Stereo popping with trim adjustment
 

Hey guys I have Kenwood head unit with 2 JL Audio amps powering 6 6x9's. Every time I adjust the trim up or down I am getting popping noises from the speakers. I have had this stereo installed for 3 seasons now and it only started doing this last season. I tested all 4 optima batteries and verified that they are good. My amps are grounded to one of the batteries. I have also tried hooking up the ground wire from the head unit directly to the battery and it still pops. Any troubleshooting ideas? I appreciate any help. Thanks.

Add a noise filter like the one below to your 12 Volt input. They're effective, easy to find, easy to install and there's no downside.

http://www.crutchfield.com/p_003S15A...dNoise+Killers

You can also try a ground loop isolator on the RCA inputs of the amp. That may be more effective since your amps are what is providing the output to your speakers. My boat has alternator whine if I select battery 2 and listen to the stereo since that is the battery my amp is coming from. If I run the boat (engine running) with battery 1, its no problem, but isolators will help in most cases.

check all of your ground connections...

Since you said that the systems been running fine for the past 3 seasons and its only starting now i would lean to either a bad/loose ground, The switch for your trim going bad internally...or the brushes on the trim pumps wearing out. Unless theres somethig else thats changed you are not letting us know about.

sleev-les...the alt whine your getting....are the RCA cables from the head unit going to the amps running along side any power wires? If so you would want to make any crossings at 90* of each other to keep noise down if possible or sepperate them as much as possible.

loose ground on an amp or something in the same path. the worst way too cure ground loop is with and isolator in the Rca. It takes away the freq that the whine is at also eliminating that portion of sound i.e. the music. Ground loop is caused by a bad ground or something causing the signal to bleed into the RCA's like a power line or a bad rca.

i had a similar problem and it turned out to be a bad amp. Never thought the amp was the culprit. was working great one weekend and next was getting all kinds of pops static and noise. If grounds dont fix it, try testing without the amps completly. Disconnect power connections and reconnect speakers to head unit, or find a loaner amp.

Thank you guys very much. This morning I tried isolating the deck directly to the Perko switch and grounding it to the battery but it still popped. I have also checked the grounds going from the batteries to the engine as well as the trim to the engine and all are good. I'm going to try connecting the speakers directly to the head unit and see if it that works. I never though both amps could go bad but I guess its always the problem you suspect the least. Thanks again guys. I really appreciate it.

Got it!!!!!! So Steve I followed your advice and connected a speaker directly to the head unit and there was no issue whatsoever. I then called a local stereo shop and asked them about testing my amps. I told him it was strange that both amps would go bad. He asked if they were both powered off the same distribution block, which I told him they were. He said that all speakers would pop because the bad amp would relay the interference to the good amp also. So I unplugged one of the amps and the popping stopped completely. I'm on the way to replace the one bad amp. Thank you guys again. Lifesavers! Now I can make it to Havasu without popping in two weeks!

Nope.. Audo 101 lol.. Only right at the amp power and signal are close, but they are still separated. I may go for some better RCA's

Yep lol :D but i'm still surprised at how many people dont know that :)

If you suspect your RCA's are getting interference then try and wrap them in aluminum foil and see if it blocks the interference...could save you some cash, why replace if they are not the problem

Replacing them doesnt cost much.. Having a part time job at Best Buy gives a hell of a discount on cables.. I paid 5 bucks per set. The other good thing is I try out different things before buying them so if its not the rca's, I'll try something else.. We usually have extra laying around the shop and it helps to troubleshoot..

Really, all you needed to do was spend 3 dollars on a capacitor for your distribution block. The impulse caused by the trim tab relay is easily removed by a cheap filter (or capacitor) rather than hundreds of dollars for a new amplifier.

The ground loop isolators suggested by others are for removing 60 Hz noise and there's no such thing in a boat.

Do not wrap your cables in tin foil. That's really ghetto and will do no good.

People always misunderstand the purpose of grounding (and there's no such thing in a boat).

Okay so the pop came back after I removed what I thought was the bad amp. Luckily I didn't make it far enough to purchase new amps. Nighthawk, can you please tell me more about this capacitor please?

I found this link through another forum. Is this what you are referring to?

http://www.earmarkcaraudio.com/Xcart...7&cat=0&page=1

That one is $12.00, must not me the right one.

Okay so I went to Radio Shack today and got these

http://www.radioshack.com/product/in...ductId=2103625

It was a little over $6 because I had to get 2 for the trim control on the throttle and 2 for the transom trim switch. I wired them in and the popping stopped completely. Thanks again guys for all of your time and help.

Haven't checked in for a few days. Glad to hear that fixed it. The noise filter link I sent you in my first post is nothing more than a capacitor and series inductor in a nice package but just a capacitor usually does the trick.