... "(woofer)+(3+1.5")*2 [ tweeter] *Built-in USB and SD memory card & FM function, 2.1 active home theatre speaker(SP-2201 ... :≥65DB8.Distortion factor:≤10% Description:1. Built-in USB and SD memory card & FM function,Support MP3 music format2. volume, bass, treble separately ... ³):1660sets,415ctns 2.1 speaker Home Built-in USB and SD memory card & FM function,Support MP3 music format