Having Trouble With Tower Speakers!

[pieperk]

So I have a 2007 Moomba Outback V. It has stock speakers and amps, all kicker. The interior boat speakers work fine (with a small amount of buzz, if you know why this is please tell :)), they are hooked into a kicker ZX700.5. But the tower speakers are a different story. I got them working while the engine not on and is on land (lots of buzzing, but can still hear the music), but when the boat goes in the water and we are going all they will do is buzz.
The towers are hooked into a Kicker ZX250.2 amp.
Please help, I have been trying to fix this for a very long time and am getting frustrated.
Thanks!

[wolfeman131]

you'll get better advice from the pro's on here, but start by checking your grounds, loose connections, etc.

[kaneboats]

Moved thread to the right place. These pros will definitely help you out.

[David Analog]

There are many forms of noise on a boat that are inherent in every boat. The alternator, blower motor, and many other devices can introduce an AC ripple (whine or buzz) or transient snap or pop (voltage spike) into an otherwise DC electrical system. Normally this noise does not have a path into the audio system.
So to determine the type of noise, let's start with the most common alternator noise which is described as....Only present when the engine is running and not with the key on while the engine is not running. Changes pitch with an rpm change. Faster revs creates a higher pitch whine. Whine level is essentially the same at all volume levels. Noise will be somewhat masked by an increase in volume level and will be extremely obvious at lower volume levels. That's alternator whine. If that description doesn't match your noise, give a detailed description.

[David Analog]

The number one cause of noise is a supply voltage differential or ground differential (basically the same condition) between any two items in the audio path. To remedy this ALL 12 volt supplies of ALL audio components must reference the same physical point....and....ALL grounds of ALL audio components must reference the same physical ground point.
The ground point is the ground terminal on one of the batteries. You may access this ground via a distribution block.
The 12 volt supply point should be off the 'C' output post of the dual battery switch (and not battery-direct unless you have an ACR/VSR scheme). You may access this 12 volt supply via a distribution block.
Both + & - distribution blocks need to be very near the amplifiers. ALL source electronics (HU, EQ, etc.) need to obtain power and ground from these two respective points. Sometimes this means that the source electronics need to come off the factory harness and be re-directed to the points mentioned above with a suitable heavy gauge (low resistance) wire (typically 14 to 16-gauge).

The other and second most common condition that multiplies noise is when the amplifier input gains are set wide open. There is virtually never a good reason for wide open gains.

Before you get going, check the voltage of BOTH batteries independently. Doesn't make much sense to start initiating changes with bad voltage or bad batteries.

[pieperk]

Ok, so it doesn't sound like the body speakers are being affected by the engine being on.
However, the only thing that can be heard from the tower speakers when the engine is running is noise, no music can be heard.
The power and ground wires both run through a fuse each, but other than that they are direct to the battery.
Does that help narrow the problem.
The speaker wire is very small, but it is the same as the body speakers, so would that matter...?

[David Analog]

Ok, so it doesn't sound like the body speakers are being affected by the engine being on.
However, the only thing that can be heard from the tower speakers when the engine is running is noise, no music can be heard.
The power and ground wires both run through a fuse each, but other than that they are direct to the battery.
Does that help narrow the problem.
The speaker wire is very small, but it is the same as the body speakers, so would that matter...?



So you are saying that the tower speakers play music when the boat is off but have a great deal of noise, but absolutely no music when the boat is running, and the noise is then significantly higher. Is the key off or out when you have noise at rest? You must have all boat operations off and no key insertion/rotation. You may have to go straight to constant power and bypass the key if the audio system is dependent on key power. And you have to find a condition in which you have zero noise. That's the beginning. If you still have noise with all boat electrical operations shut off then the problem is independent of boat electrical system and within one of the stereo components or within the installation. To help you I need all the information requested from you in a concise manner.
I would also start testing gear piece by piece independent of the boat. Perhaps with a battery sitting on your garage floor. Start with just a tower speaker and a single speaker. You can use an ipod or iphone directly into the amplifier input. Start with the last component in the audio system and work upstream (backwards) until you obtain a change. Then you will have a defined area to focus on.
Also, try disconnecting both tower speakers and circumventing the tower harness entirely. Then hook up one speaker only with a new and temporary wire run directly to the speaker. All it takes is one tiny strand of one speaker wire to short out and you can have serious noise induced into the entire system.

[pieperk]

Ok, so I did the speaker tests without the key and still had some trouble, tried a direct line to the speaker and the same quality. So I took apart the entire system and rearranged a few wires (some of the RCA cables to the speakers were in outlets for subs.). In short, it sounds great now WITHOUT the key turned.
However, when I turn the key the sound instantly gets more grainy. I am thinking this is a grounding issue, what are your thoughts?
Thanks

[David Analog]

I would want to hear one tower speaker resting on the floor with a brand new run of wire and ALL else disconnected. That would exclude a speaker shorted to the tower via the speaker wire harness.
Then, use a relay to recreate the key interrupt function and connect the source unit power and ground to the same respective locations as the applied to the amplifier's primary power terminals. If the noise goes away you have a solution for the short term but the knowledge that something is wrong and will likely progress.
Beyond that I would question every single ground in the entire system including all audio equipment grounds, the battery to battery grounds, helm buss ground, and ground link from the engine block to battery.

[pieperk]

When you say that "ALL else disconnected" you mean with the speaker connected to the amp, which is connected to a battery and an RCA cable connected to an ipod right?

Also, thought I had it fixed last night so I took the boat out. Tested the sound before I went out, played perfect. Dropped it in and started the boat, tons of noise, and then half of the boats speakers shut off (literally, the drivers half). The other sides body speakers still worked but only very dimly. They didn't put out much.
The only speaker that was working was the tower speaker opposite the driver. This speaker put out fuzz too, but the interesting thing is that when I turn on a bilge, or rev the engine, or any other switch, I could hear it in the speaker!

I am continuing on the testing you have suggested.
Please help, I am extremely confused. I haven't charged the batteries in a bit, so could this be an issue with it.

[David Analog]

I'm trying to help but this isn't productive thus far.
It is pointless to conduct any diagnoses until you have measured and confirmed that you have healthy voltage.
It is pointless to chase down the cause of noise when you have major system failures.
And I have a feeling that when the installation is corrected that the noise will be gone.
You must have a dependable foundation to build upon.
Let's start from scratch. Get a decent multimeter and read the manual until you can measure 1) DC voltage, and 2) DC resistance in your sleep. Then we can pick it up again and save you a ton of time and frustration.