Fosi Audio HT4S Bluetooth Amplifier for Outdoor Speakers, 4 Channel Power Amp for Home Theater, Outdoor Gathering, 4.1/5.0 Ch Stereo Home Audio Receiver, Supports AUX/Optical Input with Remote Control
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Availability:
20 left in stock
Arrives
Thursday, Jul 23
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Features
- All-in-One Amp: A mini amplifier that integrates DAC and power amplification. This stereo amplifier supports up to 5 channels output, switchable between 4.1 and 5.0 channels. It features Bluetooth, AUX, and optical digital inputs, along with pre-out and support for up to 5 speaker outputs. Note: The HT4S is a stereo amplifier and does not support Dolby, DTS, or other multichannel surround sound modes
- Multi-Scenario Solution: Ideal for pairing with outdoor speakers or wall-mounted speakers, perfect for setting up 2 to 5-channel audio systems in environments like patios, cafes, restaurants, bars, etc. It can also serve as a home theater or desktop HiFi system amplifier, meeting your diverse needs from indoor to outdoor settings
- Enhanced Immersion: Take your sim racing and home theater experience to a whole new level! By pairing with bass shakers, its sufficient power output and bass boost help significantly enhance the realism of racing simulator games. When watching movies at home, the vibration feedback can also help you experience your movies in another dimension, making every movie feel more realistic like being in a cinema
- Effortless Operation: Featuring a comprehensive user-friendly design with a built-in power supply, accompanied by remote control, supporting bass and treble tone adjustment, a multifunctional central knob for volume control, powering on/off and mode switching, LED mode indicator ambient light, etc. Enjoying music has never been easier
- Elegant and Durable: Continuing Fosi Audio's tradition of an all-aluminum alloy body design, the CNC unibody construction and fine metal sandblasting process highlight a minimalist aesthetic
Manufacturer: Fosi Audio
Brand: Fosi Audio
Mfr Part Number: HT4S
Model Number: HT4S
Unit Count: 1.0 Count
Warranty Description: 24-month manufacturer
Built-In Media: Fosi Audio HT4S; Power Cord; Bluetooth Antenna; 3.5mm Aux Cable; Remote Control
Frequently asked questions
If you place your order now, the estimated arrival date for this product is:
Thursday, Jul 23
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.
To initiate a return, please visit our Returns Center.
View our full returns policy here.
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Top Amazon Reviews
Just got this Bluetooth amplifier/receiver and I am beyond impressed. Setup was insanely easy — paired to my TV and phone within seconds — and the sound quality is on a totally different level. The clarity, bass response, and overall power this little unit puts out shocked me. It instantly upgraded my detached garage man cave and made movies and music feel immersive and clean. Bluetooth connection is rock solid with no drops, the controls are simple, and the build quality feels premium. I also love that it gives me the flexibility to run speakers without dealing with a huge bulky receiver. If you’re looking for a compact amp that delivers big performance, this is the one. Absolutely worth every penny — can’t believe I waited this long to get one!
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Reviewed in the United States on December 10, 2025 Reviewed in the United States on December 10, 2025 by Joshua
TLDR: If you're looking for a beautifully built, excellent sounding bluetooth amp this is the one. It excels in audio clarity with little to no distortion at high realistic listening volumes, offers multiple audio input modes that you can select between with a convenient remote, and has the most output channels of any bluetooth amp for this price point. An absolute MUST BUY for any one in the market for a small nice amp. Right out of the gate, this new Fosi Audio bluetooth amp is absolutely amazing. The build quality and design are top notch given the price of this amp. Really hard to beat especially when compared to other similarly priced amps on Amazon. Rated at max power of 50watts per channel at 4ohms, this thing has enough power to realistically handle any speakers you throw at it given its use case. I tested these on my Wharfedale Evo 4.2 bookshelf speakers (these are no slouch!) and WOW what a difference in audio quality over my $1k Denon AVR for music. The DAC on this bluetooth amp is shockingly very clear and defined, definitely ideal for music. Added with the tone controls on the front of the amp, this amp is more versatile than ever. I've got 2 other models of Fosi Audio amps, and this is by-far superior to the other older models that I've got. It's got much better clarity and doesn't distort at higher volumes in comparison to the TB10D that I have. One of my favorite improvements over the previous model bluetooth amps from Fosi is that this new HT4S model has the ability to select your audio input mode. I can now swap between bluetooth on my phone for music and optical/aux in from the TV/Apple TV. On my older bluetooth amp from Fosi it was an on/off switch control and that was it. Both bluetooth and aux were active at the same time. So if I was watching something via the TV somebody else could bluetooth freely and play music over my TV audio which was very frustrating. With this new HT4S model that issue is now gone and the beautiful LED light bar on the front panel displays which audio mode you're currently in by changing colors.
