Sound deck apt x encoding bluetooth 40 voice function crossover frequency 170 3000 hz woofer 2 x 100 mm midrange 2 x 50 mm tweeter 2 x 19 mm bass and treble control virtual surround sound stereo playback semi gloss finish speaker system 21 components subwoofer transmission mode wireless wireless transmission bluetooth bluetooth version bluetooth v30 analogue input audio input digital inputs digital audio input coaxial digital input optical