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Skar Audio

Skar Audio SK-M4004D Compact Full-Range Class D 4 Channel Car Amplifier, 400W

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Availability: Only 1 left in stock, order soon!
Fulfilled by SKAR AUDIO
Arrives Saturday, Feb 14
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Size: 400 Watt RMS Class D Four Channel


Features

  • Ultra Compact MOSFET Full-Range 4-Channel Class D Car Amplifier
  • RMS Power @ 2 Ohms: 140 Watts x 4 Channels (14.4v)
  • RMS Power @ 4 Ohms: 100 Watts x 4 Channels (14.4v)
  • Crossover Controls: HPF / Full-Range / LPF | Frequency Response: 10Hz - 40kHz
  • Hi-Level Input Connections: Yes | 8 Gauge Power and Ground Input Terminals

Description

The Skar Audio SK-M4004D is an ultra compact, "mini", Class D full-range, four channel car speaker amplifier. The SK-M4004D was engineered to be compact, but provide the power and reliability expected out of larger amplifiers. Featuring a high speed MOSFET power supply, and an efficient Class D design, this amplifier is powerful, reliable, and extremely versatile. The SK-M4004D makes for a great amplifier in applications where space is limited but power cannot be sacrificed. In addition, this four channel amplifier features high level input connections for those installations that lack an RCA connection. In addition to the high level inputs, this amplifier also utilizes an adapter harness for the speaker outputs allowing for an easier and cleaner installation. Further adding to the feature rich list of this amplifier are its high pass / full-range / and low pass user controls, as well as having 4-Way Protection Circuitry Built-in (Thermal, Voltage, Speaker, DC). Utilizes 8 Gauge Power and Ground Input Terminals. Amplifier's dimensions: 7.9in x 4.6in x 1.7in (L x W x H). Frequency Response: 10Hz - 40kHz.

Item dimensions L x W x H: 7.9 x 4.64 x 1.65 inches


Voltage: 14.4 Volts


Manufacturer: Skar Audio


Maximum Supply Voltage: 14.4 Volts


Minimum Supply Voltage: 14 Volts (DC)


Item dimensions L x W x H: ‎7.9 x 4.64 x 1.65 inches


Voltage: ‎14.4 Volts


Manufacturer: ‎Skar Audio


Maximum Supply Voltage: ‎14.4 Volts


Minimum Supply Voltage: ‎14 Volts (DC)


Mounting Type: ‎Surface Mount


Brand: ‎Skar Audio


Number of Channels: ‎4


Output Power: ‎400 Watts


Material: ‎Mosfet


Global Trade Identification Number: ‎65


UPC: ‎739189979165


Item Weight: ‎3.74 pounds


Product Dimensions: ‎7.9 x 4.64 x 1.65 inches


Item model number: ‎SK-M4004D


Is Discontinued By Manufacturer: ‎No


Warranty: ‎2 year limited warranty


Date First Available: April 25, 2016


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Saturday, Feb 14

Yes, absolutely! You may return this product for a full refund within 30 days of receiving it.

To initiate a return, please visit our Returns Center.

View our full returns policy here.

