Bluetooth Subwoofer Amplifier 2.1, BT30D Pro Subwoofer Amp with TPA3255 Chips 165W x2+350W & Bass Treble Control, 2.1 Channel Sub Amplifier for Desktop/Outdoor/Bookshelf Speakers

This amp is perfect for my listening habits. Plenty of power, nice clean signals, interfaces easily to my powered subwoofer. Plenty loud! Its footprint is so tiny, its amazing the sound it produces. And the price is less than $100. Would be great for a desktop sound system. Bluetooth is super easy and very strong. The unit cannot be controlled with a dedicated remote, which is sort of a downer, but if you're using Bluetooth predominantly -like me, your phone controls the sound, so no problem. You must supply your own cable for the subwoofer connection and for the speakers. Setup was a snap! If you have a small room for listening, this product will please you with a big sound for a small price.

This amplifier is outstanding. I originally bought the Klipsch ProMedia 2.1 system, but the amplifier was dead on arrival. Instead of replacing the entire speaker system again, I bought this Fosi Audio amp for roughly the same price—and it completely transformed my setup. I hooked it up to my existing subwoofer and speakers, and the sound quality is phenomenal. Clean, powerful, and punchy bass with excellent control. If you have a speaker system with a failed or weak built-in amplifier, this is an excellent solution. It brought my system back to life. I went with the upgraded version (the higher-power 165W model), and I highly recommend it even if you’re running smaller speakers. The extra headroom makes a real difference in clarity and dynamics without distortion. I’m using it with my computer, and the Bluetooth feature is a huge bonus. I can stream music directly from any device with zero hassle. Rock-solid connection and great sound over Bluetooth as well. I honestly don’t know why I waited so long to buy this. If you’re on the fence, don’t be. This amp punches way above its price.

So for people reading this thinking why the glowing review, let me tell you first what my main system is. My speakers are B&W Nautilus 804’s with Nautilus 800 HTM 1 center, 805 surrounds and SVS height speakers for Dolby Atmos powered by a Denon AVR-X4700H. This amp and speakers in no way compares nor could it. For my computer, I bought a Cambridge Soundworks package containing The BassCube 821 and the MC 105 speakers about 13+ years ago. The BassCube has a down firing 6.5” polypropylene woofer (4 ohm) in a sealed box that also contained the amplifier for the three speaker system. The MC 105 (8 ohm) has a 1” aluminum dome tweeter with a 3” midrange in a sealed cabinet. The system was similar in design and appearance to the Klipsch ProMedia 2.1. Unfortunately, my system finally failed after years of service leaving me searching for a suitable replacement for that particular location and purpose. What failed was the amplifier that powered all 3 speakers. The power supply filter caps failed taking out components down line – not worth fixing. I considered the Klipsch ProMedia 2.1 but the long wait time and some reviews mentioning early failures and sound issues made me hesitant. My next choice was the Edifier S350DB which is larger than the Klipsch and my Cambridge system and it too had it’s detractors and is $400. So, I tried the Fosi Audio Bluetooth Subwoofer Amplifier 2.1, BT30D Pro and was blown away by the sound. Connecting it to the MC 105’s was easy as I just needed good speaker cable with with banana plugs at one end for the amp and twisted wire for the speakers. The 6.5” subwoofer speaker I connected internally directly to the existing speaker terminals. I first removed the wires from the internal amp and used two of the four speaker terminals on the back to connect the woofer to the sub input on the Fosi. Then I put all the screws back into the back panel of the subwoofer to close it making a good air tight seal. Previously, the bass coming from the BassCube 821 when it worked was boomy at times and sloppy it wasn’t tight and certainly didn’t go deep. Now it feels tightly controlled, musical and it goes way deeper. It seems to have more synergy with the MC 105’s which also sound more musical to the point that I actually listen to music while working on the computer instead of watching TV. Your mileage may vary based on the speakers you use but at this price point for me at least it was worth the try and I am amazed/surprised at the audible results. The amp has just the right settings to tailor the sound to your speakers and preference. The separate Bass and Treble are mainly for the smaller speakers and have little effect on the subwoofer. For the sub you have SUB FREQ which sets the cutoff point from deep bass going clockwise on up and SUB VOL which together give the ability to tailor the sound to your liking. I bought a power strip that turns on the monitor and the amp when the computer powers up so I don’t have switch it on and off, the TrickleStar TS1104 7 Outlet APS, 1080 Joules, 3 ft Cord White sold on Amazon https://www.amazon.com/TrickleStar-TS1104-Outlet-1080-Joules/dp/B0B61ZCPK6. Now when I turn on the computer everything turns on by itself, the amp and the monitor. So if you have a dead Cambridge or Klipsch system and are handy with a soldering iron or if you have speakers you really like but their current amplification is not so great, give these a try, you might be pleasantly surprised. BTW, I have received nothing in return for this review. All the best: Art If you found the review helpful, give me a thumbs up - Thanks!

