Fosi Audio BT30D 2.1 Bluetooth Amplifier
- 2.1 channel Class D amp, two TPA3116D2 chips
- Up to 200 watts maximum output
- Bluetooth 5.0 up to 50 feet, RCA input
- Sub volume and frequency, bass and treble controls
- Drives passive speakers, passive or powered subwoofer
- 24V/4.5A power supply included, 18-month warranty
Last refreshed Jun 20, 2026 · Based on the Amazon listing and published specifications, not hands-on testing.
A small amplifier that adds Bluetooth and a subwoofer channel to a pair of passive speakers. It has no HDMI or optical input, so it suits music and desktop setups more than TV sound.
As an Amazon Associate I earn from qualifying purchases. ProductDome earns a commission when you buy through links on this page.
ASIN: B07K7NJ4QNModel: BT30DCategory: Stereo Amplifiers
Overview
A desk, a garage workshop or a patio speaker setup suits this Fosi amplifier, which powers two passive speakers plus a subwoofer from Bluetooth or RCA sources. Front knobs set bass, treble and subwoofer level and crossover.
Adding a sub channel and tone controls to a palm sized amp makes a full range system from bookshelf speakers in very little space. Inputs stop at Bluetooth and RCA, which leaves TVs with only optical or HDMI out without a direct link.
Who it's for
Hobbyists building a bookshelf speaker system with a sub for music from phones and computers. TV owners needing digital inputs should look at an amp or receiver with optical or HDMI.
Pros and cons
- Dedicated subwoofer output
- Bluetooth plus RCA input
- Bass, treble and sub controls
- Power supply included
- No optical or HDMI input
- Per channel power figures unclear
- No remote control listed
Performance notes
Class D chips switch at high frequency for efficient output with little heat, which is why the unit stays small. Usable power depends on speaker impedance and the supply, so the maximum figure is a peak rather than continuous output. The sub crossover splits low bass away from small main speakers.
Specifications
| Brand | Fosi Audio |
|---|---|
| Model | BT30D |
| Dimensions & fit | |
| Item weight | 1.1 Kilograms |
| Capacity & performance | |
| Maximum Output Power | Up to 200 watts |
| Power & efficiency | |
| Power Source | 24V/4.5A power supply (included) |
| Warranty & support | |
| Warranty Description | 18-month manufacturer |
| Other details | |
| Wireless Technology | Bluetooth 5.0, up to 50 feet |
| Control Type | Sub volume, sub frequency, bass, treble |
| Number of Channels | 2.1 |
| Amplifier chips | 2 x Texas Instruments TPA3116D2, Class D |
| Inputs | Bluetooth, RCA |
| BuiltIn Media | BT30D amplifier, 24V/4.5A power supply, user manual |
Frequently asked questions
Can the Fosi BT30D connect to a TV optical output?
No. It accepts Bluetooth and RCA inputs only, per the listing.
Can the Fosi BT30D power a passive subwoofer?
Yes. It drives passive and powered subwoofers, with adjustable sub volume and frequency.
Is a power supply included?
Yes, a 24V/4.5A power supply.
How far does Bluetooth reach?
Up to 50 feet.