Hello, (long time listening & learning) Looking for some help/advice. Have just had installed PXA-H800 Alpine Sound Processor + RUX-C800 Controller PAD 5000.5 Polk Audio 5 Channel D Class Amp DB 6501 & DB 651 Polk Audio Speakers MM840DVC Polk Audio 8" Sub Stinger 9ft Pro3 2CH RCA TDJ Audio Level Converter Stinger Gold SE 60Amp Fuse & Fuse Holder Using Factory Head Unit The sound quality (ignoring the issues) is a huge improvement over Factory Premium sound My issues are: Constant hiss (Volume does not vary) sounds like the recordings from tape in the quiet periods. (for those who may remember) This is always there sound down to zero included, put it into reverse (No audio) hiss still there. Next is the reverse sensors have been amplified, deafening if volume of stereo is left up. When the phone rings it no longer sounds through the speakers but the number displays on the screen. I have searched through a lot of other posts and found a few similar regarding the hiss, but according to my receipt it has a LLC fitted. Does anyone have any solutions, thoughts or advice to rectify? What may they have done but should or shouldn't have done? Thanks Any help is very much appreciated