: This amplifier actually has two internal 30-amp fuses that are not user-serviceable without voiding the warranty. When using the M754 in a multi-amp system, we strongly recommend installing an in-line 60-amp fuse between the distribution block and the amplifier.

Sound Ordnance M75-4 75W x 4 Car Amplifier

The ultimate combo: small size, big power, and serious sonic control.

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Product highlights:

4-channel car amplifier
75 watts RMS x 4 at 4 ohms (110 watts RMS x 4 at 2 ohms)
160 watts RMS x 2 bridged at 4 ohms (4-ohm stable bridged)
Class D amp technology
variable high- and low-pass filters (50-750 Hz, 12 dB/octave)
variable bass boost (0-12 dB at 45 Hz)
preamp inputs
cooling fan
8-gauge power and ground leads and a 60-amp fuse recommended — wiring and hardware not included with amplifier
no user-serviceable onboard fuses — when installing multiple amps in a system, an additional 60-amp in-line fuse between the distribution block and the amplifier is recommended
7-1/2"W (8-1/4" with wiring) x 2-1/16"H x 4-3/4"D
warranty: 3 years
Our 60-day money-back guarantee
MFR # M75-4

What's in the box:

Sound Ordnance™ M75-4 owner's manual

4-Channel amplifier
3mm Allen wrench
Four 3/8" Self-tapping screws
4 Split lock washers
4 Flat washers
Owner's Manual

Scratch & Dent items may be missing non-essential accessories. In some cases the manufacturer's accessories have been replaced with generic equivalents.

See the difference between "Open Box" and "Scratch & Dent" Outlet items

Reviews

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Sound Ordnance™ M75-4 reviews

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199 reviews

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Details

Researched by Crutchfield's Mark G.

Features & specs

Performance
RMS Power Output (Watts x Channels)	75 x 4
Peak Power Output (Watts x Channels)	220 x 2
Power at 2 Ohms (Watts x Channels)	110 x 4
Bridged Power (Watts x Channels)	160 x 2
Minimum Impedance Bridged	4
Minimum Impedance Unbridged	2
Minimum Impedance	2
Best Frequency Response	20-20k Hz
THD at Rated RMS Power	1%
Signal to Noise Ratio	100 dB
Input Voltage	13.4v
Features
Amplifier Class	D
Low-Pass Crossover Frequency	50-750 Hz
Low-Pass Slope (dB/octave)	12 dB/oct
High-Pass Crossover Frequency	50-750 Hz
High-Pass Slope (dB/octave)	12 dB/oct
Bass Boost	0-12 dB
Bass Boost Frequency	45 Hz
Fan Cooled	Yes
Fuse Rating	60
Speaker Level Inputs	No
Preamp Outputs	No
Width (inches)	8-1/4
Height (inches)	2-1/16
Depth (inches)	4-3/4
Parts Warranty	3 Years
Labor Warranty	3 Years

The Sound Ordnance™ M75-4 replaces these items:

Product Research

Features
Connections

Features

Power Ratings: The Sound Ordnance M75-4 is a 4-channel Class D amplifier with an RMS power rating of 75 watts per channel into 4 ohms, and 110 watts per channel into 2 ohms. The amp can also be bridged into a 4-ohm load for a power rating of 160 watts (x 2). Power ratings are measured with an input power of 13.4 volts.

Crossovers: The M75-4 is equipped with independent crossovers for the front (channels 1 and 2) and rear (channels 3 and 4) channels. Each can be set to high-pass, low-pass, or full range. The crossover points are continuously variable from 50 to 750 Hz. The crossover slopes are 12dB per octave.

Bass Boost: The front and rear channels also have independent Bass EQ settings. The bass boost is continuously variable from 0 to +12 dB and is centered at 45 Hz.

LED Indicators: There are 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.

Fan Cooled: A thermally-activated fan on the bottom of the amp helps cool the internal components.

Connections

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 3mm Allen wrench is required to tighten/loosen the terminals (included).

Speaker Connections: The speaker terminal can be removed from the amp, which makes connecting the speaker wires easier. The terminal is mounted to the chassis of the amp with two screws. Bare speaker wire, up to 12-gauge, is held in place by screw-clamps on the terminal. A flat blade screwdriver (not supplied) is required to tighten/loosen the screw-clamps.

