WAudio 350W Class-D Subwoofer Plate Amplifier - High Performance Amp Board Module for Subwoofers

I was very excited to receive this, to add it to my ever increasing selection of projects, that I have great passion for, but very little time! Upon arrival, I was pleased by the heft of it. This is a chunky item, and so it should be if its power claims are to be believed. As a self-certified professional amateur electrical engineer, I am over confident in claiming that this looks particularly well put together. The PCB is clean, solder joints look excellent, and cables have been managed thoughtfully and zip-tied in place. I can't add my real-world testing experience as of yet, I will certainly update this review when I can, but if the specs are to be believed, and the manufacturer has included images showing measured values, then this will be a great performer. Perfect for a small/mid sized home cinema with a 12"-15" sub in a properly ported and proportioned cabinet. Personally I plan to use it as part of my Hi-Fi, so I am thinking about driving a couple of smaller punchy subs, 10", in a sealed enclosure. Selection of inputs is nice, you have standard RCA but also balanced XLR. All the controls are reassuringly tactile and solid, nice positive clicky toggle switches and smooth pots. The sub can be set to "wake" upon input. Functionality seems great! In terms of value for money, there is a lot of competition, but this is a level of quality above the typical generic amp. I trust the spec here, and so for a quality 350w plate amp, the current asking price is very reasonable.

- Easy to install and fits well into DIY subwoofer projects - Clean, punchy bass with no noticeable distortion even at higher volumes - Good range of inputs and speaker-level options for flexibility - Built-in crossover and gain controls for easy adjustment - Slight hum in quiet rooms and slight delay in signal kick-in, but overall pleased with performance and price point

I have been using this for a week or so and so far it is performing excellently! I used it to replace the failed amp in my KEF subwoofer which is connected to a Yamaha AV amp. It seems almost better than the original! I did have to make up an adapter plate as this amp is smaller than the original. The only slight negative for me is the brightness of the red standby led, which makes a red circle of light on the wall it sits next to!

Designed for audiophiles, subwoofer enthusiasts, and DIY speaker builders, the WAudio 350W Class-D plate amplifier brings clean, high-powered amplification to your passive subwoofer enclosures, delivering impactful, distortion-free bass. At £180, it's a versatile option for home theater systems, powered subwoofer retrofits, and custom speaker cabinets—offering the core features you'd expect from a professional-grade subwoofer amp. 💪 Power & Audio Performance ✔️ 350W RMS at 4 ohms, providing punchy low-end energy for 10" to 15" subwoofer drivers. ✔️ Class-D amplification ensures energy-efficient operation and low heat output, even at high SPL. ✔️ <1% THD for clean sound, meaning tight, articulate bass with zero muddiness or unwanted distortion. ✔️ Fine-tune your output with adjustable gain, low-pass filter (25Hz–180Hz), and 0°/180° phase switch. 🎛️ Connectivity & Integration ✔️ Balanced XLR and unbalanced RCA inputs for easy integration with AV receivers, DSPs, or preamps—ideal for both home studio and cinema systems. ✔️ Auto-sensing signal detection powers the amplifier on/off intelligently, minimizing energy waste. ✔️ Detachable IEC power cable, external fuse, and 110V/220V voltage selector for global setups. 🧰 Build Quality & Compatibility ✔️ Compact plate design (205×235×65mm) fits most subwoofer box cutouts, great for enclosure upgrades or active DIY subwoofers. ✔️ Onboard thermal, short-circuit, and overload protection ensure long-term reliability for your speaker system. ✔️ Included speaker wire and mounting-ready backplate simplify the retrofit process. ❌ No user-configurable EQ or DSP, but the existing controls offer ample system tuning flexibility. ✅ Final Verdict – A Smart Amp Solution for Speaker Projects & Subwoofer Rebuilds ✔️ Ideal for 12" or 15" passive subwoofers in home audio, studio monitors, or theater sub setups ✔️ Suitable for upgrading failed subwoofer amplifier modules or building your own active subwoofer cabinet ✔️ Capable of delivering clean, controlled low-frequency extension ✔️ Offers big performance in a space-saving, well-protected form factor 👉 Whether you're reviving an old subwoofer or building a new bass beast from scratch, this 350W subwoofer amplifier module has the power and precision to elevate your audio system.

