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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: 13 left in stock
Fulfilled by SKAR AUDIO
Arrives Monday, Jul 13
Order within 6 hours and 11 minutes
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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)


Voltage: 14.4 Volts


Maximum Supply Voltage: 14.4 Volts


Minimum Supply Voltage: 14 Volts (DC)


Mounting Type: Surface Mount


Number of Channels: 4


Output Power: 400 Watts


Maximum Output Power: 400 watts


Item Dimensions: 7.9 x 4.64 x 1.65 inches


Material Type: Mosfet


Manufacturer: Skar Audio


Model: SK-M4004D


Brand Name: Skar Audio


Warranty Description: 2 year limited warranty


Global Trade Identification Number: 65


UPC: 739189979165


Part Number: SK-M4004D


Item Type Name: Car Amplifier


Item Weight: 3.7 Pounds


Included Components: Skar Audio SK-M4004D Compact Full-Range Class D 4 Channel Amplifier


Unit Count: 1.0 Count


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Monday, Jul 13

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
    • No wine and no popping when turning on and off
Size: 400 Watt RMS Class D Four Channel
Very impressed with the clarity and sound from a no name amplifier we’ll see how it holds up
Reviewed in the United States on April 8, 2026 by Darrkon
    • small but powerful
Size: 400 Watt RMS Class D Four Channel
I bought this for a stereo retrofit project on my 1987 BMW 635Csi. Its a good little amp; puts out a ton of power in a small package. No problems installing it, pretty basic. Minor issue : fan mounted on the bottom so you need to stand it off the mounting surface just a bit. Some have said it gets hot but mine does not at all.... as long as you let some air in/out of the bottom surface vents it's entirely cool. Would definitely purchase it again. ... show more
Reviewed in the United States on February 4, 2024 by Bkewc
    • 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
    • Bought 2, both started cutting out and both stopped working
Size: 400 Watt RMS Class D Four Channel
I bought this amp a few years back. I had it on my main four speakers. I loved the sound, the look, everything. A year or so later it started to cut out. The sound would just drop out, then come back randomly a day or two later. Then it stopped all together and I could only hear my subwoofer. I sent into the company and they sent it back saying it worked fine. I hooked it back up and nothing. I ordered the exact same amp again, plugged in the new one and it worked! That amp lasted 2 years and then started cutting out. Same amp, same problem. I wasted $300 on both of these horrible products. I don't want to waste my time sending them in, if I get the same awful customer service. I have the 350watt mono amp from them an it's never given me problems. If it dies, I'm going with a different company. ... show more
Reviewed in the United States on October 29, 2024 by Bayard Stryker
    • Sized perfectly
Size: 400 Watt RMS Class D Four Channel
Perfect size. When fitted next to a LC5i pro, 2 distro blocks and a mono amp from skar in the same size, it all fits under the drivers seat
Reviewed in the United States on June 30, 2025 by Ernz671
    • Don't need subs with one of these and a good set of speakers.
Size: 400 Watt RMS Class D Four Channel
This amp gave my system just what it needed. I was running brand new cerwin vega speakers directly off my new Android deck via wiring harness and stock speaker wires and it just sounded flat and week. I got this amp and some 16ga speaker wire and rewired the whole car and now it sounds so rich, warm, and powerful. With the eq set to hip hop and the bass boat turned on, you probably don't need a subwoofer. I have a sub in my car and it was overpowering my speakers. This amp does a great job compensating for the bass. It made all the difference in creating a rich full sound and making one of the best sounding car stereos I've ever heard. 10/10 would recommend. ... show more
Reviewed in the United States on April 16, 2021 by Quenten
    • Good
Size: 400 Watt RMS Class D Four Channel
Not a bad little amp. Puts out good power for the price, works well, fairly clear, easy to install.
Reviewed in the United States on February 11, 2025 by Roach

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