Fosi Audio HT4S 4 Channel Bluetooth Amplifier
- Up to 5 speaker outputs, switchable 4.1 or 5.0
- Bluetooth, AUX and optical inputs, built-in DAC
- Pre-out for a powered subwoofer
- Bass and treble controls, remote included
- Built-in power supply, aluminum CNC body
- No Dolby or DTS decoding
- 24-month warranty
Last refreshed Jun 20, 2026 · Based on the Amazon listing and published specifications, not hands-on testing.
A compact multi-speaker stereo amp for patios, cafes and sim racing rigs with Bluetooth and optical inputs. It does not decode surround formats, and output power is not listed.
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ASIN: B0CYQ1B598Model: HT4SCategory: Stereo Amplifiers
Overview
A patio, a cafe or a sim racing corner is where this Fosi amp works, driving up to five speakers from one aluminum box with Bluetooth, AUX and optical inputs. A remote, tone controls and a central knob handle daily use.
Running several outdoor or wall speakers from one small box with Bluetooth makes zone audio simple. It plays stereo to every speaker and does not decode Dolby or DTS, so it is not a surround receiver.
Who it's for
Homeowners wiring outdoor speakers, small shop owners and racing sim builders with bass shakers get multi-speaker power. Home theater fans who need surround decoding need an AV receiver instead.
Pros and cons
- Drives up to five speakers
- Bluetooth plus optical and AUX
- Remote and tone controls
- Built-in power supply
- No Dolby or DTS decoding
- Output power not listed
- Speaker impedance range not listed
Performance notes
The built-in DAC converts optical and Bluetooth signals before amplification, so a TV or phone feeds it directly. In five-channel or four-plus-sub modes it sends stereo to every output rather than separate surround channels. Bass boost helps when driving shakers.
Specifications
| Brand | Fosi Audio |
|---|---|
| Model | HT4S |
| Capacity & performance | |
| Outputs | Up to 5 speaker outputs, pre-out |
| Audio Output Mode | Stereo, no Dolby or DTS |
| Power & efficiency | |
| Power Source | Built-in power supply |
| Construction & materials | |
| Enclosure Material | Aluminum alloy, CNC unibody |
| Compatibility & installation | |
| Connectivity Technology | Bluetooth, AUX, optical |
| Warranty & support | |
| Warranty Description | 24-month manufacturer |
| Other details | |
| Control Type | Remote, central knob, bass and treble |
| Number of Channels | Up to 5, switchable 4.1 or 5.0 |
| BuiltIn Media | HT4S amplifier, power cord, Bluetooth antenna, 3.5mm aux cable, remote control |
Frequently asked questions
Does the Fosi HT4S decode Dolby or DTS surround?
No. Fosi states it is a stereo amplifier and does not support Dolby, DTS or other multichannel surround modes.
How many speakers can the Fosi HT4S drive?
Up to 5, switchable between 4.1 and 5.0 setups.
Can I connect my TV to the HT4S?
Yes, through the optical digital input or AUX.
Does the HT4S need an external power brick?
No. It has a built-in power supply and comes with a power cord.