The Fosi Audio M03 is a 300W digital mono subwoofer amplifier for home HiFi and home theater systems; this version comes with a 32V/5A power supply. It's for anyone with a passive subwoofer who needs to power it alongside an existing stereo amp or AV setup without buying a whole new receiver.
Who the Fosi Audio M03 is for
Passive subwoofer owners: It gives a passive sub its own amplification, so there's no need for a whole new receiver.
Stereo amp owners adding a sub: Run it next to your existing stereo amp and let it handle low-end duty on its own.
Home theater setups: It slots in beside an AV setup to take over subwoofer amplification.
Shoppers comparing supply versions: This listing includes the 32V/5A brick, which is part of what you're buying, so check the supply when comparing listings.
Skip it if: you need to power a pair of full-range speakers; it's a single-channel amp purpose-built for subwoofer duty.
Fosi Audio M03 key specs
Amplifier type: digital mono
Power rating: 300W
Application: subwoofer (passive)
Power supply: 32V/5A (included)
Color: Black
Genuine Fosi Audio stock. Free shipping on every order, 45-day returns, 1-year warranty.
Fosi Audio M03 vs similar options
vs Fosi Audio V3: Also a mono amp, but built on the TPA3255 with PFFB and bundled with a 48V/5A supply; pick the V3 for monoblock HiFi as well as subs, the M03 for subwoofer duty alone.
vs Fosi Audio BT20A Pro: Drives a stereo pair instead, with 300W x2 from a TPA3255 plus Bluetooth input and bass/treble controls; the M03 is the add-on for a passive sub in an existing system.
Yes. Every unit we sell is genuine and brand-new, shipped in its original packaging, and backed by our 1-year TonePier warranty and 45-day returns.
Where does my order ship from, and how long does it take?
Every order ships from our warehouse in China, with full tracking, and most orders ship within 3 business days. Shipping is free on every order; most US orders arrive within 7–15 business days and most orders to other countries within 7–20 business days — see our shipping policy for details.
What if it isn't for me?
You get 45 days to decide. Keep the packaging, keep it in like-new condition, and send it back for a refund. Ear tips unsealed for hygiene reasons are fine — we expect you to actually listen.
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