speaker hissing help

[randomtask37]

So I finally got an opportunity to complete my stereo install and turned it on tonight. I followed the $500 killer stereo sticky thread (http://www.r3vlimited.com/board/showthread.php?t=231107) if your wondering how i wired things.

All 4 speakers are sub are working however there is a hiss as soon as power hits the amp. when i turn the car to the 'on' position (engine running and engine not running) and the headunit kicks on, the hissing starts. This happens on any input with music playing or not.

For example: At volume 0 the hissing is audible. at volume 35 hissing turns into a higher pitch ...whine... or squeal... not sure how to describe it -- this is with the headunit input set to auxiliary and no music is playing, nor is a wire hooked into aux jack. its a steady noise.

I tried disconnecting the rca's from the amp hoping this would stop the noise and i could pinpoint the problem to the front of the car, but this didnt stop the noise.

one other bit of information... i dont have the stock power antenna installed in the rear. but it is hooked up at the head unit.

Does anyone have any advice to stop the hissing?
this is sad for me after all the work i put into getting everything hooked up.

Some background on my setup

Kenwood Excelon KDC-X496
Planet Audio 1800.5
infinity reference 1262W

pics of the trunk

amp wired up


amp ground (before power hooked up)


the aftermarket speakers which were there from the PO

[Gregs///M]

Since you disconnect the input RCA and the hiss was still there, it is safe to assume the problem lies inside the amp or at one of the speakers.

Disconnect all speakers and hook up one at a time with the amp on. If one speakers causes the hiss, there is a short there.

Alternately, you can measure the impedance of each speaker network with a multi meter. They should be 4 ohms. However, I find it easier and better to just hook up one at time. Some speakers might not short until they actually start moving.

I would start there.

[dwvw]

How did you set your gains? Just crank them up?

[randomtask37]

Thanks for the advice greg. Ill check for shorting. If it makes a difference, the hissing is coming through all 4 speakers at once and it seems to be the same sound coming evenly from all the speakers. when i control the fader/balance at the headunit and silence all but once speaker at a time, the sound is the same from each.

When the amp gain is 1/3-1/2 the hissing is quite audible. Its certainly noticeable when no audio is playing, and can be heard over music at lower volume levels. When playing music at higher volumes its not quite as noticeable until a song has a quiet section. Right now i have the amp gain set to 1/4 so the hissing isn't so annoying, but the speakers can handle more power. and im pretty picky and want the background to be silence ... or at least damn near silence when the gains are set high enough to max my speakers. (not overkill but just right at the max)

[agent]

I have that same amp and virtually zero hiss, so FWIW I'll try to get a picture of the crossover and gain knobs on mine for you.