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Sound Ordnance M75-4

Compact 4-channel car amplifier — 75 watts RMS x 4

Item # 777M754

Your vehicle's interior is like an audio battlefield with your music fighting to get heard over the noises of the...

Find what Fits your car

Your vehicle's interior is like an audio battlefield with your music fighting to get heard over the noises of the...

California customers:
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In stock
$139.99

About the Sound Ordnance M75-4

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.

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.

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.

READ LESS

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:

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

Customer reviews

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Sound Ordnance M75-4 reviews

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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 120RCAY1, 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.

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Customer Q&A

22 questions already asked

Q
newb question. can i bridge back 2 to run a small truck box?
[ Sam  Oct 16, 2020 ]
3 answers
A
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*
[ GeosStar  Oct 28, 2020 ]
A
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.
[ Samuel  Oct 27, 2020 ]
A
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 ]
Q
will this amp work with Memphis audio prx50c and kicker 46csc54?
[ galen  Aug 12, 2020 ]
1 answer
A
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.
[ Krissy  Aug 25, 2020 ]  Staff
Q
Has anyone determined the recommended voltage output to properly set the gain levels?
[ Dat  May 19, 2020 ]
1 answer
A
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.
[ Krissy  Jun 03, 2020 ]  Staff
Q
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
A
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 stewart  Apr 19, 2020 ]
Q
How do you wire this with Speedwire?
[ Ben  Apr 09, 2020 ]
2 answers
A
I don't think you can. I used #8 wire for power, RCA jacks and #14 gauge for speakers
[ Ken  Apr 10, 2020 ]
A
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 ]
Q
I am confused when hooking up. What do I plug into the remote?
[ Herb c  Sep 11, 2018 ]
2 answers
A
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
[ Pete  Sep 14, 2018 ]
A
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 ]
Q
What is the screw between power and input for?
[ Herb c  Sep 10, 2018 ]
2 answers
A
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 ]
A
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 ]
Q
What is the recommended voltage output?
[ benjamin  Apr 01, 2018 ]
1 answer
A
Olathe output?? Hmm. I don't understand. You need a 12 volt battery system to run the amp. It's output is in watts. It's 75 Watts a channel and has 4 channels at 4ohms You can bridge down from there if you want to 2 channels. It's a nice amp for a beginner or basic system. It will give you very good sound at a pretty high volume just not a compatition amp
[ DANA M  Apr 07, 2018 ]
Q
Does the fader affect the RCA outputs?
[ Kevin  Jan 30, 2018 ]
1 answer
A
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!
[ Larry  Feb 06, 2018 ]  Staff
Q
How many volts does the remote turn on wire need to turn on the Amp? Would 11 volts be enough to power up?
[ Gerry  Jan 27, 2018 ]
4 answers
A
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 ]
A
That should be plenty. It technically turns on with a 12v input, but you can get away with 10-14
[ Jacob  Feb 03, 2018 ]
A
Sorry I don't know the answer but I do like the amp
[ PATRICK  Feb 02, 2018 ]
A
I have no problem with amp turning on at 11 vdc
[ DAVID  Feb 01, 2018 ]
Q
Can this run in a vertical position or will that cause fan damage?
[ Randy  Nov 17, 2017 ]
2 answers
A
Should be ok to run in any positon, as long as there is good air flow.
[ ZEKE  Nov 20, 2017 ]
A
I run mine vertically with no issues.
[ Ryan  Nov 20, 2017 ]
Q
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
A
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! :)
[ Larry  Oct 24, 2017 ]  Staff
Q
Can this be bridged to a second M-75 ?
[ Kcmtbr  Jun 08, 2017 ]
1 answer
A
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!
[ Larry  Jun 13, 2017 ]  Staff
Q
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
A
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.
[ Kenny  Jun 02, 2017 ]  Staff
Q
What are the dimensions of this amplifier?
[ Trent  Feb 28, 2017 ]
2 answers
A
It is small, 4.25w by 2h by 7.25 deep inches
[ Greg  Mar 01, 2017 ]
A
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 ]
Q
The specs show SnR of 100dB. Since this amp is not 2006 compliant, how is the SnR measured?
[ Joe  Jan 25, 2017 ]
1 answer
A
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.
[ Larry  Feb 07, 2017 ]  Staff
A
Yes
[ DAVID  Feb 01, 2018 ]
A
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
Q
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
A
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.
[ Kenny  Mar 05, 2016 ]  Staff
Q
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
A
this is a 4 channel amp it will power your main speakers but not the sub
[ ROBERT  Mar 04, 2016 ]
A
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 ]
A
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 ]
Q
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
A
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.
[ Kenny  Feb 24, 2016 ]  Staff
Q
will this fit under the seat of a 2015 wrangler jk?
[ dr  Jan 13, 2016 ]
8 answers
A
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 ]
A
yes it will
[ ROBERT  Jan 14, 2016 ]
A
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 ]
A
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 ]
A
It fit under my driver seat in my 2013 wrangler jk fine, it's a small amp and works great!
[ Julie  Jan 13, 2016 ]
A
Yes
[ kenneth  Jan 13, 2016 ]
A
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 ]
A
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 ]
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