detachable, fold-down face 3-color display with green button illumination plays CDs, CD-Rs, and CD-RWs plays MP3 and Windows Media (WMA) files displays MP3 text CD Text 0-bit mute (mutes output when no audio signal is detected) MaxTune SQ tuner 12 FM6 AM presets station title memory Bass Engine Plus (bass center frequency, width, and level, plus treble center frequency and level adjustments, as well as 4-channel digital time alignment and a 3-position, 12dBoctave crossover) Media Xpander XM Satellite Radio controls (XM Radio subscription, tuner, antenna required to receive the satellite radio signal.)- service not available in Alaska or Hawaii CD changer controls for Alpine Ai-NET changers only optional auxiliary input MOSFET internal amp 4-volt front, rear, and subwoofer preamp outputs wireless remote clock 23 watts RMS50 peak x 4 channels CD frequency response 5-20. 000 Hz CD signal-to-noise ratio 105 dB FM sensitivity 9.