Soundtube RS400i-BK - Two-Way 4-Inch Hanging Loudspeaker (Black)The RS400i is a 4, two way ported speaker with an open ceiling enclosure design that delivers effective low end response (76 Hz) and 125 off axis performance (2 to 10 kHz, independently verified). SoundTubes proprietary BroadBeam waveguide tweeter system delivers consistent high performance audio across the operating bandwidth. The RS400i speaker design incorporates a low profile grille and a five position tap switch with transformer bypass position.