... : 3"bass+trebleFrequency Response: 40Hz-18kHzDescription1.Built-in USB and SD memory card function2.Support MP3 Music format3.Volume,bass,treble ... speaker,5.1 multimedia speaker.2.We can add USB/SD function and FM function on multimedia speaker,Mp3 speaker,speaker ... the way.5.We can make professional speaker,mini speaker,SD card speaker,hifi speaker,USB speaker,5.1 multimedia speaker ...