Had a clarion nx501 installed and I am disappointed in sound quality and in fact their isn't much sound coming out of my rear speakers, but I love everything else about the head unit. Volume only goes to 40 and seems to be about the same quality as stock other than the issue with rear speakers. I have owned about 5-6 diff aftermarket radios in my other vehicles and sound quality has always gone up, but volume also went higher up than 40. To me it seems their is something wrong, but I am not sure. Anyone else have this head unit installed? I have searched google and I am guessing the unit is to new for any issues I seem to be having, Any suggestions? If I can't seem to fix this issue I am going to have to go with something else, any suggestions on nav units?