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Fosi Audio

Fosi Audio M04 Subwoofer Amplifier for Home Theater Mono Channel Digital Class D Integrated Power Amp for Passive Speakers Subwoofer Rated 100W MAX

    • Based on 248 reviews
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Availability: In Stock.
Fulfilled by Amazon
Arrives Tuesday, May 21
Order within 22 hours and 13 minutes
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Features

  • The Fosi Audio M04 is a mono amplifier designed for driving passive subwoofers or speakers. It features the Texas Instruments TPA3116 chip and NE5532 op-amp, providing an output power of 100 watts for a 4-ohm subwoofer or speaker.
  • The M04 SUB amp is designed to improve the bass response of passive subwoofers. It features a selector switch that allows the user to switch between subwoofer bass amplifier and full-frequency mono amplifier modes.
  • The mono amplifier home audio has a small and robust design with a built-in low pass filter for subwoofers and a sub frequency control, making it practical and powerful. It uses highly efficient Class D technology that remains cool under demanding loads and doesn't take up much space.
  • The mini subwoofer amplifier can produce a deep, crisp, and clean low-frequency sound effect, making it an excellent addition to dedicated home theaters. It has been designed to enhance the sound and performance of your audio system at an affordable price.
  • What You Get: M04 subwoofer amp x1, 19V/4.74A power supply x1, user manual x1, our worry-free 24-month warranty, as well as friendly customer service.

Item Dimensions LxWxH: 5.2 x 3.5 x 1.4 inches


Voltage: 110 Volts (AC)


Manufacturer: tp-01


Brand: Fosi Audio


Number of Channels: 1


Product Dimensions: 5.2 x 3.5 x 1.4 inches


Item Weight: 7 ounces


Item model number: M04


Is Discontinued By Manufacturer: No


Date First Available: January 18, 2018


Manufacturer: tp-01


Country of Origin: China


Frequently asked questions

If you place your order now, the estimated arrival date for this product is: Tuesday, May 21

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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Top Amazon Reviews

