White Noise from Tower Speakers

[cpropes2005]

I have been chasing a noise problem in my stereo ever since I installed tower speakers. Basic symptom is that I get white noise through the tower speakers. It is very noticeable when the volume is set to 0 or when the music is paused but it is still there if you turn up the volume, it is just masked by the music. It does it with the engine off so it isn’t alternator noise. Other weird thing is that it is present on both channels but it is much louder on the left channel.

My setup consists of the factory fusion hu and the factory option for the kicker km800.5 to power the in boats and sub. When I added the tower speakers I started with a cheap crappy amp but recently upgraded to a kicker km400.4 thinking that might help solve my issue. On both the old amp and the kxm400 I had to utilize the high level inputs since the factory fusion hu only has one pre-amp out and I really wanted to keep the zone control functionality of the stock hu/transom remote.

So far I think I have traced it all the back to the hu and specifically the speaker level outputs. First thing I did was swap the inputs on the amps so the in boats was using the high level and the tower was using the factory installed low level. The noise went away in the tower speakers and appeared in the in boat speakers so that narrowed it down to the high level output signal coming from the hu. I was thinking maybe the way I routed the wire for that signal up and around the bow of the boat was picking up something so I disconnected that wire and just ran a temporary signal wire from under the dash through the cabin and directly to the amp so that I could be sure it wasn’t routed near a power cable but the noise was still there. The last thing I tried was installing a kicker line out converter right at the hu and then running an rca to the amp so that the amp would see a low level input but noise is still there. I did notice that htere were some adjustment screws on the line out converter but I havent had a chance to play with those yet.

Any suggestions? Ground issue with the hu? I have the factory dual battery setup and when I added the second amp I just used the power and ground blocks that are located on the amp mounting board. I have played with the gains but maybe I need to turn them down further? Make adjustments to the tone from the eq on the head unit? Would it matter which pair of speaker outputs from the hu I used for signal (I think I used front left and front right)?

[BrettLee3232]

I have same issue. Was wondering if ground loop isolaters would solve it?


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[BrettLee3232]

I've used this before on a commercial speaker install and fixed the humm

http://www.walmart.com/ip/48806857?wmlspartner=wlpa&adid=22222222228036309888&wl0=&wl1=g&wl2=m&wl3=57513388898&wl4=&wl5=pla&wl6=89879294018&veh=sem


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[trayson]

Personally, I stay away from high level outputs like the plague. I would insert a WS420sq or an Exile ZLD to keep your zone control.

That said, if you insist on using your high level inputs, are you turning down the gain on the amplifier that it's going to? I'd imagine that could help.

[MLA]

GLI's mask the issue, rather than fixing it, so steer clear for now.

1st, where did you connect the new amp's B+ (power) and ground cables and does the boat have a dual battery setup? Its is ABSOLUTELY important that ALL the stereo equipment share the same battery reference.

Next, can you give me a run down on the amp settings and RCA configuration?

The fact that you can move the hi-lever to the in-boat amp and RCAs to the tower amp and the noise moves with the cable swap. tells us a lot, thats a good start.

Beyond the noise, I would highly consider the Kicker ZXM-RLC dual zone volume control. It not only gives you fingertip volume control, but it solves the single RCA output of the 205, without splitting the RCAs. Its a line driver as well. But lets try to resolve the noise before adding new gear.

[David Analog]

I would not hesitate to use a raw high level HU output going to a subwoofer provided that the amplifier input range could facilitate that much voltage. But this is usually problematic when running fullrange or highpass.
If you are using a high to low level adapter, the long wires should be speaker wires and the adapter should be located closest to the amplifier inputs. The adjustment on a hi to low level adapter is an integral part of this component so it is essential that this is correctly adjusted.
Ground loop isolators have their application but not normally in this circumstance. They function by creating an AC-only link between the two audio components so that DC cannot pass down the ground shield. I wouldn't think this is applicable to white noise (hiss).
For a low noise floor, one of the worst things you can do is take a roller coaster ride in up and down line voltage. Since you only have a single pair RCA, and it is likely very weak voltage, you should use a line driver (like MLA suggested). This should solve your noise problem and will restore you zone control.

[cpropes2005]

Yes I do have dual batteries and the power and ground for both amps are hooked up to the distribution block that came from the factory in the passenger side storage. I haven’t looked but the batteries are only a couple feet away so I am guessing the + comes off of the battery switch and the – goes back to one of the batteries? I will take a closer look at exactly how they are wired. Not sure exactly how the hu gets power since it is on the other side of the boat.

I will re-arrange the hi low adapter to where it is closer to the amp instead of the hu. Is there a defined process for how to adjust these things? The one I got didn’t come with any instructions (Kicker KISLOC). Just turn the screws and see if it makes a difference? I think I actually have a gli at home so I might just try it to see what it does but still work on solving the root of the problem.

