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I have a feedback problem in the subs and I am not sure what is causing it.

the Power is run down the right side and the RCA's down the left they are seperated in the trunk also. The Amp they are running off of is grounded on the bar the runs between the back seat and trunk(the kinda raised area that the trunk floor cover has to curve over). The amp is mounted to the back of the seat there also. The power is run through a splitter that splits it to 3, 8 gauge power wires running other amp's for the front and back mids. The back amp that powers the 6x9s and the Sub amp are attached to the same ground also. Now I only get the feedback in my subs.

What I have tried
Just ground the sub amp alone there. (Still feedback at this point)
RCA's run from back of deck through the cabin so there was no chance of interferance. (Still feedback)
Move all the wires around in my trunk. (Still feedback)

So question now is:
Is it the ground somehow and if I need a new ground where is a good place to ground at?

 
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By Feedback..as in high frequency piercing sound?..describe the sound a little better and I can figure it our easier

 
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no its more of just a constant low with some peaks, its bearly oddible bass feedback in my opinion but you can feel it and hear it, its probably discribed better as interferance, u can hear it when playing music low or off and also the subs pop when u turn the car off

 
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It's picking up some noise from your RCA's.. did you run the RCA's down the drivers side of the car..or the passengers side?..

 
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I did drivers side but yesterday I just hooked new RCA's to test that and it was still there I didn't even run the new ones just pulled out the deck connected them then went strait through the middle of the car to the amp. Also I was doing this with the car off so no fuel pump running and still have the feed back

 
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Sounds pretty odd. are the rca's at any point crossing either the power or ground wires..or running pretty close to them?

 
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I don't think so, only place would be the trunk and I seperated them when we ran the new rcas for the test yesterday and it was still there, I am wondering if it is the ground could that cause it?

 
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the ground could..but it's not very likely..all your grounds however should be no more than about an inch from each other..

 
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my grounds are on the same bolt/screw that I drilled to grouond with and I am wondering if I grounded in a bad place and that is causing it

edit, well other then my ground for the amp under the passanger seat does it matter for that one being on the other side of the car?

 
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Ohh also if it is relavent, I used to have two 10" MTX 4000s and a 300 watt jensen amp with no interferance, then upgraded to the two 10" MTX 4000s and two 300 watt jensen amps, did this using a splitter for the power and Y connecters for the RCA's this was the point that one day the interferance started. Both of the amps were grounded at the same ground that the single one had used for months. Then a couple days ago I upgraded again Went to two 12" Pioneer IMPP's and am running those with a 600 watt Kenwood amp then I also ran more RCA and am running my front 6.5"s off of one of the 300's and the 6x9s off the other one. The two back amps are mounted to the seat and the front amp is under the passanger seat

 
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you have a ground loops.. all 3 grounds have to be in the same location..

 
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THought there was a rule that they had to be within 3 feet of the amp? and the front amp is farther then 3 feet away from the back ground. Think I might have found the problem. When I installed the 2 amps the first time and the feed back started I had switched to some 4 gauge wire the my friends dad gave me and it wasn't car audio wire. it might not be sheilded as well could this be the problem?

 
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Dude.. power wire is power wire.. the only difference for car audio wire is it has a higher strand count and is more flexible.. Also..if the amp with the ground that would be more than 3 feet is for your mids..then it's nothing to worry about..

 
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so u would say get a longer ground wire for the front amp and run it back and ground it with the back ones? seems like that wouldn't matter since the feedback was there before that amp was up there. It was there with just the two amps in the back

 
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try swapping the RCA's and see if that amp still makes feedback noises...or if the feedback switches to the other amps when U change the signals

 
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Try using a ground loop isolator, if that fixes your problem then re-route all your grounds to a solid point. Good luck

 
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what is a ground loop isolator?

 
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It's a Jensen amp.. that's your problem.

 
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a ground loop isolator is simply a transformer. You run it inline with your RCA's. Basically, it electronically ISOLATES the head unit+noise from the amp's inputs. Goto Radio Shack, the ones they sell for 20 bushs are just as good as the expensive ones you'll find at a stereo shop. See what that does for ya.

try hooking up a multipmeter to both ground points. The main ground in your trunk and the other ground you use for the amp under the seat. Use the MIN/MAX function if its on your multimeter and play your music. It will show you the maximum voltage potentioal between your 2 grounds for the given time period. If it's more than 1/2 V, you have serious problems. If its less than 1/2 V, look elsewhere for your problem.

 
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hmm gotta find a multimeter now, ohh and the jensen amps are awsome its the kenwood amp that is giving me problems. So now time to find a multimeter and go buy a ground loop isolator

 
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i had the same interfearence because i was using the stock radio with an amp and subs...because there was nothin to use as the remote wire except for the acc cable in the ignition the amp was always on when the car was on...the only solution is either to retap the cable, add an after market headunit or lower the gains so you dont hear it

 
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Hey BlueBullet, thats not a ground loop isoloator, you are talking about a line-level converter. Change your speaker wires into RCA's for your amp, right?