Okay well first off i just bought a new head unit, its a jvc kd r600. I had replaced the jvc with a new jcv which is the kd r600 bc i thought that was the problem. I had got an amp from my buddy its a 580 dual amp 2 channel, I already had the sub. Its a sony xplod 800 watt 4 ohm, well after going to get all the wires and everything i then installed everything and after it pounded for a 10. When i first installed it my old jvc head unit was still in the car. It worked fine for about a month i would say, then i disconnected the amp and the sub because i had to put a lot of stuff in my trunk. After that day its never been right and for the last month i have been trying everything i know to get it back to working but nothings changed. When i hooked everything back up it worked but didn't hit hard at all, so i thought i maybe hooked a wire up wrong, but nothing was wrong ground was fine, rcas were fine, power was getting 12 v constant and remote was hooked up fine on head unit and amp. After looking at everything and not finding anything i said whatever. Well i let it go for about a week then i looked at everything again and i couldn't find anything!! it only got worse from there it went from not hitting hard to cutting in and out, to it cutting out my speakers. SO after everything i said fu** it and went and bought a brand new 115$ jvc head unit. After installing everything i hooked the remote up etc. The **** thing is still doing it!! I have tried 2 other amps and 2 other subs and its doing the same thing. Im ready to just sell them but i don't want to. I am completely out of ideas... Please HELP
this is where you use the DMM to measure AC output from the amp with the sub disconnected - while playing test tones on the head unit. that will verify if the amp outputs are functioning.
most modern head units have a sub level control that is factory default is off or low. turning that on and increasing sub level is sometimes required. the r600 is selectable rear or sub. and when set to sub has adjustable sub level control.