Honestly I know deep down that a line driver is the way to go for the best audio quality but I am trying to fight it. I had one on my last boat and it worked well with no complaints but I actually really like the simplicity of how the fusion unit does zone control and the bigger issue is that I don’t want to lose the ability to control volume/zones from my transom remote.

To do list for me: 
1. Re-locate hi lo adapter to near amp
2. Play with adjustments on hi lo adapter
3. Turn gains way down on amp and see if noise goes away
4. Take a picture and/or record my amp settings
5. Figure out exactly how everything is getting power

[cpropes2005]

Side note, why on earth did fusion only put 1 rca out on this unit?? I cant imagine it costs much for them to add another pair of outputs and I would guess most boats that are using these would like to have more than one amp.

[BrettLee3232]

Yes I do have dual batteries and the power and ground for both amps are hooked up to the distribution block that came from the factory in the passenger side storage. I haven’t looked but the batteries are only a couple feet away so I am guessing the + comes off of the battery switch and the – goes back to one of the batteries? I will take a closer look at exactly how they are wired. Not sure exactly how the hu gets power since it is on the other side of the boat.

I will re-arrange the hi low adapter to where it is closer to the amp instead of the hu. Is there a defined process for how to adjust these things? The one I got didn’t come with any instructions (Kicker KISLOC). Just turn the screws and see if it makes a difference? I think I actually have a gli at home so I might just try it to see what it does but still work on solving the root of the problem.

Honestly I know deep down that a line driver is the way to go for the best audio quality but I am trying to fight it. I had one on my last boat and it worked well with no complaints but I actually really like the simplicity of how the fusion unit does zone control and the bigger issue is that I don’t want to lose the ability to control volume/zones from my transom remote.

To do list for me: 
1.Re-locate hi lo adapter to near amp
2.Play with adjustments on hi lo adapter
3.Turn gains way down on amp and see if noise goes away
4.Take a picture and/or record my amp settings
5.Figure out exactly how everything is getting power

I used the zone controls (bow, cabin, tower & subs)

The transom remote still controls main volume but if someone is in the bow or cabin at anchor I can turn those zones off and just do tower speakers for when were floating in the water.

I love having 4 zones!!!!

[BrettLee3232]

Yes I do have dual batteries and the power and ground for both amps are hooked up to the distribution block that came from the factory in the passenger side storage. I haven’t looked but the batteries are only a couple feet away so I am guessing the + comes off of the battery switch and the – goes back to one of the batteries? I will take a closer look at exactly how they are wired. Not sure exactly how the hu gets power since it is on the other side of the boat.

I will re-arrange the hi low adapter to where it is closer to the amp instead of the hu. Is there a defined process for how to adjust these things? The one I got didn’t come with any instructions (Kicker KISLOC). Just turn the screws and see if it makes a difference? I think I actually have a gli at home so I might just try it to see what it does but still work on solving the root of the problem.

Honestly I know deep down that a line driver is the way to go for the best audio quality but I am trying to fight it. I had one on my last boat and it worked well with no complaints but I actually really like the simplicity of how the fusion unit does zone control and the bigger issue is that I don’t want to lose the ability to control volume/zones from my transom remote.

To do list for me: 
1.Re-locate hi lo adapter to near amp
2.Play with adjustments on hi lo adapter
3.Turn gains way down on amp and see if noise goes away
4.Take a picture and/or record my amp settings
5.Figure out exactly how everything is getting power

I used the zone controls (bow, cabin, tower & subs)

The transom remote still controls main volume but if someone is in the bow or cabin at anchor I can turn those zones off and just do tower speakers for when were floating in the water.

I love having 4 zones!!!!


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[David Analog]

You have established the following per your posts.
You have noise anytime you use the HU speaker outputs to amplifier inputs.
You have noise with any amplifier when running from the HU speaker outputs but not with any amplifier when running from the HU preouts.
You have noise with or without a line level convertor.
Based on that, I'm coming to the conclusion that no matter what you do, if the noise persists, even after adjusting gain levels, then you have to run 100% preouts. The HU speaker level output section may not like any termination other than push/pull through a typical speaker impedance.
Chasing grounds and other issues isn't making much sense, since you have scenarios with the same equipment that is noise free.
A line driver/controller may be inevitable.

[MLA]

Yes I do have dual batteries and the power and ground for both amps are hooked up to the distribution block that came from the factory in the passenger side storage. I haven’t looked but the batteries are only a couple feet away so I am guessing the + comes off of the battery switch and the – goes back to one of the batteries? I will take a closer look at exactly how they are wired. Not sure exactly how the hu gets power since it is on the other side of the boat.

I will re-arrange the hi low adapter to where it is closer to the amp instead of the hu. Is there a defined process for how to adjust these things? The one I got didn’t come with any instructions (Kicker KISLOC). Just turn the screws and see if it makes a difference? I think I actually have a gli at home so I might just try it to see what it does but still work on solving the root of the problem.

