The MusicCast sub 100 is designed for use with a MusicCast surround-capable AV receiver for a 5. 1-Channel home theater system or with MusicCast stereo/surround-capable wireless speakers for a 2. 1-Channel stereo system. It brings your movies, TV and music to life with rich, powerful bass that you can feel. The 8? woofer unit and twisted flare port create clear and tight bass. Its piano-black finish fits with any decor. Control your MusicCast system with the MusicCast app and Voice control with Alexa.