EXTENSIVE testing trying to figure out "why" this great little amplifier didn't punch out the power. The subwoofer amp kept clicking off at higher volumes with the stock AC/DC 32v adapter. I ended up using a 12/24v to 36v step up booster and a 24v (10a) AC/DC adapter (Output is 36v, 10-amps). I tested the max current draw at full power - about 8.6 amps! The stock adapter is rated for 5 amps. Duh? That was the problem. This amp runs at 36v all day long...and a little warm. But, if you want full power and not having the subwoofer amplifier chip kicking off all the time -- either get a 32v (10-amp) adapter or even better 36v (10-amp) adapter. The good thing, a simple turn off/turn on resets the amp (subwoofer amp will reset). The Bluetooth 5.0 is phenomenal...excellent and fast connectivity. The fidelity and sound quality is totally quiet and pure. THD ratings are probably dead on accurate. It really plays beautifully all the way up to full power. The pre-amp out 3.5mm jack is a brilliant addition -- I tested it and it works like vintage equipment. Bluetooth connectivity is not affected. Linear with mains. If you ever wanted to add an active sub via this jack, you can -- it is full range. AUX input works -- no issues with low power pre-amp section like many other of these little digital chip amps. Bluetooth 5.0 is set HIGHER than expected -- NICE job Fosi! So many are set too low. Use banana connectors for your speaker wiring -- 4-8 ohm for mains, 4-ohms plays best. BOTTOM LINE - feed this little guy 36v and 10-amps of power and it is one helluva performer. It will deliver some nice subwoofer bass if your subs are decently efficient. PA sub cabs @ 4-ohms work best. Car subs are not that efficient (low SPL per watt). For those just wanting a lower volume 2.1 home AV system (like for watching TV or on a computer), no need to upgrade the included AC/DC adapter. For me, why by a Corvette and drive it like grocery getter Camry?

I’ve been using the Fosi Bluetooth Amplifier BT30D Pro 2.1 for several months in my garage, and it has completely transformed my music experience there. I run it with a pair of Polk Atrium5 speakers and a small 8” subwoofer, and it delivers impressive sound quality that fills the space beautifully. Compared to the previous version I owned, this one definitely provides more low-end impact, which was the main reason I upgraded. The bass is fuller, punchier, and makes listening to music while working in the garage much more enjoyable. The amplifier itself is compact, solidly built, and easy to integrate into my setup. The controls are straightforward, and I like that it allows separate adjustments for the subwoofer channel. That said, I’ve noticed that if I push the volume to the maximum, the subwoofer channel sometimes drops out and requires a quick reset. It’s a minor inconvenience, but it only happens at extreme volumes and is easy to fix. Bluetooth performance is solid, with clear, stable audio. My only small gripe is that the unit doesn’t automatically connect to a previously paired device. However, reconnecting takes only a few seconds, so it’s a very minor annoyance compared to the overall performance. The sound quality is excellent. The Polk Atrium5 speakers are crisp and detailed, and the 8” subwoofer adds the perfect punch to bring music to life. The overall balance between highs, mids, and bass is impressive, and the amplifier maintains clarity even at louder volumes. It’s made my garage feel like a proper personal music space, whether I’m working on projects, tinkering, or just relaxing. In summary, the BT30D Pro 2.1 is a fantastic choice for anyone looking to power a 2.1 system, especially if you want more bass and clean, full sound in a compact unit. The occasional subwoofer reset and manual Bluetooth connection are minor drawbacks, but they are far outweighed by the amplifier’s performance. I’m extremely happy with this purchase, and it has made my garage music setup much more enjoyable over the past few months.

