50W+50W+100W 2.1 Channel Subwoofer Amplifier Board with Treble and Bass Control, Dual TPA3116 Chip, DC 12-24V, Bluetooth and AUX Inputs, DIY Wireless Speakers AMP Board, Password Free (ZK-TB21)

I was using a vintage Pioneer 25W/ch receiver for the sound system in the workshop. I also have an old JBL powered subwoofer that had the amp go out, so I decided to order this little amp to see if I could power the old sub with it and at the same time replace the old Pioneer receiver for a little more volume, in addition to the sub added.The final setup: Two existing ceiling speakers, 8 Ohms each, paralleled with two Klipsch bookshelf speakers, 8 Ohms each , for a net 4 Ohms per channel; re-purposed JBL sub that has two 5 Ohm speakers in parallel, so 2.5 Ohms total. Amp is powered by a 24V/100W LED driver.The result: awesome! The bass could be better, but considering that the subs are only 6” diameter, not bad, certainly much better than without the sub. The Klipsch bookshelf speakers add a lot to the midrange and highs, complementing the ceiling speakers.As for the power supply, I first hooked it up with a 24V 60W power supply, and it worked fine, although the subwoofer started to clip at a fairly low volume. The power supply never got warm however. I tried a 24V/100W power supply anyway, and the bass was vastly improved. This tells me that the 60W was not able to supply the current peaks, so the 100W is staying. So, spend a little more and go for the bigger power supply to get more distortion-free bass.What I like about this amp: BT works flawlessly, connecting each time without fail. The range could be better, but understandable since the built in antenna is just a small PCB trace. There is a connector for an external BT antenna if desired. I like the audio controls: Bass frequency cutoff and volume, treble/bass/volume for the stereo channels. The amp is very power efficient, and has more power available than what I need. With a 24V power supply, driving 4 Ohms per channel + 2.5 Ohms subwoofer, it barely gets warm after several hours.My only complaint: The speaker terminals are tiny, so stacking wires greater than 2x 18ga can be difficult.Bottom line: highly recommended.

I have been looking at these inexpensive little amps for a few years and never really had a use for one, as I have a pile of older amps around the house for my systems. I have been upgrading my home office and decided it was time to bring some solid music playing into the office, as I do my best work with LOUD music ;-). had a pair of Polk bookshelf speakers that had been sitting in their original box for a few years from when I picked them up on sale from Frys. wanted a small amp to drive these off my PC, Alexa, and TV, and I liked the idea of how small this amp was and could mount it under my desk. had concerns about such a small amp pushing 8-ohm speakers as most folks were using it with 4-ohm set-ups. If I got I could return it it and did not like the sound/power, I could e you do need to do some assembly, and I recommend some felt feet if you plan to put this on a surface. Assembly was easy, and I quickly wired up the Polks. At first, they sounded like crap, but then I started to play with the tone and slowly dialed them in. The Sound got better as time went on. Like most amps/speakers, I find they need a little time to warm up, and the sound gets richer. With just the polls, I got pretty good sound and loud enough to annoy my wife. But, the amp would distort at the highest output. The Polks do not have a very low range, so the base was lacking. This is where I made a mistake when choosing this amp. It has a powered output for the sub amp, so you need a passive sub, and most home subs on the market today are powered. I did not want to spend a fortune on a sub, so I looked into making one and came up with a cost of about $50-80, depending on what drivers I chose. Then it occurred to me that a lot of the 'home media' speaker set-ups come with a passive sub, so off I went to eBay. I bought a refurbed SONY passive sub for $30 delivered on eBay. I got it and hooked it up, and immediately, the package was complete. With the sub hooked up, this amp has plenty of power to drive all 3 speakers and get very loud without any distortion. Still dialing it in some more, but it just gets better. If you want a cheap little set-up that you don't need 'high-end' sound, this is the amp for you. I think I will pick up a few more to drive my outdoor speakers this summer because I can hide the amp just about anywhere and very little heat. I did have to buy a power cord for a few bucks, but you can use an old laptop cord if you have one.