Stereo noise issues
I have a Supra 21V and still have noise issues in my sound system. I have a MB Quart head unit with 2 amps. One amp is running in boat speakers and sub. The other is a Wetsounds amp running 2 Rev10s on the tower. When I pause the music or listen to it at a low volume I hear a "static" type white noise that is very annoying (regardless of whether boat is running or not). I have read about running the power from my head unit directly to the battery or amp. Is that what I should do? The noise is in both the in boat speakers and tower speakers. Right now it runs to a switch on the drivers panel so I can turn the stereo off with that switch. I hate to lose this functionality but will do so if needed. Right now the gain on the Wetsounds amp is turned down to about 35% or less to help reduce the noise but this makes it hard to hear the speakers when boarding. Please help if you can!!! I am not an audio guy but am handy enough to follow logical directions.
I had the same problem as you with a bad ground loop. I tried cleaning my grounds, ground loop isolator, rerun my wires and nothing worked. I have so many rca, speaker wires, and power wires runing over the top of each other also. I rewired my deck straight to the battery, and it is perfect now. What is weriod is that I installed the stereo and no ground loop. As soon as I added more stereo components the ground loop came out. I had my deck wired up just like yours also, and it was nice to turn it on and off with the breaker on the drivers console. But, I like it wired straight to the battery. Becasue when you turn the boat on and off, you don't get the pop from the deck turning on or off.
Try unplugging the video feed from the head unit to the supra vision. This worked to get rid of the buzzing sound on mine. There is a defect on these head units and somehow there is a problem with the dvd player causing this noise on a lot of these MB Quarts head units.
Originally Posted by h2oboy22
2011 22 SSV
Does your boat have a dual battery setup with switch? If so, does it have an ACR/VSR isolater/combiner? A constant hiss/buzz/static type noise that is present with the engine off and doesnt change with the engine running, and is omitting from speakers powered by both amps, leads me to believe its being generated by the source unit, or at least upstream of the amps. With a dual battery system, its crucial to have ALL the stereo electronics sharing the same voltage reference. This includes SAT receivers, EQ's, and PM3 interfaces that charge the players.
Originally Posted by h2oboy22
This can be achieved by relocating the head-units ground and B+ wires from the OEM oat harness to either the amp, the amp's distribution blocks, battery or switch, depending on some other factors. Go with the closest/easiest/cleanest run.
Now, for those of you using a helm toggle switch to turn the head-unit on/off, the above should not effect this. Just about every head-unit made in the past decade has 2 "power" wires. The one we need to relocated as described above, is the yellow B+/MEM wire. This is the one that the head-unit actually draws its load on. The wire you guys need to run to your helm switch is the red "turn-on" wire. This red wire does for the head-unit, what the head-unit's blue amp turn-on wire does for the amps. its simply ay 12V signal for the head-unit to "wake up".
Now, the next leading cause of unwanted noise thats heard with low volume or no music playing, is gain-hiss. With the tower amp gain turned down to 35%, sounds like it should not be a problem, but I would recommend setting the gain on both amps using a gain setting procedure, rather then going off clicks on a dial.
With things as the are, disconnect the RCA cables from both amps and power the system up. Listen to see if the noise is still there. If so, its generated in the amp. If gone, we know its upstream. If you have an RCAx3.5 cable, plug it into the amps and play some music at low volume and see what the noise does. Let us know about the battery and switch setup and we can offer some specifics about the head-unit and amp rewiring.