Honestly I know deep down that a line driver is the way to go for the best audio quality but I am trying to fight it. I had one on my last boat and it worked well with no complaints but I actually really like the simplicity of how the fusion unit does zone control and the bigger issue is that I don’t want to lose the ability to control volume/zones from my transom remote.

To do list for me: 
1. Re-locate hi lo adapter to near amp
2. Play with adjustments on hi lo adapter
3. Turn gains way down on amp and see if noise goes away
4. Take a picture and/or record my amp settings
5. Figure out exactly how everything is getting power

1) im not sure thats as important with the KISLOC as it is with other simple hi to low adapters. Even then, you will still need a very short RCA with males on both ends.
2 & 3) I would set these to their lowest points now in order to eliminate the noise and worry about output later
4) really need to know this and how the RCAs are connected to the amp
5) although i dont think this is a typical ground loop issue, i still like to cover the basics and make sure all the gear sees the same battery voltage. Working on a 2015 MC with noise issues and the amp is wired to the cranking battery and the one amp is wired to the house battery from the factory and there is noise when the engine is running. So, even the best with the best gear can have some issues from the factory.

[philwsailz]

All arrows point to a need to use a dual zone splitter. Or better yet a line driver like the ZXM-RLC

I'm with David and Mike. Using the high-level out does not appear to be a workable solution.

Phil
Kicker

[cpropes2005]

Well it started raining before I could get all of the testing done but I took out the hi lo converter to move it closer to the amp and before I reinstalled it I decided to play with the gains using the original setup of hi level inputs on the amp. I found that with gains at half way the noise was still there but if I turned them all of the way down it went away so maybe this is just a case of me not taking the time to properly tune the system yet? I didn't get a chance to slowly turn the gains back up to see exactly where the noise comes back but honestly the speakers where still plenty loud for my use with them all of the way down so I will probably just leave them that way until I get the time/space/knowledge to properly tune it. To answer the question about the RCA setup the high level signal is ran from the hu to near the amp with speaker wire and then I have the kicker KISL converter that change the connection to RCA.

Thanks for all of the helpful advice and apologies for my ignorance on some of this stuff!

[philwsailz]

Are you using a KISL?????? Or a KISLOC????

Big difference. If a KISL your tower amp gains will end up being turned down almost all the way.

Phil
Kicker

[cpropes2005]

Initial setup and where I am back to now is a KISL and the amp set to high level inputs. I think the problem like you mentioned was mainly just that I had the gains set too high for use with the KISL. I do also have a KISLOC which I was experimenting with because I was thinking that maybe it would be better to convert to low level before entering the amp but as long as the noise is gone and I can still get decent volume with the gains all of the way down I will probably just stick with the KISL set up until I decide if I want to bite the bullet and install a line driver.

[philwsailz]

Consider this:
A cheap radio may only put out 1 or 2 volts of signal on the RCA pre-outs
A good head unit might put out 5 volts, but really they often only put out 2 or so.
A good line driver will bump voltage up, sometimes as high as 10 volts, (without adding any significant noise)
A pair of speaker wires each will often have the SAME voltage as a line driver, the difference being that the speaker outputs have the current required to drive a pair of speakers. The line driver, while operating at the same amplitude, lacks the current required to drive a speaker.

When we set the gains on any amplifier, we do so knowing the gain controls are not volume controls. Regardless gain setting, the amp will only deliver so much power; setting gains higher will not make the amp play louder. It only makes the amp get louder more quickly, as it responds to the input voltage.

The gain control works in the front end of the amp, and adjusts the amp's sensitivity. A high qain setting means high sensitivity; it "looks' for lower voltage signals to amplify... like the weak signal coming from the radio, AND all the noise that ends up on literally every piece of wire out there... The lower the radio's output voltage, the closer in amplitude it is to every other noise in the system. The amp makes all that stuff louder; radio signal AND noise.... When you have a higher signal voltage, your music signal is delivered to the amp at a much greater amplitude than the system noise. With more and more signal voltage, you can reduce the amp's sensitivity, and it will amplify less and less of the noise inherent in the system.

So...

With a low input voltage, (think lower quality head unit with 1-2V outputs) radio, you might have to set the amp gains at 12-o'clock, (as seen on a clock) or higher to get the amp to deliver max power when the radio is similarly turned up close to max.

With a higher-voltage radio you might only have to set the amp gains at 9 or 10-o'clock to get the same output

With a line driver or using speaker wires, the amplifier can be set with its gains even lower...

* The HIGHER the voltage, the greater difference in amplitude between the desired audio signal and the inherent system noise
* The HIGHER the voltage you can send to the amp, the lower you can set your gains.

This will be lost on people, but gains all the way down does not mean OFF. It only means the amp needs no increase in sensitivity to drive the amp to full power. This can be done with a good solid high-voltage signal; something you CAN get many times with a speaker-level input.

Bottom line: As the OP confirmed, the gains were simply set too high for use with a speaker level input.

FYI

Phil
Kicker

[cpropes2005]

Great info all around on this thread. Thanks guys for taking the time to help educate me and whoever else might read this.