turn off internal amp, run external amp. If it doesnt work then you need to send it in for repair VIA clarion's instructions. Totally useless feature that causes way more trouble then it can help.
Every head unit has a weak internal amp. Thats how your speakers play music bud....
Its in the audio or system options.... Play around or check the manual. If you cant find that, definitely dont get an 80prs lol. You. Will get lost and wont find anything.