I just noticed this weekend that it seems like there is a bad ground connection somewhere with my amped rear 6x9's. You know the whine that changes pitch when you press the gas. It just started happening this weekend, nothing has been changed and the system has been working fine until now. I have noticed that it has started to get worst over time as well. I have checked all the connections on the amp, car, and speakers. Everything is nice and tight. Could my amp possibly have a bad internal connection? What else might be causing the problem?

 

ya i have the same problem anyone got any ideas?? its bad and really annoying

 

what HU do you guys have? wheres the ground connected? any other amps?

 

im going to have to agree deffinetly a bad ground somewhere what are you grounded to?

 

I have the kenwood DDX-512. The ground for both amps is attached to the rear seat mount. I tried swapping rca cables too and had no luck. From doing that it seems like the majority of the noise if being caused when I plug in the left input. I have another amp for my subs that are working just fine and uses the same positive and ground connection points.

 

the amp might be sensitive... rear seat mount is a very bad ground location as ive said here a few times. buy some longer wire and go straight to the battery

 

If I move the ground cable and I still doesnt resolve the issue would you think its the amp?

 

mine is doing the same thing, mine started when i hooked up the front channels. i got mine grounded to the battery

 

It's called engine noise... Check and make sure your RCA's are not near the power cable, and wiggle the ends of the rcas, and if it stops when you do that, you inturn have a bad rca

 

x2 RCAs being near a power cable will make that whine. I know mine did for a while. But only when it was by the high current draw lines. I bought better shielded lines and reran the RCAs and its all fixed.

 

could be the amp, could be the rcas, theres alot of issues it could be so id go at it one step at a time. if moving the ground doesnt fix it then an rca swap may be in order. aslo they shoudl run down the pass side of the car

 

I have not had time to relocate the ground cable yet but as far as the RCA wires go this is what I have done. I plugged in a different set that is ran to my other amp that doesn't have the engine noise going threw the speakers and when plugged into the 6x9 amp the engine noise was still there. The RCA cable from the radio is ran down the middle or the car and my sub amp. From there the output of the sub amp is ran to the input of my 6x9 amp. I have moved the cables away from any power and tried wiggling the cables and the noise never goes away.

 

ok im going to get some new high quality rca cables, i noticed when i move mine around in the trunk that the engine noise varies depending on where the cable is. closer to the speaker wires more noise, also seems like the rca cables are interfering with each other. im going to re-route my current cheap cables for now till i get new ones ordered. im looking at the moster cables.

anyone have suggestions on what rca cables are good and shielded?

are these any good? these are 4 channel rca wires
Monster Cable MicroXLN 4C4M 4 CH 13 FT Interconnect

KICKER 09 XI44 4M/METER 4 CHANNEL/4CH SIGNAL CABLE RCA

Stinger 4 Channel Helix 12' RCA Cable Interconnects SHX

ya there are a lot of options when it comes to buying rca cables.

 

when you disconnect the RCAs from the amp does the noise go away?

 

Yes the noise goes away but when reconnecting any RCA it comes back. But then again disconnecting them means there is no signal getting to them. This wouldn't eliminate the possibility of a bad ground would it?

 

It doesnt eliminate it, but it does tell you its something to do with the RCA cables or head unit, try disconnecting the RCA cables from the head unit, if that gets rid of it, try touching the outer shielding on the RCA plug to the place it connects on the head unit. My guess is you have one of the following problems

1. bad RCA cables (get new ones)
2. a power wire running next to the RCA cable (rerun either the power wire or the RCA)
3. bad ground on the head unit (dont remember how to fix this exactly, but you could run a grounding strap to the casing and that should fix it)

 

^^^ kenwood doesnt really have the grounding issue like pioneers unless there was an issue with the car ground somewhere along the line but the chassis to rca ground wont do anything for a kenwood

 

I had some free time today and figured I would attempt to resolve the interference issue. I have tried the following things and nothing seems to be working:

My setup is this:
RCA from the back of the headunit to input on Amp for Subs
RCA from output of Sub Amp to Rear Speaker Amp with highpass filter on

Things I tried
1) grounded the amps to the battery (no change)
2) swapped out rear speaker amp with one I had lying around (interference was worst)
3) Took RCA from input for the subs amp and used it as a direct input for the rear speaker amp (no change)
4) Used RCA cable that was used to jump from sub amp to rear speaker amp and put it in the back of the radio then to rear speaker amp (no change)
5) checked all wiring on the headunit
6) Connected rear speakers back into stock wiring (interference gone)

Where does this leave me at now?

 

Try a different headunit.

Looks like you may have ruled out everything else.

Or a ground loop isolator. I know in most cases they don't help but
in your case it might be worth a shot.

 

this whine u talk about. i had it for awhile. i have the brains for the headunit under the passenger seat and when people got in the back they didnt care to look where their feet were going so the connection terminals for the subs were broken. to fix this for the time being i had to put pressure on the cables upwards to make the connection inside the box. after awhile i got it warrentied and never heard it since. after the reinstall it came back but the cause of it this time was a poorly fastened ground wire. every bump i hit either stopped the high pitched whining or came back.

 

I dont think its the headunit or it would make the noise when connected to the stock wiring. I may just buy better RCA cable from somewhere and see if its actually bad. Its the only thing that kind of makes sense to me at this time. Or possibly get a filter or isolater

 

Oh, I forgot that you were running only the rears off the amp.

I would say that you have eliminated the amp (you said that the other one was worse)
Unless they are both bad. Not likely, but possible.

Speakers don't develop whine unless they have dc current going to them, either through the speaker leads or the mounting surface.

For ***** and giggles, hook up a speaker that isn't mounted to the car to the speaker outputs from the amp to see if it still whines, and hold the speaker in your hands when you do it.

I've seen if a car has a wire grounding out somewhere that isn't supplying alot of voltage (EG-5v leads) make speakers whine if the power can get to the frame.

But trying different RCA's is a more likely solution.

 

Check grounds in the engine bay.

 

Do you know where they are located?

 

thats stupid a ground in the engine bay isnt going to do anything. trust me man run a new set of rcas down the passenger side and make sure nothing else is ran there. also re ground your HU to the amp in the back. cap off the ground in the harness