Fosi Audio HT4S
- Fosi Audio
Fosi Audio HT4S
- Fosi Audio
$156.47
- Authorized Dealer · Tech Support · 30-Day Returns
Why it stands out
Best for
Not ideal for
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Setup guide
How to connect
What you should know
EMiUZEK buying notes
Frequently asked questions
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Official product information provided by Fosi Audio
The following product descriptions, specifications and images are provided by the manufacturer.
Fosi Audio HT4S is a compact 4.1/5.0-channel integrated amplifier for multi-speaker, outdoor-audio and simulator systems.
Bluetooth, optical and 3.5mm inputs, five amplified channels and a switchable sub/center channel create a flexible multi-speaker system without a full-size AV receiver.
Why it stands out
Switchable 4.1 or 5.0 operation
Configure four main speakers plus a subwoofer channel, or use five full-range speaker channels.
Built-in multi-channel power
Provides four 30W channels plus a 60W sub channel in 4.1 mode, or five 30W channels in 5.0 mode.
Digital and wireless inputs
Connect optical PCM, 3.5mm analog or Bluetooth sources.
Remote and front-panel control
Adjust source, volume, tone and operation without a separate controller.
Best for
- Outdoor and patio multi-speaker systems
- Sim-racing bass-shaker installations
- Compact 4.1 or 5.0 speaker systems
- TV systems with optical PCM output
Not ideal for
- Dolby or DTS surround decoding
- Systems requiring HDMI ARC
- Speakers below the specified 4Ω minimum
EMiUZEK Buying Notes
- HT4S is a multi-channel amplifier, not an HDMI adapter or surround-sound decoder.
- Set the source to PCM stereo when using optical; encoded Dolby/DTS signals are not supported.
- The SUB/CEN output changes function with the selected mode, so confirm the switch setting before connecting speakers.
Frequently asked questions
Does HT4S have HDMI?
No. Inputs are Bluetooth, optical and 3.5mm AUX.
Does it decode Dolby or DTS?
No. Use a compatible PCM signal.
Can it run five passive speakers?
Yes, in 5.0 mode with compatible 4–8Ω speakers.
Can it power a passive subwoofer?
Yes, in 4.1 mode through the dedicated amplified SUB/CEN channel.
Does it have a line output?
Yes, a 3.5mm pre-out is provided.
Can it be used outdoors?
It can power outdoor speakers, but the amplifier itself should remain protected indoors.
HOW TO CONNECT
Optical TV system
Source icon: tv
Source: TV / projector
Connection: Optical PCM
Output connection: Speaker terminals
Target icon: speakers
Output: Four or five passive speakers
Outdoor multi-speaker system
Source icon: phone
Source: Phone / streamer
Connection: Bluetooth or AUX
Output connection: Speaker terminals
Target icon: speakers
Output: Outdoor passive speakers
Sim-racing system
Source icon: computer
Source: PC / simulator audio
Connection: Optical, AUX or Bluetooth
Output connection: Speaker and SUB/CEN outputs
Target icon: speakers
Output: Speakers and compatible bass shaker / passive subwoofer
Technical Specifications
Connections
| Feature | Specification |
|---|---|
| Inputs | Bluetooth; optical; 3.5mm AUX |
| Outputs | Five speaker channels; 3.5mm pre-out |
| Speaker impedance | 4–8Ω |
Amplification and physical
| Feature | Specification |
|---|---|
| 4.1 rated output | 30W × 4 + 60W × 1 @ 4Ω |
| 5.0 rated output | 30W × 5 |
| Maximum output | 50W × 5 @ 4Ω |
| SNR | ≥88dB |
| THD | ≤0.03% |
| AC input | 110–240V |
| Dimensions | 6.1 × 7.2 × 2 in |
Additional Product Content
Comparison: Which Fosi Audio model is right for you?
| Model | HT4S | BT30D | BT30D Pro |
|---|---|---|---|
| System type | 4.1 / 5.0 multi-speaker | 2.1 stereo | Higher-output 2.1 stereo |
| Digital input | Optical | None | None |
| Amplified outputs | Up to five channels | Stereo + passive subwoofer | Stereo + passive subwoofer |
| Maximum stated output | 50W × 5 @ 4Ω | 50W × 2 + 100W | 165W × 2 + 350W @ 4Ω |
| Best use | Outdoor, sim racing, multi-speaker | Compact moderate-output 2.1 | Higher-output 2.1 |
What's in the box, manuals and downloads
Shipping, warranty and returns
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