Signal Inputs: The amplifier has two pair of stereo RCA inputs, one for the front channels and one 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 (item number 142RMM, sold separately). Front-to-back fader capability is lost when using Y-adapters.

Fuses: The M75-4 is protected by two internal 30-amp ATM fuses, accessed by removing the bottom plate. However, removing the bottom plate voids the warranty, so the fuses are not user replaceable within the warranty period.

The Sound Ordnance™ M75-4 replaces these items

Pioneer GM-A6704

4-channel car amplifier — 60 watts RMS x 4

58 reviews

190 watts RMS x 2 bridged
switchable and variable high- and low-pass filters
preamp and speaker-level inputs

Pioneer GM-A4704

4-channel car amplifier — 40 watts RMS x 4

35 reviews

130 watts RMS x 2 bridged
switchable and variable high- and low-pass filters
preamp and speaker-level inputs

Sound Ordnance™ M-4050

4-channel car amplifier — 50 watts RMS x 4

113 reviews

180 watts RMS x 2 at 4 ohms bridged
variable high- and low-pass filters
preamp inputs and outputs

Jensen DUBa4100

4-channel car amplifier — 70 watts RMS x 4

49 reviews

170 watts RMS x 2 bridged at 4 ohms (4-ohm stable in bridged mode)
Class AB amp technology
preamp inputs and outputs

JVC KS-AX3204

DRVN Series 4-channel car amplifier — 60 watts RMS x 4

3 reviews

150 watts RMS x 2 bridged at 4 ohms
preamp and speaker-level inputs
switchable high- and low-pass filters

Sound Ordnance™ M-4075

4-channel car amplifier — 75 watts RMS x 4

80 reviews

240 watts RMS x 2 at 4 ohms bridged
variable high- and low-pass filters
preamp inputs and outputs

Accessories

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Q&A

24 questions already asked

I'm using this amp with a Boss BE7ACP-FT. Can I use the RCA subwoofer output on the receiver for the rear channel RCA input on the amp if using the rear channels of the amp as a bridged output for my subwoofer? Instructions are a bit vague

[ STANLEY R Feb 21, 2023 ]

1 answer

You can use the your subwoofer output on your rear channel instead, you would just have to be mindful of the crossover settings built into the Boss radio. It does have dedicated subwoofer controls so depending on how you have your outputs configured running to your amplifier you can still run everything but your EQ settings may be limited. If you wanted to discuss it in deeper detail you are more than welcome to give us a call at 800.324.9695 and our experts can dive a little deeper and make sure everything works the way you want!

[ ARIELLE H Feb 21, 2023 ] Staff

Can I add two tweeters in parallel with ch1 and ch2 speakers? All 4 ohm speakers

[ DANIEL Oct 23, 2021 ]

3 answers

No. If your connecting separate tweeters you would need a crossover to ensure your sending the correct frequencies to each speaker. Otherwise, you will blow the tweeters.

[ STEVEN Oct 28, 2021 ]

Yes, but will gain nothing & loose left/right.

[ CODY Oct 28, 2021 ]

Wire both in series per each channel.

[ CODY Oct 28, 2021 ]

Has anyone dyno tested this amp to see the actual output? seems to be a VERY small package for 75W x 4 output, even a JL Audio 280/M4 isn't that much wattage for about the same size...

[ TODD May 24, 2021 ]

2 answers

We have not bench tested the model to confirm the RMS watts being output by it and they are not one of the brands that include a certificate of performance either.

[ JASON Jun 22, 2021 ] Staff

This little baby packs a punch. The only down side of this unit is fuse location and how hot she runs. other than that I can confirm the numbers. Bridged Power:160 x 2 (Watts x Channel) Peak Power Output:220 x 2 (Watts x Channel) Power at 2 Ohms:110 x 4 (Watts x Channel) For the price - it is totally worth it. I was tight on space in my 97 TJ, and this did the job. Juiced my soundbar with this baby and have little rock fos kicker in the tail. Makes for a nice drive, doors off tops down.. ride or die.

[ Jon Jun 22, 2021 ]

newb question. can i bridge back 2 to run a small truck box?