Sometimes I find it hard to get rid of some of my older bits and pieces even if they don't work as they used to just because I can sometimes bring them back to life with a quick fix. Same is this plate on an older subwoofer and once fitted on, not only the subwoofer was brought back to life but it is also more powerful than before. All the wiring is nicely done and the transistors seem to be staying cool and don't cause any issues as this is where I sometimes had problems before. The plate gives good amount of bass and sound adjustment options. It has good connectivity, a decent plate overall.

I fitted this into my DIY sub to see how it stacked up against my usual setup—and I’m impressed. It’s easy to install, feels well made, and delivers plenty of clean, punchy bass. No noticeable distortion even when you push it a bit, and the auto-on feature works exactly as you'd hope—no fiddling with power switches every time. It doesn't quite have the sheer muscle of my current plate amp, but for half the price, that's no surprise—and honestly, it still holds its own very well. A solid option if you're looking for a reliable, well-featured sub amp without spending a fortune. Would happily use it in future builds.

I wanted to put a car sub into a home theater setting for music listening in the garage. Figured I would hook it up to a plate amp. This amp was best bang for buck for its claimed power output. I didn't expect TOO much out of this set up so I built a sub box out of 1/2" osb scrap from work, especially since the sub is dvc wired in series from 2ohm to 4ohm. It's actually performing so well that I now plan to build a proper box out of 3/4" mdf to actually get the full performance out of the amp and sub. This sub is rated at 800w rms btw. I'm impressed with this amp. I've only had it for a month so if it fails I'll come back and update

I swapped out ancient 100w class ab amps for these in my little homebrew living room subwoofers. the power increase is fantastic. the amps run cool. i ran some bass mekanik tracks to run them in hard. i could feel port wind in my chair 15 feet away and the amps kept chugging. no csa, ul, or etl rating on these but the build quality and performance inspire confidence.

Als Austausch für mein defektes Aktiv Subwoofer-Modul in einen HK-TS11. Passt fast perfekt in meinen alten Harman Kardon TS11 Woofer. Ich musste bei der Platine nur die Kanten um 1mm mitm Multitool abnehmen und ich konnte es in das alte Gehäuse einsetzen. Die Leistung reicht bei uns locker für das ca. 30m2 Wohnzimmer. Günstige Alternative zu einem neuen Subwoofer, wenn nur das Modul defekt ist oder zum selbstbau eines Woofers. Die Einstellmöglichkeiten am Woofer sind vielfältig zum Justieren um den Klang für sich einzustellen… Einziger Kritikpunkt, die Auto-ON Schwelle könnte niedriger sein, wenn ich abends nicht zu laut habe, dann schaltet er öfters einfach ab. Das Problem wird aber in zukunft mit einer Master-Slave Steckdose gelöst…

I installed this in a Klipsch R-121SW and although I had to modify the opening slightly I am very pleased with the result. It sounds better than the oem amp. Hopefully it will last longer than the 3 oem amps I had to replace over the last 5 years. I highly recommend this product.

I used this amp to replace a broken one on my Polk audio DSW micropro 3000. I figured going from 1200watts to 350watts would have a significant decrease in performance but I was ok with that. The cost for the original amp didn't make sense. Over all the 350watts was more than an adequate replacement. It works great. I personally cannot tell if there is any difference. The Polk audio sub box is heavy and it does dance around the floor with the new amp. Please note that you may experience a loud hum as many others have mentioned. This is usually due to long subwoofer cable and having the power plug for the subwoofer far away from from the main receiver amp. That hum can easily be removed by putting a simple inline ground loop isolator on the subwoofer cable. Usually they have a left and right channel connections but you just need to connect 1 of the channels and it will work to remove the hum. The filters are typically $20. I used https://www.amazon.ca/dp/B077Y5DLBB?ref_=cm_sw_r_cso_cp_apan_dp_F5DV40GXDDRN0R72QDWM I used a sheet of plexi glass to make an adapter plate for mounting.