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Similar Products

Top Amazon Reviews

    • Powerful, Clean, and Compact 🔥
Size: 400 Watt RMS Class D Four Channel
This Skar Audio SK-M4004D amp is a beast in a small package — delivers crisp, distortion-free sound and plenty of power for all four channels. It runs cool, fits anywhere, and really wakes up your speakers. Perfect mix of size, strength, and quality. 💪
Reviewed in the United States on October 14, 2025 by David Houck
    • Great deal for Mini Amp!
Size: 500 Watt RMS Class D Monoblock
Review Image by Dereck W. Dereck W.
Review Image by Dereck W. Dereck W.
Review Image by Dereck W. Dereck W.
Review Image by Dereck W. Dereck W.
I ran this mini 500W amp through my tests including RMS Power output tests using the SMD Amp Dyno. The little Skar amp performed as advertised, no surprises. Skar has an Amp Dyno as well and confirms their ratings with all of their amplifiers. See the attached image of the Amp Dyno results if you're interested in the numbers. You can also see the size comparison to the Sundown SAM-500D, which is not only quite a bit more expensive, but also has the marine coating on the board (whereas the Skar does not). That said, I'd be careful using this Skar SK-M5001D in any environment where getting wet is a possibility. It's better suited for small spaces inside the vehicle. The amp powered the custom 600 watt 12" subwoofer (D2) in the acrylic enclosure with no issues. Sound was deep and dynamic with plenty of output. I also had a technician review the internal components and minus the old design of the driver card with known overheating problems, the amp was given a passing rating. Overall great value for the money. Dereck from Williston Audio Labs ... show more
Reviewed in the United States on February 15, 2020 by Dereck W. Dereck W.
    • I gotta admit this amp is a lot of bang for the buck.
Size: 900 Watt RMS Class D Five Channel
As someone who has been into car audio for several decades I was very skeptical that this amp would perform for this low of a price. I read reviews and watched YouTube vids of amp dynos and this amp is legit. It puts out more power and sound than my alpine amp I replaced with it and for a fraction of the cost. It’s definitely worth the money and it performs very well. I haven’t had any problems with it so far and it hasn’t shut down from heat or anything either. I’m pretty impressed and I think you will be too. I’m definitely recommending it and if you’re on the fence about it, go for it. ... show more
Reviewed in the United States on April 27, 2024 by Nitz5785
    • It's the best you can get at this price.
Size: 400 Watt RMS Class D Four Channel
The amplifier is in itself built well and performs as you can expect a budget friendly amp will. As per sound quality I installed this on my truck and it is quite comparable to the 600$ old kenwood that came out of it. It however does have some things to note that are important at this price point, the warranty is voided as soon as you install this thing, the internal components however good are still basic in nature, the installation process is slightly tedious with the output side clip but is expected, and the amp does get quite warm. Because the amp is basic in nature it lacks (at least in my experience) a line filter so that power from your alternator does not affect sound quality. You can simply buy a noise suppressor for the power feed to solve this issue. I did experience the fan never turning off and this was a problem as it does make an audible noise while on. I after already installing the unit and figuring this out, decided to break down the amp and disconnect the fan altogether. There is a simple clip you undo that is delicate but doable. THIS WILL VOID A WARRANTY. But it did solve my problem and after dynoing my 4 door speakers at full throttle for 20 minutes my amp did not get hot just the warmer side of things. After all the little fan didn't do much. I only did this because my amp is mounted by floating brackets under my passenger seat; if this was in a glove box or the trunk of a car there would be no problem. Other than the the sound quality is clean and powerful, the unit is built well and on the good side of heavy (not feeling cheap), and I can expect it to last. Update* the amplifier died after a few months of running it hard. However if you run it well within its ratings I believe it should hold up well ... show more
Reviewed in the United States on May 22, 2022 by Jerry Westheimer
    • Filter the reviews by amp model
Size: 900 Watt RMS Class D Five Channel
If you’re looking at the SK-M9005D, filter the reviews for five channel amp which sucks. Purchased the 5 channel amp based on high review rating but was fooled. If you filter for only the sk-m9005d, you will see most are experiencing the same thing that is happening to mine. It overheats and shuts off for a few seconds then back on. It repeats this over and over. When it was first installed it seemed to work fine but after two weeks it started and keeps getting worse. Unfortunately I’m past the return window or it would be going back. I usually don’t get fooled by Amazon, but in this case, I feel that I was. This model amp should have its own listing so consumers could see it for what it is, a piece of junk. Stay sway. I wish I would have purchased the Stinger Amp which has similar specs and much better reviews. ... show more
Reviewed in the United States on November 25, 2025 by _Me
    • Good quality great sound
Size: 500 Watt RMS Class D Monoblock
Scar is a great brand. I’ve had several amps from scar and subwoofers right now I’m using the 500.1 to power a kicker comp 12 and it absolutely slams. The 2 A I had before were kicker 1200.1 I had those pushing to EVL 12s one each never had a problem with any of my scar equipment even the scar 6 1/2 two ways I have in my doors great sounding speakers ... show more
Reviewed in the United States on July 3, 2025 by Wesley force jr.
    • Better than most.
Size: 500 Watt RMS Class D Monoblock
This is alot of amp in a small package. Handles 1 ohm load and barely gets warm after an hour of my teen blasting his bass. Would buy again and highly recommend.
Reviewed in the United States on May 13, 2025 by rfichtner2
    • Works great
Size: 500 Watt RMS Class D Monoblock
Bought this to go with Skar's 10" Toyota Tacoma sub box (with included sub) and it powers it great. Installation was easy and straightforward. Doesn't get hot, small size - easy to install basically anywhere, and best of all it is 1 ohm stable (like their sub requires). Only owned and had installed for 2 weeks so if there are any issues I will update this review ... show more
Reviewed in the United States on July 25, 2024 by Quiksilver2101

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