[ Sam Oct 16, 2020 ]

3 answers

What do you mean can you Bridge back2!???. Sound Ordnance M75-4. Is a 4-channel car amplifier 75 watts RMS x 4 at 4 ohms (110 watts RMS x 4 at 2 ohms) 160 watts RMS x 2 bridged at 4 ohms (4-ohm stable bridged) Geo*

[ GEORGE Oct 28, 2020 ]

If I understand the question, yes, you could run - A Front L speaker and a Front R speaker (that's 2 channels) - Bridge the other 2 channels to run a single subwoofer up to ~160 Watts RMS, at 4 ohms.

[ SAM Oct 27, 2020 ]

To my knowledge I think this amp is two ohm stable. It would depend on how you have the speakers/subwoofers wired up. I would refer to owner's manual on the website for more information.

[ PRESTON Oct 27, 2020 ]

will this amp work with Memphis audio prx50c and kicker 46csc54?

[ GALEN Aug 12, 2020 ]

1 answer

Thanks for your question. For information on selecting the best amp 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.

[ KRISTINA Aug 25, 2020 ] Staff

Has anyone determined the recommended voltage output to properly set the gain levels?

[ DAT May 19, 2020 ]

1 answer

If you purchased the product from Crutchfield, feel free to contact our Tech Support team. Our toll-free Tech Support number is printed on your invoice, and is also available under the "My Orders" tab in the "My Account" section of our website. If you did not purchase the unit from Crutchfield, then you may want to contact the manufacturer.

[ KRISTINA Jun 03, 2020 ] Staff

I replaced my factory radio by a Pioneer AVH-500EX and I also replaced my original speakers by (4) Kickers 46CSC654, 4ohm, 100Watt each, but the quality of the sound is not that good, at high volume I can feel a considerable distortion, I believe is because the radio doesn't have enough power per channel for the Kickers. Can somebody let me know if this amplifier or any other one could improve the sound quality? Thanks Rudy

[ Rodolfo Apr 19, 2020 ]

1 answer

Rudy, There are quite a few variables that could be causing distortion in your kickers at high volume. Maybe they are getting a little ragged in the low end when cranked up as they are only 6.5's good to about 40 hz. It looks like your head unit provides 50 watts which is pretty respectable. I'm not sure if feeding them 25 more watts per channel would necessarily solve your issue. I can tell you that this is a great little amp. I have it powering some Infinity Reference REF-9630cx 6x9 components up front that can take about 125 watts RMS and the same series of 6.5 coax in the back. It makes them pound and the sound quality and imaging is really good. It has no problem driving these speakers and I believe they would sound pretty anemic without the amp. That being said, I believe these drivers are fair bit of a step up from the kickers you mentioned. Maybe you could try putting in a small subwoofer setup and relieve your 6.5's from the bass duty. This may greatly increase your sound quality. The Crutchfield agents are pretty knowledgeable and may be able to steer you in the right directions. I hope this helps. Good luck. Andrew

[ Andrew Apr 19, 2020 ]

How do you wire this with Speedwire?

[ BENJAMIN Apr 09, 2020 ]

2 answers

I don't think you can. I used #8 wire for power, RCA jacks and #14 gauge for speakers

[ Ken Apr 10, 2020 ]

Hi Ben, unfortunately I've never used SpeedWire, but assuming that it has the positive and negative wires, it should be no different as far as your speakers are concerned. Just make sure your + goes to + and - to - and should be good!

[ Josh Apr 09, 2020 ]

I am confused when hooking up. What do I plug into the remote?

[ Hood Sep 11, 2018 ]

2 answers

if you are talking about the remote wire,,then you have to look at the rear of your head unit,,there is a purplish wire that should have a little tag that says remote wire,,connect the wire to the back of head unit,,then run the remote wire to the amp,,,done

[ PARASCHOS P Sep 14, 2018 ]

That's for the switched turn on lead from the radio itself. That way the amp is only powered on when the radio is on. On aftermarket stereos it's usually a blue wire in the wiring harness of the stereo itself. The 12v should come directly from the battery and the ground should be attached to the body of the vehicle close to the amplifier.

[ MICHAL Sep 14, 2018 ]

What is the screw between power and input for?

[ Hood Sep 10, 2018 ]

2 answers

Check your wiring. The remote or input from the headunit should be in between the power and ground cable if that's you're asking.

[ Steven Sep 11, 2018 ]

That is the remote control connector. It will power on the amp when it receives +12v current. There should be an output on your radio for it.

[ BENJAMIN Sep 10, 2018 ]

Does the fader affect the RCA outputs?

