... 4.Speaker unit:4"+3"*2 2.1 speaker, computer speaker, multimedia speaker, iphone speaker, USB speaker, MP3 speaker, mini speaker, speaker, home theatre speaker,portable speaker,bluetooth speaker, vibration speaker, speaker box, speaker system, subwoofer speaker,karaoker speaker.2.1 Theatre Speaker ... : 40Hz—200Hz Frequency: 150Hz—20KHzunit: 4"/4Ωunit: 2.5"/4ΩS/N: ≥45 dB S/N: ≥68 dBDimension: ...