I am very happy with this purchase, to the point where the product deserves a review! Build quality and appearance are excellent, sound is very good, and the price is right. NOTE: you NEED BANANA PLUGS. The little plastic screw tightener on the speaker lug strips, at least if you try to tighten it enough to have a decent connection of any kind. They're pretty but not very functional. NOTE2: get short, insulated banana plugs, the kind with a non-metal outer shaft, because they otherwise might tilt and touch each other. (see picture) The TPA3255 chip does *not* have short circuit protection, so you need to be extra careful! [edit] You want banana plugs with an insulating shell, heat shrink tubing, or just some electrical tape. See picture. The amazon basics and FosPower Deadbolt plugs are large enough to be almost touching, and although the shells are anodized, they're still metal. Anyway, you have been warned; just don't short out the connections! :) Application: I am using it with a pawn shop sub and a pair of old Radio Shack Optimus diecast aluminum speakers (the last descendant of the old Minimus speakers, basically they sound great but have zero bass). The sub is 4 ohms and supposedly handles 200W RMS (dual-6" speakers, really?) and the Optimus speakers nicely handle 50W RMS (8 ohms) but only if it's all midrange and treble. It's a bedroom stereo, so it's primary goal is to sound good quiet, but I do sometimes need to wake up. And I like bass. :D I bought the bundle with the 48v5A power supply, which because I have 8 ohm speakers and like to play music loud sometimes. :D Math suggests that ideally (and nothing is ideal), the power supply can deliver 240W to the whole system, and have enough voltage to drive the (4 ohm) subs to no more than 140W and the (8 ohm) tops to about 70W (RMS). In practice it seems to deliver. It's basically a perfect match for the 50W tops, while the sub surprisingly handles all of the supplied power until the amp runs out of headroom. (The sub channel distorts gracefully.) I have not attached a scope to see what the *actual* power output is, but AFAICT power is limited by the power supply voltage and speakers, not the amp itself, which is consistent with modern digital power amps. The whole system sounds good: as good as those speakers have ever sounded. :) The treble and bass controls are unintrusive, neutral at center-ish settings, and work. I wish the treble had a little more boost and cut, but I'll take "unintrusive" over "more boost" any day. The subwoofer has plenty of gain, and the frequency control has a smooth rolloff-- I used it to tame the peak at the top of the sub's frequency range a little. The system distorts gracefully when pushed. I primarily use bluetooth. This and the old technology of the speakers appears to be the only limiting factors for tone. A good system, would buy again.

Fosi implements the TPA3255 chip very well again in this model. I think it sounds as good as my Fosi T20X MKII amp, but with the built-in sub amp (also a 3255 chip). This amp is a dream for those seeking big sound from a small footprint. I use mine in the bedroom with small speakers and a passive subwoofer. I'd recommend possibly forgoing the supplied power supply and go for 48 volts with at least 5 amps if your speakers are a little hard to drive. The supplied 32v 5A PS is fine for me, but I do wonder if having a pair of TPA3255 inside would benefit from more dc reserves. It's a good buy when considering that it's two amps in one, the power supply is good, and the TPA3255 is a really nice performing platform. Your picky spouse won't hate it. EDIT: I got a 48v 5A power supply and it does help if you need an extra power bump. I imagine a 10 amp PS would make head bangers even happier, but I'm done.

This amp has been a disappointment. I purchased it for a computer desktop subwoofer/satellite speaker system which is what it is marketed for. However, I have found it impossible achieve that. The amp sends the full bandwidth to the satellite speakers which never have extended low frequency capabilities. The result is that I can only get a few watts of power to them before the state to distort badly due to excessive cone motion below the ported frequency. There is another oddity in the design which was posted on the Audio Science review website. It shows a additional gain in the 50hz-80hz region that was achieved with a filter internal to the amp. This is the "fun" region that makes speakers seem punchier and bassier that they really are. It is a sacrilege in design of an amplifier to intentionally manipulate the frequency response this way; amplifiers should have flat frequency response. It makes it nearly impossible to achieve good subwoofer/satellite integration if you are doing your own equalization. The controls and features needed to make good use of this amp are missing. Things like a high pass filter for the main speakers and a marked crossover frequency for the subwoofer along with low pass filter for the sub so it is not trying to play frequencies out of its range. Overall, what's there is well made, sounds clean on extended range speakers (large ones), but is missing features that make is usable as a 2.1 amplifier.