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

This is a fantastic little amplifier to drive a passive subwoofer. In the garage I have a Cambridge Audio A1 amp with Q acoustics 1010i speakers. They are great speakers but a little light on bass. Unfortunately the A1 doesn't have active subwoofer output so I've used this to drive a pioneer sub. It's plenty powerful enough drive this, half volume the garage is shaking! The rotary gain and cut off controls are excellent, smooth and precise. Just hope the power supply lasts but all round great value.

Great value subwoofer amplifier for the money, it has a built in adjustable low pass filter which is nice if you want a nice amount of bass but not at the resonant frequency of the room, so you can keep things contained, or to have it come in where your crossover cuts off on your satellite speakers.Good amp.

Very easy to connect . Works perfectly. Gives a good deep bass . Nice and compact. The power supply keeps it working .

Well built, decent amplifier. Happy with any kind of speaker. The built in rudimentary crossover is a nice touch. I would recommend replacing the suspiciously light power adapter with a repurposed laptop charger (also 19v) as this will deliver better sustained high-amperage power to the amp.

I had a Tannoy active subwoofer and the amplifier board started making random rumbling noises.A replacement board would have cost me hundreds.A little bit of rewiring and some amateur woodwork later, the amplifier board is replaced with plywood, speakers wired to new terminals and the little Fosi amp does the heavy lifting.It's not hugely powerful but it by no means struggles to generate the sound levels I require.Job done, money saved.

Awesome little amp, driving my passive sub and is connected to my Denon avr which doesn't have powered sub out.

The media could not be loaded. I bought this to experiment with a new speaker design, so I was looking for something robust, but also something affordable enough where I wouldn't be too upset if I broke it. I've since put this thing through its paces and can honestly say I'm very impressed with the product.Right off the bat, the unit looks great design-wise and feels very sturdy, which was a good sign. But the real value lies in what's inside it.No matter how high you drive the volume, this thing does not clip and maintains a very flat frequency response in PBTL mode. In sub mode, it cuts high-frequency components but actually boosts the bass frequencies up even higher, so you're getting maximum power across the frequency band it's putting out. The sound quality is amazing.In both modes, the amplifier will happily go down to frequencies of about 2 Hz. Below that, it starts to cut out, but this is an order of magnitude below the audible threshold.And finally, I have put this amplifier through some serious abuse over the months I've had it. Think low-impedance coils, dead shorts, making/breaking contacts while it's on - none of that has managed to put a dent in this thing. It doesn't even get warm. Neither the sound quality nor the power output has diminished even slightly despite all that. If something happens that it really doesn't like, it'll just shut off temporarily and try again a few seconds later.Just look at the attached video. That's literally the box the amplifier came in with two magnets and a hand-wound coil, and this thing plays music on it like it's nothing.

On time, Looks good works great Thanks.