[ KEVIN Jan 30, 2018 ]

1 answer

If you're referring to the fader controls on your head unit, then that would affect the RCA outputs on your head unit. For more details or to discuss further, please feel free to contact an Advisor directly by phone (888.955.6000) or online chat. Thanks!

[ DAVID Feb 06, 2018 ] Staff

How many volts does the remote turn on wire need to turn on the Amp? Would 11 volts be enough to power up?

[ Gerard Jan 27, 2018 ]

4 answers

I don't even think it needs that much. A 12v power source from anywhere will work. I think it's 100 miliamps or something like that. The power cable that comes into it is actually what powers up the amp, the remote turn on just tells it to turn on.

[ Austin Feb 04, 2018 ]

That should be plenty. It technically turns on with a 12v input, but you can get away with 10-14

[ Jacob Feb 03, 2018 ]

Sorry I don't know the answer but I do like the amp

[ PATRICK Feb 02, 2018 ]

I have no problem with amp turning on at 11 vdc

[ DAVID Feb 01, 2018 ]

Can this run in a vertical position or will that cause fan damage?

[ PHILLIP R Nov 17, 2017 ]

2 answers

Should be ok to run in any positon, as long as there is good air flow.

[ Ezekiel Nov 20, 2017 ]

I run mine vertically with no issues.

[ Ryan Nov 20, 2017 ]

Can I run this amp at 4 ohms for the front and 2 ohms for the rear or will it see the all 4 channels at 2 ohms or will I get funny sound out of it?

[ Krooked Oct 19, 2017 ]

1 answer

Yes, the Sound Ordnance M75-4 amp will support one pair of 2-ohm speakers and one pair of 4-ohm speakers connected to the front and rear channels. For more specific details about that, please feel free to contact an Advisor directly by phone (888.955.6000) or online chat. Thanks! :)

[ DAVID Oct 24, 2017 ] Staff

Can this be bridged to a second M-75 ?

[ Chris Jun 08, 2017 ]

1 answer

The Sound Ordnance M-75 does not have any preamp outputs to "daisy chain" two of them together. If you would like to discuss further please feel free to contact an Advisor directly by phone (888.955.6000) or online chat. Thanks!

[ DAVID Jun 13, 2017 ] Staff

will this fit behind the dash or console of a "06 4Runner, or do I have to mount it under the seat?

[ DAN Jun 01, 2017 ]

1 answer

For additional 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.

[ KENNETH Jun 02, 2017 ] Staff

What are the dimensions of this amplifier?

[ TRENT D Feb 28, 2017 ]

2 answers

It is small, 4.25w by 2h by 7.25 deep inches

[ GREG Mar 01, 2017 ]

4-3/4" X7"X1" with 7" just make sure you leave room for your plug-ins on one end. Great little amp. Very happy with it.

[ IRA Mar 01, 2017 ]

The specs show SnR of 100dB. Since this amp is not 2006 compliant, how is the SnR measured?

[ Eric Jan 25, 2017 ]

1 answer

Though we don't have anything "concrete" regarding how the S/N ratio is measured on the Sound Ordnance M75-4, our product researchers informed us that it was likely obtained from the rated power (75 watts RMS @ 4-ohm) at 1kHz; since that's how most non-CEA 2006 compliant amplifier's measure the S/N ratio. If you would like to discuss further, feel free to contact an Advisor directly by phone (1-800-324-9695) or online chat.

[ DAVID Feb 07, 2017 ] Staff

Will this work with a pair of Alpine SPR-68 4 ohm along with 2 Subs Kicker 40CWRT672? http://www.crutchfield.com/p_500SPR68/Alpine-SPR-68.html http://www.crutchfield.com/p_2064CRT672/Kicker-40CWRT672.html

[ ziocomposite May 15, 2016 ]

1 answer

It should.

