Noise Issue

[lewisb13]

So im trying to help my neighbor with the x2. I havent done any troubleshooting and will start that tomorrow. It has a noise issue with the tower speakers when the rcas arent even plugged into the head unit. So im assuming either the rcas are run to close to a power wire somewhere or theres a problem with the amp. Any thoughts?

Second question. I have the zld and I know all about the ws420. Whats the cheapest fader thats out there? Is it the throttle box? The owner doesnt care so much that he just wants me to mount it where the batteries are because he is confident he will only want to fade once in a while.

[jmvotto]

Make sure head unit is grounded to the same ground as the amps.

Clarion 476 eq can be had for 50 bucks all over ebay.

[beat taco]

The x25 gave us fits until I pulled a new power lead to the head unit.

[MLA]

RE - noise: Not sure I fallow, is there a noise issue with the RCA's properly connected? If so, describe the noise. Is the noise present with the RCA disconnected from the amp? The next question is if this boat has a dual-battery setup, where are the amp's B+ cables connected?

2nd question: What are you looking to accomplish? Are you referring to the exile throttle box for the harpoon amp only? Too my knowledge, it does not fade or control volume. There are some EQ's out there that function exactly like the ZLD that can be had for $35.00. They fade.


ThrottleBox Remote Controller
Allows the user to actively shape the sound of HLCD speakers depending on the real world listener position i.e. wake boarding (far out), wake surfing (close in) or cove (stationary)

The least expensive means to control the volume of an amp, besides the head-unit fade, is to use a line level POT. But by time you go with 2 so you can control 2 amps, plus the 4 long RCA pairs, you are approaching the cost of an actual marine zone controller like the Kicker ZXM-RLC, which is also a 9v p/chnl line-driver.

[lewisb13]

The best way I can describe it is static. Its not the high pitched whine. It happens whether boat is running or not amd whether rcas are plugged in or not. And he doesnt have an amp to his cabin speakers so he will just be fading between the tower and nothing. So a potentiometer will be just fine, any suggestions? Both amps are powered and grounded from the same battery.

[MLA]

Just be aware that RCAs disconnected at the amp is an entirely different scenario than just unplugged at the head-unit, so use both during your testing. An issue with the RCA will still be there as long as the RCA is connected to the amp and disconnected from the head-unit, but will go away once the cable is pulled from the amp. Unwanted noise with no source cables connected to the amp could indicate an internal issue with the amp. it may just be excessively high gain settings. I would start by lowering the gains to below half if they are above. Although this is not an accurate setting, its low enough that it should reduce the noise if it is due to high gains.

[EarmarkMarine]

If you want to fully eliminate the RCA cables as a potential noise magnet then unplug them from the amplifier and short the left and right RCA inputs with a short RCA jumper.
Triple check the amplifier ground.
Run the amplifier input gains no higher than 50%.
If the noise is a random hiss like the sound of a distant waterfall whenever the amplifier is 'On' but the boat ign./acc. is 'Off' and the amplifier inputs are shorted then that is likely an internal product of the amplifier.
If you had a shorted speaker lead then the amplifier would probably pick up alternator noise but also every boat switching transient.

David

[lewisb13]

Thanks for the replies! Ill try unplugging the rcas today and seeing what happens. Im going to turn the gain down on the amp as well because the cabins and the towers dont rise in volume proportionately. Any suggestions on some line level pots?

[EarmarkMarine]

PAC LC-1.

Don't just unplug the RCAs....short them from L to R.

David

[lewisb13]

Ok so I triple checked, b+ and b- are all on same battery. Jumped the rcas, no change. Turn the gain up or down with no rcas plugged in at all, no change.

[EarmarkMarine]

Ok so I triple checked, b+ and b- are all on same battery. Jumped the rcas, no change. Turn the gain up or down with no rcas plugged in at all, no change.

Lewis,
Okay, the speaker grounds are common to the RCA shield ground on most topologies. So if you have a grounded wire in the tower harness it can deliver any noise directly to the amplifier input. This might mean that you have a second B+ short in the tower. A tower can conduct. Use a test speaker laying on the floor with a new wire laying on the floor. Disconnect and short the amplifier inputs. Now you are 100% isolated from any audio equipment and wiring in the boat except for the supply. If you still have noise under these conditions, then you have an issue with the amplifier which may be unable to reject the normal noise common to every boat. If the noise disappears then start checking the tower harness. Keep in mind that you cannot read a short on the capacitor-coupled tweeter.

David