    • 5.0 out of 5 stars excellent for driving a center spkr
bought it to drive a center channel spkr from the line output of an ancient (90s) matrix surround decoder, and it produces ample volume with the potentiometer at the 12 o'clock position in my 10 x 12 listening space. I am very pleased with all Chi-fi stereo equipment I have bought since 2015, highly recommended. ... show more
Reviewed in the United States on May 31, 2023 by elarrecostao
    • 5.0 out of 5 stars Easy to set up and works well.
My 100W built in sub amp started having trouble. I decided to try this amp. It worked well and sounds good but I need to run it at almost full volume to hear it. Wished it had a little more power but the volume is OK for the room I have it in.
Reviewed in the United States on April 26, 2023 by M. Ray
    • 5.0 out of 5 stars Pushes a Polk Audio PSW505 12" just fine.
The amp in my PSW505 died like it was obviously designed to do from the factory. I was skeptical that this little thing would be able to do the job. Just looking at the size of most of the plate amp guts made me even more skeptical. I decided to pull the trigger anyway and have not been disappointed. No hiss or humm like with the old plate amp. The sound is clean. I do have it cranked to max and the xover at the 10 o'clock position for my tastes. I ran LFE from my receiver to the left RCA input on the amp and it gets plenty of signal. Don't throw out those old subs guys! If you have a PSW505 most likely the sub is fine and that junk amp just has bad caps and other components in it. This fix was cheaper and less time consuming that having the old plate amp repaired. ... show more
Reviewed in the United States on February 17, 2023 by Turd Ferguson
    • 5.0 out of 5 stars This little banger, bangs!
Using this little beast for a music only 2.1 setup. Paired it with a Fosi DA-2120A with some Klipsch RP-160Ms and a pair of GRS 8ohm 12" subs wired for 4ohm in a sealed box. Couldn't be happier. This amp powers the subs with ease and pressurizes my room nicely. You can feel the kick drum in your chest. The volume knob on this amp is literally only turned to about 3 and it's as much bass as I need. I'm not a bass head and mainly listen to hard rock/metal so sealed subs are my go to for music. This little banger is all I need to keep banging hard! ... show more
Reviewed in the United States on March 21, 2023 by M.J. Shearer
    • 4.0 out of 5 stars Works well to power my sub
I purchased this for the subwoofer I have in my garage. I had purchased a replacement system when my previous one failed and it didn’t have enough power for the sub. This did the trick. It drives the sun very well, has its own volume control, so I can decrease it at night if I want, or turn it up when I workout. Would purchase again if needed. ... show more
Reviewed in the United States on December 7, 2022 by BMart
    • 5.0 out of 5 stars Nifty Little Amp - and it works!
I recently upgraded a low-budget A/V system located in a technically challenging environment - an attached greenhouse with hot tub. The previous system's receiver had a built-in amp. for the passive sub. The "new" (relocated) receiver has only line-level sub outputs, so this amp. was an obvious choice to close the "gap". I can make all the speaker and sub. adjustments including level and cross-over frequency in firmware, but it's quite convenient to have the sub volume easily adjustable on the unit itself as various sources need to be tweaked. As far as I can tell, the input jack is mono only so the mono 3.5mm plug to RCA adapter cable I bought works fine. (The photo the supplier provides in the product description shows a stereo 3.5mm plug at the input and the related consumer questions/answers on this topic are unclear.) When I first connected the system I had no sound out, but the issue was quickly traced to the speaker settings in firmware where I had declared the front L/R speakers as "Large". They need to be set to "Small" to get audio to the sub. I set the sub level in firmware to +5dB and the crossover freq. to 90Hz, but that latter will need some additional tweaking. At first experience the audio is great! Good, thunderous bass without overdriving the sub...more than I expected from this cheap system!. The unit runs cool to the touch and shows no evidence of being stressed in any way. I expect it to last a long time!. A couple of suggestions for the manufacturer: 1) consider using a less bright LED as the power on indicator - the current one is almost blinding in a darkened environment, as others have reported (the LED is dim when the volume control is switched to the OFF position then becomes very bright when switched ON) - and; 2) consider providing a standby mode when no audio signal is sensed (system power-down) like powered subs provide. I guess this latter is moot since the attached power supply would always be active and pulling some minimal power any time it's plugged-in. Otherwise, so far this seems to be a great product that will serve me well for many years...! ... show more
Reviewed in the United States on January 23, 2019 by B. Helms
    • 4.0 out of 5 stars So Far, So Good
I'm using this amp to power a 1990 Bose Acoustimass 3 passive sub, 5-1/4" driver. The driver has dual 8-ohm coils, so I jumpered the inputs in parallel to give the amp a 4 ohm load. I'm in shock at how well this setup works. In the adjacent corner of my living room, I have a Sony 15", 200 watt sub, and down to 40 Hz, this little beast keeps up with the Sony. Very good transient response. It can make the room resonate with the Sony sub turned off, and this listening area is probably 3 times the cubic feet recommended for such a small sub. I have no idea what the RMS output is, I'll bet it's 50W or less, but it's plenty of power for the tiny Bose sub at my listening levels, which rarely go above 85 dB. Class D is nice. Stays cool, doesn't eat a lot of power. I experienced a few negatives as other reviewers mentioned. When I hooked it up stacked on top of a Kinter K2020A+ amp, there was 60 Hz hum feeding to the sub. Didn't matter if it was near the Kinter or not. Then I noticed the hum disappeared when I grabbed hold of both amps with my hand. A jumper wire between chassis screws on the amps fixed it. The power LED is ridiculously bright. It took 4 layers of 1st aid tape to tame it. It would be nice if it had a power switch separate from the volume control, so you don't have to fiddle with the volume setting every time you turn it on (with my 2-sub setup, it doesn't sound right unless both subs are at exactly the same level). But that's a minor complaint. Plugging it into a switched power strip with some of my other stuff takes care of that. We'll see how long it lasts. If it outlasts the 18-month warranty by a few years, good deal. ... show more
Reviewed in the United States on August 29, 2018 by Mickey B

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