Stereo engine feedback (buzzing in speakers)

I did a search and didn't find what I was looking for so here goes.

Stereo installed with a used amp I got from my bro. Sounds fine with engine off but with the engine running I get major feedback. Seems coordinated w/ rpms. Both my positive and negative lines are hooked directly to the battery. Stereo is hooked up to boat systems.

So how do I prevent the feedback?

Make sure you have sealed RCA cables and make your Power and ground wires as short as possible. Keep you power wires away from your RCA's .

There may be other problems but those are the easy ones to check first.

What E Double U said. Have your RCA's coming from one side. Power from the other.

If you do everything you can, to separate them, and you still get feedback, try an inline noise reducer. These help a lot.

Ok, went out to the boat to check it out, RCA cables are definately separate from the power lines. Even with out the boat running it makes a loud buzzing with volume completely down, when running its unbearable. The amp does not buzz if the RCA cables are removed. So, does this mean that my player is bad or that the amp is bad?

Power and ground lines are both fairly long as the battery is in the back of the boat but I never had this problem with the previous amp.

If you can, hook up a couple of speakers directly to your deck. If the problem is goes away then your deck or Amp outputs might be bad.
I had the same problem recently with my system and the Deck's rca outputs were bad. It will play hooked up with out and amp perfectly but when it is hooked up to the amps all of the static and engine noise comes.

You probably need a new Deck.

you most likely have a ground loop, you can get a ground loop isolator and try that, they usually work if you don't use them on your sub amp, also back off on your gain, it's very common to get engine noise when the input level on your amp is to high

Shane, whats a ground loop? /isolator? I already adjusted the gain and the noise was constant no matter what the level.

this just happened to my amp in my car for my subs a couple of weeks ago. i brought the car to the stereo shop and they fixed it in like 2 minutes. unfortunately im not sure what they did but everything looked the same when i got the car back

a ground loop isolator plugs into the RCA inputs on the amp and filters out the noise, it's a quick and easy fix. How do you have your amps grounded? You could try running a wire from the ground on your head unit to the ground on your amp and that can fix the problem too.

Shane, I'll try that next time I'm in the boat, that's a quick one. Would radio shack have an isolator or am I better off going to circuit city? Also how much do those run?

I only have one 4 channel amp. Because it is so far from the battery I went to home depot and bought some real thick industrial cables that are connected directly to the battery. Because I have those up there I have tied into them for other things as well like my ballast pump and spotlights. So far that has not been an issue.
My stereo is not the prettiest, infact I put a couple pics in the redneck stereo post but it should sound good if I can get this figured out.

As long as I'm talking. I was down on Lake Mead on Friday. Water was beautiful but fricken freezing. Spring is short here in Vegas but man, I coulda used a full suit instead of my old spring suit.

Circuit City should have them, it shouldn't be any more than $20

just eliminate the ground loop. you would need to ground your HU to the battery that your amp is hooked up too. Or by a line driver....by increasing the voltage thru your RCA's you should eliminate noise as well.

Ground loop isolators are on e-bay for $.99 then about $10 shipping. I'll run a ground line from the back of the stereo to the amp ground next time I'm there, should take about 30 seconds. If that doesn't do it I'll try the isolator.

I had the same problem in the past. I just ran a separate ground wire from the back of the deck(there should be a screw there for the deck support) to the battery and that solved the problem. With 7 amps and a new line driver eq(thanks grant) I was pulling my hair out. or at least what's left of it.

Rob:

I had the same problem and the solution was very simple and very cheap. Before you invest in any pieces of equipment or new gear give this a try, it certainly can't hurt.

Take a wire of reasonable size (14 to 16 awg) connect one end to the frame of the stereo deck (they usually have a stud or similar spot for exactly this purpose) and run the other end directly to the ground of the amps.

What can easily happen is that the amp has a direct connection to the battery so it gets a good, solid ground reference. The deck connects to the regular boat electrical system, so it's ground routes back to the dash, then through a long cable to engine, then through a couple of connections before it finally gets to the battery. The "ground" that the stereo sees is differnt than what that amp sees. The amp will do it's job and amplify any noise it sees as a result. Making a direct connection between the two may quiet things down a bunch.

thanks guys thats what I'm looking for. Lets hope it works

Sounds like a ground issue or a remote lead. You can also take a ground wire and twist it around the remote lead all the way to the amps. Then, connect that ground from the radio to the amp ground. That should filter out any noise.

Ok, got the boat back, I took the above advice and added a much thicker ground directly to where the amp is grounded. It helped but the buzzing is still there. Note: the buzzing is there and the engine is not even running. So any more advice, also is there any benefit of grounding to the engine block compared to directly to the battery? Thanks.

Grouding to the engine block may create antoher loop. How old are your amps? what kind? could be a bad amp. what are your gains set at? Have you checked all your settings on your amp? I've had a sub buzz like a hummingbird b/c I accidentally turned on the bass boost w/o having the remote bass knob pluged in. Can you isolate the buzz to certain speakers or is it all of them?

If the RCA cable is connected there is a buzz. I just bought a ground loop isolator off of Ebay for $11. We'll see if that helps. My player may be bad.

like I said before . It is your deck!!!!!!!

Run speakers directly to deck no RCA's. If this gets rid of the buzzing then it is your deck (RCA's out from deck are bad).

This is most likely the case.

Double U, will check. Buzzing seems to be only on when I'm using the CD player now, and only when volume is down. (Meaning you don't hear it over the music. Of course it could come back when the boat is running.

Could be crappy RCA cables too. I didn't believe before but I am a believer now. Spend a few bucks on good ones, you will be surprised how much better stuff sounds.