inputs.text: easy install great sound - purchased alpine cde124sxm alpine ktp 445 power pack amp amazon 20400 10400 respectively im alpine fan replacing ten year old alpine head unit one considered buying kenwood deciding id rather satellite radio hd radio jacksonville fl doesnt many hd stations available time head unit amp truly plug play installed hour chevy silverado ext cab pu not run satellite antenna yet not using satellite tuner time installed radio sounded great infinity reference series 2way 6 12\\ speakers front doors 4\\ x 6\\ 2way plate speakers rear doors hear difference tried connecting head unit sound clean clear radio alone couldnt really push speakers produce much lower frequencies fill sound radio rated 45w x 4 good day likely closer 10w x 4 range adding ktp 445 power pack really made huge difference full range sound highs clearer mid tones present produced much bass door speakers capable handling head unit full range sound shaping adjustments really help tuning system enhance strengths hide weaknesses quickly access treble mid range bass level adjustments drilling little deeper system allows set adjust crossover points highs lows also separate adjustments sub woofer crossover points level controls ive decided add sub within next weeks primarily listen ipod head units controls connecting usb plug front head unit model not come ipod cable use one came ipod allows quickly search playlist search collection music artist song genre lets search music listening songall alpine cde124sxm ktp 445 perform way would expect alpine perform not model use looking build large complex booming system one set pre amp outputs sub woofer believe rated 2volts instead 4volts lacks high end features like channel delay surround sound features may find expensive cda models however offer enough big sound make forget guy front whos talking cell phone driving slowof playlist search collection music artist song genre lets search music listening song alpine cde124sxm ktp 445 perform way would expect alpine perform not model use looking build large complex booming system one set pre amp outputs sub woofer believe rated 2volts instead 4volts lacks high end features like channel delay surround sound features may find expensive cda models however offer enough big sound make forget guy front whos talking cell phone driving slow