[ IRA Mar 01, 2017 ]

Can this run a pair of Alpines R68 4 ohm along with 2 Subwoofers Kickers 40Cwrt672 2 ohm? http://www.crutchfield.com/p_500SPR68/Alpine-SPR-68.html?search=alpine_spr_68&skipvs=T http://www.crutchfield.com/p_2064CRT672/Kicker-40CWRT672.html

[ ziocomposite May 15, 2016 ]

2 answers

Yes

[ DAVID Feb 01, 2018 ]

Absolutely. You could power the pair of Alpine 6x8" with 2 of the channels and bridge the other two to power the subwoofer. You'll just need to wire the dual 2 Ohm coils in series to present a final 4 Ohm load to the bridged channel. I hope that helps! My Bio: http://www.crutchfield.com/Support/Bio.aspx?bio=5

[ Ryan May 18, 2016 ] Staff

Will this amp work with my factory 1992 Honda Accord stereo and four (2 front 2 rear) new Jensen DUBS265 2-way speakers (2-70 watts RMS)? Enough power? Overkill?

[ GILBERT Mar 05, 2016 ]

1 answer

You will want to contact an Advisor by phone (1-800-324-9695) or online chat to discuss compatibility with your factory system. They will be able to pull up your vehicle and see if this will integrate. If it does not, then they will also be able to discuss other options with you.

[ KENNETH Mar 05, 2016 ] Staff

I have a 2015 Nissan Versa S. I'm looking to power 4, morel 80watt 6.5 coax speakers off this. In addition I want to purchase a JBL GT-BassPro12 powered sub. Can I keep my factory head unit and get the sub this amp and the speakers and be all set? Any other suggestions? I'm new to the car audio world.

[ Donavan Mar 03, 2016 ]

3 answers

this is a 4 channel amp it will power your main speakers but not the sub

[ ROBERT Mar 04, 2016 ]

For me, this amp comfortably powers 4 speakers of similar caliber. It is crisp and clean. However it will not also power a sub at the same time. You can power 2 speakers and a sub, but not 4 + sub. In terms of the existing head unit, it has to have the ability to accommodate an external amp. My 2000 Jeep could not so I bought a new head unit. Running all of the wires through mounding, etc was time consuming and drilling a hole through my firewall to run the power to the battery was intimidating, but I did it all in about a day and am very pleased.

[ Robert Mar 04, 2016 ]

The Sound Ordnance amp will give your speakers the power they need even with your factory head. However, you'll need a separate amp to power the JBL sub.

[ Joshua Mar 03, 2016 ]

i purchased a pioneer mono block amp from you guys along with this 4 channel sound ord. amp...not sure on how to power both amps...the mono amp uses 4 awg and the sound ord uses 8...can the sound ord accept a 4awg? most of the dual amp kits are 0/1 with dist block that output 4awg not 8awg...any advice?

[ mark t Feb 24, 2016 ]

1 answer

If you purchased the product from Crutchfield, feel free to contact our Tech Support team. They can walk you through the settings on the product and see if there may be a fix. Our toll-free Tech Support number is printed on your invoice, and is also available under the "My Orders" tab in the "My Account" section of our website.

[ KENNETH Feb 24, 2016 ] Staff

will this fit under the seat of a 2015 wrangler jk?

[ DAVID Jan 13, 2016 ]

8 answers

I'd have to say yes. Geek Squad was able to install this bad boy in a compartment in the lower part of my dashboard in a '07 Malibu. That leads me to believe the SO M75-4 fits just about anywhere.

[ Joshua Jan 15, 2016 ]

yes it will

[ ROBERT Jan 14, 2016 ]

Dimensions are 8 1/4" X 4 3/4" X 2 1/16" so this is a small package. I don't know how much room is under the seat of a JK Wrangler but I would say you have plenty of room. I mounted it on the waterfall space between the seats of my 1972 Corvette. Works very well and I love the features. I will tell you, get the speaker wires connected prior to mounting the amp down as you can not access the screws to the connector with it mounted. Really the only down side to the whole package!

[ Kim Jan 13, 2016 ]

Absolutely!! It is a very small amp, but has plenty of power. I am very pleased with it, and would recommend it to anyone. Matt T

[ MARILYN Jan 13, 2016 ]

It fit under my driver seat in my 2013 wrangler jk fine, it's a small amp and works great!

[ Julie Jan 13, 2016 ]

Yes

[ kenneth Jan 13, 2016 ]

Im not really sure. It is pretty small. But, it does require room for ventilation. This thing is built well and works great.

[ IRA Jan 13, 2016 ]

I Believe it should. You will have to be careful with your wiring. My only complaint with the amp is that. With the size of the amp and having the wires enter on both ends increases the length of it by 3 - 4 inches

[ Joe Jan 13, 2016 ]

SHOW MORESHOW LESS