Fosi Audio SW10

A compact powered subwoofer to partner the SP601

The Fosi Audio SW10 is a compact powered subwoofer built around a 10-inch down-firing woofer and a 200W Class-D amplifier rated for 500W peak. The driver fires toward the floor — using the floor as a natural reflector to spread bass more evenly — and the cabinet is ported by a pair of rear bass ports for greater airflow and deeper extension. The front face is left clean, with the driver hidden underneath and all the controls on the rear, giving it a Nordic-inspired minimalist look that disappears into a room.

Fosi pitch it as a do-everything subwoofer for movies, music and gaming, designed to partner their own amplifiers and speakers — and it slots in naturally beneath a system like the Fosi Audio SP601 speakers, which is exactly how I have been using it. A precision DSP adds DRC limiting and dual EQ voicings, and the rear panel carries a proper 40–180Hz crossover and 0–180° phase control for integrating it with the main speakers.

Unboxing and Packaging

The SW10 arrives in a plain Fosi Audio shipping carton — “Redefining HiFi with Unmatched Value” printed on the side:

Inside, the subwoofer is bagged and wrapped in protective film:

The accessories are minimal — a power cable and the SW10 user manual:

Freshly unboxed and wrapped, sitting in the room next to the SP601 system:

Design and Build Quality

The SW10 is a clean, minimalist white cube with rounded edges and no visible driver on the front or sides — understated enough to sit unobtrusively in a living room. It is a substantial unit, with a 14kg MDF cabinet finished in PVC, and that mass is deliberate: it helps damp cabinet resonance and vibration for cleaner bass:

The 10-inch woofer is down-firing, mounted on the underside and lifted off the floor by four feet so it can fire toward the floor surface:

The rear carries the dual flared bass ports above the amplifier plate:

For a sense of scale, here it is next to a KEF subwoofer — the SW10 is the noticeably larger of the two:

Controls and Connections

The amplifier plate on the rear is well equipped for a subwoofer at this level. There are rotary controls for crossover frequency, phase and volume, RCA input and output, an LFE / Line-in selector, an EQ1/EQ2 voicing toggle, and an auto-power (On/Auto) switch alongside the main power switch:

Seen at an angle, with the woofer below:

A closer look at the RCA input/output, the LFE/Line-in switch and the auto-power toggles:

The controls are comprehensive for a sub at this price. The crossover is continuously adjustable from 40Hz to 180Hz, so you can dial in exactly where the SW10 hands over to your main speakers, and the phase control sweeps the full 0–180° for time-aligning it with them. The EQ1/EQ2 toggle switches between two DSP voicings, and behind the scenes the DSP also applies DRC limiting to keep the driver under control during dynamic peaks rather than letting it overload. Connection is by RCA line input or a dedicated LFE/subwoofer input for home-theatre use, with an RCA line output to daisy-chain a second sub or amplifier. The auto-power circuit senses an incoming signal and switches the sub on and off automatically, so it idles down when the system is quiet.

In the System

The SW10 slotted into my TV and desktop system alongside the SP601 speakers, adding low end beneath them:

It also formed part of my larger hi-fi setup with the turntable and headphone gear:

As with the rest of this setup, I used the WiiM’s RoomFit room correction (here with the KEF LS50 and the Fosi subwoofer) to integrate the sub cleanly into the room:

Sound Impressions

Sound impressions to follow.

Specifications

Rating Explanation

Conclusion