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  #11  
Old 04-20-2013, 10:42 PM
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good luck finding it...

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  #12  
Old 04-20-2013, 11:58 PM
djkslc djkslc is offline
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The hiss is constant, and rpm's don't change the hiss. The stereo is clear when the engine in off, but as soon as tge engine is on the hiss starts happening. We tried the isolator trick today and that didn't do anything. He's really frustrated, he thought a new boat = everything is working how it should.
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  #13  
Old 04-21-2013, 12:13 AM
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Start with chasing all the grounds n direct power supplies and work your way down stream. Pull the rcas and see if the noise remains.

Also bypass the head unit and plug your source directly into the amp ie an iPod or iPhone see if it remains.

Where is your gain at relative to max on your amp?
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  #14  
Old 04-21-2013, 08:32 AM
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Quote:
Originally Posted by djkslc View Post
The hiss is constant, and rpm's don't change the hiss. The stereo is clear when the engine in off, but as soon as tge engine is on the hiss starts happening. We tried the isolator trick today and that didn't do anything. He's really frustrated, he thought a new boat = everything is working how it should.
It may sound like hiss, but it's often hard to determine some sounds' characteristics when another source of noise is present (the running engine's exhaust/mechanical noises). WHat is sometimes described as hiss can be digital noise, from wiring that's bundled with cables from the engine that carry digital signals. This is often called 'digital hash'.

If you have long audio cables with RCA plugs, mark the ones in the boat WRT where they plug in at each end and substitute yours, keeping them away from anyother cabling, the driver side combing panel and any other bundles of wiring. If the noise stops, it's entering the cables because of proximity and they'll need to be re-routed. This should be a warranty job.

Another fix that can be used- take a piece of 16 ga wire that's long enough to reach the head unit easily and attach it to the amplifier's ground (any color will do for the test, but use black and label it at both ends if it ends up being the solution, so the color code is maintained). Start the engine and while it's making the noise, touch the free end of the wire to the case of the head unit. If it diminishes the noise, shut off the engine, disconnect the battery negative cable and clip the radio's ground wire AT THE BUTT SPLICE, NOT AT THE HEAD UNIT, strip the end and install a ring terminal (crimp and solder this- it's important that there's as little resistance on this connection as possible). Attach this AND the ground wire to the head unit's case, reconnect the battery negative cable. Your noise should be gone at this point.

If it stops, route the wire to the head unit and secure it to the case, using the screw that should be holding a metal back strap on. If this doesn't work, touch the wire to the shield of one of the RCA cables at the amp. If the noise stops, solder the end to the RCA cable's shield.

Another possible solution has to do with eliminating the red and yellow wire voltage/current sources in the boat harness. You would need a piece of 12 ga wire and a Bosch-style relay but for the test, just the wire is necessary. Disconnect the battery - cable, attach this new wire at the amplifier's + terminal, clip the red and yellow wires for the head unit AT THE BUT SPLICES, reconnect the battery - and run the engine. If the noise is gone, you'll need to re-route the wire to the head unit and connect the relay. You'll end up using the red wire in the dash to switch the relay but the voltage/current source will be the new wire. If it works, I'll post a diagram for the relay's connections.
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  #15  
Old 04-21-2013, 08:33 AM
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Quote:
Originally Posted by swatguy View Post
Where is your gain at relative to max on your amp?
99.9%?
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  #16  
Old 04-21-2013, 09:34 AM
djkslc djkslc is offline
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The gain was at about 80%, I turned them down to zero and the noise was still there. We did pull the power to each amp and the noise continued. I also pulled the RCA lines from the back of the head unit one by one and the noise continued. I think he is going to take it back to the dealership one more time. They farm the stereo stuff out to a local car stereo place, but I think it is getting lost that the boat needs to be running. They keep saying its fixed and then as soon as the engine is turned on the noise is still there.
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  #17  
Old 04-21-2013, 10:03 AM
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Originally Posted by djkslc View Post
The gain was at about 80%, I turned them down to zero and the noise was still there. We did pull the power to each amp and the noise continued. I also pulled the RCA lines from the back of the head unit one by one and the noise continued. I think he is going to take it back to the dealership one more time. They farm the stereo stuff out to a local car stereo place, but I think it is getting lost that the boat needs to be running. They keep saying its fixed and then as soon as the engine is turned on the noise is still there.
If you pulled the power to each amp and the noise continues and you're positive that it's coming from the speakers, the routing of the speaker wires and something else is causing it. Can you disconnect a speaker to find out if it definitively stops the noise? Is there any chance that the noise is the fuel pump and it sounds like it's coming from the speakers?

If they farm out the stereo work, make sure they supply cooling water- you'd be surprised by the number of people who think a boat can be run out of water.
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  #18  
Old 04-21-2013, 01:50 PM
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Come to think of it. My 2012 X25 had a same hiss/hum that was always there as soon as the boat was turned on and the stereo was turned on. I assumed it was normal.
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  #19  
Old 04-21-2013, 02:35 PM
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Well if the noise is still there after yanking the rcas is coming from downstream of the head unit so you can rule that out. By "pulling the power" to the amps do you mean you pulled the power leads off and the amp was not on? Or do you mean you "pulled the power" by just not feeding it any music signal?

If the amps were completely powerless an you still heard the noise you are likely getting interference down the speaker wires. Next step is to disconnect all the speaker terminals from the speaker itself. I would also check each and every speaker sound wise. You may have a blown speaker/tweeter. Another culprit could be an exposed speaker wire. Sometimes happens during the install when feeding wires through. They tug and pull and it can strip the wire shell exposing the copper portion. There are sharp edges all around the boat. Not sure if your speakers are soldered on or clipped on with spade connects,but try pulling the leads one by one on the back of each speaker to see if that rids the noise.

Good luck keep us posted
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  #20  
Old 04-21-2013, 06:37 PM
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Quote:
Originally Posted by Nick911 View Post
Come to think of it. My 2012 X25 had a same hiss/hum that was always there as soon as the boat was turned on and the stereo was turned on. I assumed it was normal.
Hum is one thing, hiss is another. A ground loop won't cause hiss but radiated interference can cause what sounds like hiss.
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