Fosi Audio M04 Subwoofer Amplifier for Home Theater Mono Channel Digital Class D Integrated Power Amp for Passive Speakers Subwoofer
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Availability:
In Stock.
Arrives
Saturday, Sep 6
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Features
- High-Performance Mono Amplifier: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 2-ohm subwoofer or speaker.
- Enhanced Bass Response: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.
- Compact and Robust Design:This mini amp 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.
- Superior Sound Quality:The home subwoofer amplifier can produce a deep, crisp, and clean low-frequency sound effect, making it an excellent addition to dedicated home audio receivers & amplifiers. It has been designed to enhance the sound and performance of your audio system at an affordable price.
- Complete Package:What You Get: M04 subwoofer amp x1, 19V/4.74A power supply x1, user manual x1.
Item dimensions L x W x H: 5.2 x 3.5 x 1.4 inches
Voltage: 230 Volts
Manufacturer: Fosi Audio
Brand: Fosi Audio
Number of Channels: 1
Item dimensions L x W x H: 5.2 x 3.5 x 1.4 inches
Voltage: 230 Volts
Manufacturer: Fosi Audio
Brand: Fosi Audio
Number of Channels: 1
Output Power: 1E+2 Watts
Specification Met: [Inf] Thd <= 0.04% and Frequency Range 20hz - 120hz
Product Dimensions: 5.2 x 3.5 x 1.4 inches
Item Weight: 15.9 ounces
Item model number: M04
Is Discontinued By Manufacturer: No
Date First Available: January 18, 2018
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If you place your order now, the estimated arrival date for this product is:
Saturday, Sep 6
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View our full returns policy here.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
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Top Amazon Reviews
Got this subwoofer amp to bypass the amp component of my active subwoofer which died months ago due to a peak in voltage. My amp was those that work in "stand-by" mode, so they are always powered up somehow. Replacing the board with a new one (original) was too expensive, even more expensive than what the sub costed me in the first place, so in order to not throw the box and the woofer cone to the trash, I decided to just rewire things up in order to bypass the sub's integrated amp, so I got this GREAT little FOSI amp to power my "now passive" sub. Things worked great and my sub is now back to life, shining again. The M04 Fosi Amp is a great choice as it is POWERFUL, noiseless (at least to my ear), very small and does not generate any important heat. It comes with a power adapter, so you only need the cables to connect the input signal and the output signal to the passive subwoofer. I used the convenient "bare wire connection" to hook the modified sub to the speaker output of the Fosi Amp. Worked NICELY. Quality of the M04 Fosi AMP is VERY GOOD, in a very neat, compact and ellegant BLACK enclosure. It is definitely worth the money, which is NOT AT ALL expensive, but quality exceeds by far the amount paid for this amp. Until now, i'm really loving it.
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Reviewed in the United States on February 16, 2024 by ASGM
The Fosi M04 Subwoofer Amplifier was purchased as part of a computer speaker system in which the original amplifier "died of old age." The speakers were still good so it made no sense to dispose of them. Since it is not being used in a home theater system, I cannot speak to the full 100 watt output capability. My original computer speaker system (Logitech) is a 5.1 system with the amp inside the subwoofer box. I purchased a six channel amp for the surround speakers and this Fosi 04 amp for the subwoofer. All works well together. Listening to pipe organ music, which can put out some big bass sounds, the amp provides the bass that I need. (I do have a good audio system for music. Amazon has the "frequently returned" warning for this item. That's probably because people order without understanding what they need, not because the product is inferior. It produces lows from 20Hz. The item was packaged very well with foam and an attractive box, with a factory seal. I would place this in the excellent category of quality and price. (It's not junk) and has an 18 month warranty. Of course I have decades of experience building electronic devices and knew what I wanted for the purpose and budget
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Reviewed in the United States on April 9, 2025 by BW
5 stars if they supplied the larger power brick. I bought this because I have another I purchased to replace a blown sub amp. Seeing it is operable in full range mode and always wanting to try mono-blocks I felt this was the cheap way to do it and honestly it was worth it.
Reviewed in the United States on May 30, 2025 by Amazon Customer
Purchased this to use with an old passive subwoofer from a stereo system that went bad. It was easy to set up and works perfectly, sounds great and brought new life to an otherwise perfectly good subwoofer!
Reviewed in the United States on January 25, 2025 by RY
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...!
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Reviewed in the United States on January 23, 2019 by B. Helms
Easy to wire and the frequency and volume adjustments work well with good control over the levels. I'm using it to power an old subwoofer that the original receiver died on and the replacement receiver does not have a sub output built in. It brought the old sub back to life, even better than original.
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Reviewed in the United States on May 27, 2025 by Matt
I purchased this to power passive the sub woofer on a Panasonic 3-speaker system I picked up at Goodwill. Great little unit, and powers the sub just fine. It is small, inconspicuous and easy to connect. Plenty of power for my office setup, easy to use and adjust quality and output levels to go along with my listening choices. This unit meets my needs for the speakers I have, and I am not disappointed.
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Reviewed in the United States on May 25, 2025 by boboprf
Performance: Don't waste your money on this device. Noisy and you don't get the performance you REALLY want. Buy a Nuofuwei DC 12V 1000W Power Supply ($77) and connect it to a car amp of your choice, it will handle up to 1000W Amp. and have fun shaking your house.
Reviewed in the United States on June 30, 2025 by Mariko