High pitched noise coming through in-boat speakers

[dezul]

Background:

Last summer I ask the crew almost the same question. See link below. Well, over the summer the noise still existed but my amp started dropping channels. By the end of the summer the only channel that worked was the subwoofer channel. The amp was the Alpine 5 channel that comes in SP2. So I swap out the 5 channel amp for an Arc Audio 800.5 amp which now leads me to my current issue.

http://www.themalibucrew.com/forums/index.php?/topic/48381-another-pesky-ws-420-question/?hl=noise

Current issue:

I am getting a high pitched noise from my in-boat speakers that are connected to the Arc Audio 800.5 amp. The noise is in the range of 8k - 10k hertz. This noise happens when the boat is not running and the ignition switch is turned backwards to play accessories. My setup is the stock Sony deck going to a WS420 which then going to two amplifiers. My Sony deck and WS420 are both wired directly to the power distro block that the amps are wired to so everything has a common power and ground from the same source.

My current setup is a PPI 900.4 going to a pair of Rev 10s. The PPI 900.4 has a ground loop isolator on it. Last night I put a ground loop isolator on the Arc Audio amp and it toned down the music and noise a lot compared to without it.

Things I plan to try:

If I can find my 3.5mm plug to RCA cable, I plan to disconnect the WS420 and plug my phone directly into the amp to see if the noise continues. That should identify any issues with my amp right? If the noise goes away from that test, then I plan to do the same thing to the WS420. If the noise goes away when testing the WS420, does that mean the main issue will be my head unit?

Edited April 9, 2015 by dezul

[Ridebutter]

That sounds like a good troubleshooting plan. Report back your results. Are your batteries charged and fresh? Are your power and ground connections solid?

[dezul]

That sounds like a good troubleshooting plan. Report back your results. Are your batteries charged and fresh? Are your power and ground connections solid?

Everything seems solid to me and the batteries are fully charged.

[cjtpilot]

you have a loose or bad ground.

[MLA]

Since the tower amp and in-boat amp are fed by the same head-unit source, through the EQ, seems that the issue is between the amp and the EQ, not head-unit. Do this, swap the tower and in-boat outputs at the EQ and see if the issue stays or moves. Next, grab a spare RCA and jump right from the EQ to the amp to eliminate the installed RCA. if you think its isolated to the amp, use the rear inputs to see if the noise goes away from the rear speakers when it was there before when driving all chnls using splitters.

[tebbs]

I had an issue like this in my truck. My problem was a bad RCA cable. It looked like everything was making a good connection but one wasn't tight and would cause the speaker to make that high pitched noise.

[dezul]

I had an issue like this in my truck. My problem was a bad RCA cable. It looked like everything was making a good connection but one wasn't tight and would cause the speaker to make that high pitched noise.

I am starting to think this is the issue.

[David]

dezul,

Yes, you need to isolate the point in the signal path where noise is entering. But you need to follow a certain trouble-shooting logic.

You don't need another substitute source to narrow down where the noise is entering at this point. An alternate source only indicates whether you have a relationship issue between two given components, like for example, a mismatch in the RCA ground shield reference to true ground. So this could actually mask what you need to find out.

For right now, try these series of steps.

Start at the very end of the signal path with the amplifier. Fully open up it's input gains with no RCA connected. See if you have noise. If you have no noise report back. If you have noise then short the input of two channels (L & R) (either F or R) by using an RCA cable between the two inputs. Disconnect all outputs but just the two test channels. If you have no noise report back. If you have noise then plug back in the original long RCAs to the test channels and use an RCA barrel connector to short the opposite end. If you have no noise report back.

[ac88926]

My dealer said to replace the RCA splitters at the amp. They said they have this problem all the time

[5inthesun]

I had a similar high pitched noise. It was my headunit. They replaced it and then it went away.

[2manyhobbies]

Mine had horrible feedback to the point of not being able to use the sound system this weekend. I took it back to the dealer tonight and they said they have seen a number of the new VIper2 systems causing this feedback and have had to replace a few of them because of it. They're going to make sure it's not a ground loop and put an isolator on the system as well and replace the head unit if necessary. I'll post up when they figure it all out.

[dezul]

Update:

I finally got my hands on some spare rca's that were long enough to reach the amp from the ws420. The noise is still in all the speakers. Even with all the rca's unplugged from the 420 I hear the noise in the speakers. I am guessing it is a ground issue from the amps to the batteries which are both located in the same compartment. Any suggestions? Charge the batteries and ensure they are full of water? Disconnect one battery? Readjust all the connections?

[dezul]

Found it. I just turned the radio and start wiggling wires. It turned out it was a loose ground on the tower amp.

[teamerickson]

Great news. I was thinking maybe you were listing to Skrillex and got confused.

[dezul]

Great news. I was thinking maybe you were listing to Skrillex and got confused.

Sounded like it...except it had some country twang.

[joshuadale07]

I'm having the same problem, but mine seems to be the amp. If I turn down the gain for the in boat speakers the noise disappears, turn it back up and the noise slowly comes back. Don't know if I need a new amp, or if this can be fixed

[miked272]

Grounding the chassis of the head unit also helps eliminate phantom noise when all else fails.

[dezul]

Shortly after I wrote I had the solution to this, my in-boat speakers started making the noise. Today I finally figured it out. It was a bad pair of rca cables. Switched them out. So I basically had two issues. One amp had a bad ground cable and the other amp had some bad rca's. I hope I don't have anymore stereo issues this year...or any issues at that.