Active Stereo Loudspeakers Set 2x30W 4 Ohm, RS-232, whiteThe APart SDQ5Pir powered loudspeaker set is a versatile and very compact, easy to use sound system. One unit contains a stereo amplifier loudspeaker with a 5.25” woofer, a HF unit. One output is fed to a second linkable passive loudspeaker.S..