Powerful Bass Bluetooth Speakers】——【double Bass and double tweeters】A21 Bluetooth Speaker is a portable Bluetooth speaker, it have 4 loudspeakers including double Bass, double tweeters and a rear heavy bass guide tube. With this speaker, you’ll feel as if you’re at a live concert, with clear high notes, deep bass and true HD sound.60W Big power blueooth speaker can provide very powerful stereo and amazing bass sound. It will bring you an unprecedented listening experience.