Review on Zamkol ZK306 Waterproof Bluetooth Speaker with 30W Stereo Sound - Portable, Wireless, EQ Bass, 5200mAh Battery, Mic, TWS, Bluetooth 5.0 - Perfect for Outdoor Use, Great Gift Idea by Shane Miller

Bought for use on tennis courts. Being used on outdoor tennis courts I wanted this speaker to be loud and have good bass. Luckily it has good and tight bass (possibly due to the dual passive bass cones), and surprisingly the mids and highs were clear and pleasant too. Good thing and I just hope it lasts 5 to 8 hours at around 70% volume. I would be happy about that. I could have given 5 stars but decided to give 4 because this is not a 30 watt speaker. I compared with Oontz Ultra (14W) and Earfun speakers (24W). It's a little behind the Earfun but has better bass and a warmer tone to compensate. I'd say it's an 18-20 watt speaker, which I agree with.