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Reviewed in the United States on September 4, 2024 Reviewed in the United States on September 4, 2024 by Kenny Vannavong
Sounds great but when I want to hire the volume with the remote it changes the input setting. So I need to get up and fix everything
Reviewed in the United States on May 15, 2026 Reviewed in the United States on May 15, 2026 by Jaime Perez
So many reviewers say the amp lacks power. I am using the Fosi HT4S for a bedroom setup with a pair of ancient Dynaco A10 speakers. They are reasonably efficient, so the power output is enough to fill the room with quite enough sound. Initially fed the Bluetooth from my iPad Air. The sound was ok for Bach choral music, but I decided to borrow the WiiM miniature from my primary system. The sound was notably improved over the Bluetooth. I have an entry level Sony subwoofer which will be connected in a couple of days. I have been so pleased with the Fosi products that I am replacing my Yamaha integrated receivers to reduce size and to add additional capability (optical for the HT5S and coax for the ZH3 and ZD3). The HT4S provides just the right amount of connectivity for this bedroom setup and the price was right. As per Amazon, I found a combination HDMI switcher and audio extractor to handle the Roku and Sony DVD/CD player.
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Reviewed in the United States on October 12, 2025 by JRCross
Okay. Let me address the power. It is right at the cusp of being underpowered. But for my set up it is not. With my set up it is at the perfect level. Powering 4 Kicker KB6B’s it is just right for my patio pool area. PLENTY OF VOLUME. The speakers sound amazing and absolutely no distortion. I love the sound and the volume level. Could it be louder? Yes but it works perfectly with my set up and it is plenty loud. I have never needed more and been disappointed that it could not produce it. The ease of set up and the sound it produces is excellent. Crystal clear through all ranges. Plenty of power. No distortion. No issue with Bluetooth drop out. Have my outdoor TV connected by optical cable. Nice easy no frills set up. Combine this with an eq app if you need more out of the sound for your speakers but it is perfect with what I have. To my ears. No issues with the remote and my existing TV. Works great. I would highly recommended this amp for outdoor speakers and TV for a patio area. I love it.
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Reviewed in the United States on August 24, 2025 by Christopher
Bass is too low, even turned all the way up. This is not 5.1 at all, just 2.0 shared across all connected speakers. Worst part of all, and why i chose to return, the controller WILL interfere with a TV nearby and in random ways. The volume up changes the input on my TV. Can you imagine that? Its unusable because of the smallest defect they cannot address other than to say point it away from my TV. Just not possible. The mute button literally turns off my TV. Shame, had promise
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Reviewed in the United States on December 19, 2024 by Liquiddag
This thing is fantastic and works great. I had a little blue-tooth amp that would power two speakers. But, I had four total that I wanted to connect (older RCA/Optimus LXII 5, Linaeum Tweeter bookshelf speakers). So, I originally purchased one of those Pyle receivers (https://www.amazon.com/gp/your-account/order-history?ref_=ya_d_c_yo) but it was DOA and I returned it. I got this as a replacement and couldn't be happier. Right out of the box, it works great, sounds great (would be better if I connected a sub), and it's got a nice, low footprint. I am very happy with this unit.
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Reviewed in the United States on April 7, 2026 by Christopher Garner
I have to say this is a cool little amplifier. Very nice minimalist appearance and very compact. Appears to be well made with a nice assortment of audio inputs. The remote is very handy and functional. The Fosi Audio HT4S isn’t earth shaking but it drives my set up to where it needs to be. I have this connected to my PC via TOSLink and driving two vintage Sansui LM-110 Speakers. It is almost perfect for my needs. Unfortunately I’ll be returning this as soon as I can figure out a suitable replacement. The ad on Amazon clearly states that; “The HT4S does not support automatic power on/off and requires manual operation or the use of the remote control to switch on/off.” This is incorrect, tech support told me today that this amplifier shuts off after fifteen minutes of no audio. For me this is a deal breaker. My PC stays on most of the time and I want it ready for use when I want it without having to turn everything on. For some this won’t be a problem and may even be a feature they like. Not for me though. What a shame, otherwise I like it.
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Reviewed in the United States on September 18, 2025 by jluvs2ride