Stereo noise with new ground

[Jaylex]

Hey Captains,

I finally got around to getting my push button start installed over the weekend and while it was at the shop I had a few other things done, such as a new 3 bank charger, some more lights, DVSR mod, and to have the ground to the HU replaced.

He used a 10 guage ground from the HU to the Battery and it still has noise....I cant recall where on here I read about other things that could cause some interference but need some input Asap since its still the shop and prefer it get done this time there.

Any ideas or suggestions are welcomed!!

Most of my mods are in my sig

Thanks in advance!

 

[Seadeals]

Is your amp on that same ground?

 

[Jaylex]

I am not sure....i have 2 house batteries, whats the best option to reduce the chance for noise?

 

[swatski]

Need common ground for the HU and the amps!
This:

Have you cut the ground lead in the headunit harness and connected the ground from the headunit to the 0awg ground block? This is what I mean by the same path. It does make a big difference and is what fixed the same issue for others.

I followed your advice this weekend and walla, noise is gone. Ugh! Only if I had this little piece of knowledge, I would save few hours of my own work and the half day off and $250 paid to authorized JL installer that ended up messing with the gain to lower the buzz.... Better late than never.

Thank you!

 

[Mainah]

What kind of noise? Low grade constant hissing? Engine whine? Electronic buzzing? High pitched fast telegraph sounding?

Where are your amps? Are you using bluetooth? What happens when you turn off all leds in the boat?

 

[Meetball]

Common grounds and shielded rca connectors............

 

[Jaylex]

Like a low white noise,.doesnt whine, just sounds like low static. I have all 4 amps under the helm behind the connext.

I just confirmed and HU is grounded to same battery as amps.

He confimed the RCAs are shielded

I do use bluetooth only, and still hear it when all lights are off

What kind of noise? Low grade constant hissing? Engine whine? Electronic buzzing? High pitched fast telegraph sounding?

Where are your amps? Are you using bluetooth? What happens when you turn off all leds in the boat?

 

[Meetball]

Are you running any line converters or equalizers? I would start with removing rca cable to see if its amp internal or signal input, it could be something that is being produced by the head unit.

 

[Jaylex]

No line converters and no eqs, just the JL equipment...was really hoping this would do the trick.

I can have him play with the RCAs but beyond that still open to ideas

 

[Meetball]

Can you get to the back of your head unit easy? I would just unplug from there and see if the noise stops. if it does then its from source and or head unit.

 

[Meetball]

you could also try an aux cord to see if the Bluetooth is giving you your issue. Is it built into the head unit? Or are you using a standalone receiver?

 

[Mainah]

To be clear on my ground recommendations the same path to ground is what I recommend. The same path to ground is a common ground but a common ground is not always the same path to ground. A separate and dedicated common ground for part of a stereo system can still cause ground loops or impedance differential. Grounding the headunit to the same grounding block as the amps is what I recommend.

Amps will produce white noise when playback is paused or on Bluetooth when master volume is very low. This is normal and will seem worse on high power channels. If the white noise is evident when the music is playing I would double check the amp input switches to ensure set correctly and cover the unused rca inputs with rubber rca covers. Try muting the headunit to see what effect it has on the white noise. Try turning the blower on and off to see what effect that has too.

 

[ralphsmithiii]

Long shot, but did you do any adjustments to the amps during this time, specifically, adjust the gains? I'm wondering if your gain are too high and that's what you're hearing. If you didn't have that before and haven't touched the gains then it's most likely not your issue.

 

[tadmcmichael]

Looking for some help from some of you stereo gurus. I have a new to me boat and the factory and aftermarket stereo were a mess. I installed new subs, speakers, and amp when I got the boat. After installing my amp and tower speakers I noticed a whine through the towers. I have Rev 10s and two subs being powered by a WS Syn DX-6. I saw the thread about running a new ground to the head unit, so I first ran a new wire into the ground at the amp. That didn't help, so then pulled up the floor and ran a new ground for the head unit along the same path as the amp ground. Still the same whine. I thought maybe it was a ground loop issue, but I noticed the same whine through the boat speakers when the volume is high (90%.) I had been keeping the volume at 90% and using the iPhone to adjust volume up or down from there.

I took it a step further and disconnected the power, ground, and RCAs from the amp and still hear the bit of whine from the speakers powered by the head unit. It is slight, but once amplified it is quite annoying through the towers. It's the same noise when the engines are off, no blowers on, etc. To compensate, I turned the gain down on the towers to about 60% from the 80% where it was before. As long as I keep the volume lower on the head unit, the whine is manageable now through the towers. However, I want to make sure that I'm not leaving any stone unturned. Is this normal for the Polk P4A? Could something else be causing a problem on the boat? Bluetooth? Depth buzzer? Maybe I'm unrealistic about the amount of whine that the factory head unit is pushing to the amp through the RCAs? Would something like the following help?

https://www.bestbuy.com/site/metra-ground-loop-isolator-black/9855136.p?skuId=9855136

 

[Mainah]

Looking for some help from some of you stereo gurus. I have a new to me boat and the factory and aftermarket stereo were a mess. I installed new subs, speakers, and amp when I got the boat. After installing my amp and tower speakers I noticed a whine through the towers. I have Rev 10s and two subs being powered by a WS Syn DX-6. I saw the thread about running a new ground to the head unit, so I first ran a new wire into the ground at the amp. That didn't help, so then pulled up the floor and ran a new ground for the head unit along the same path as the amp ground. Still the same whine. I thought maybe it was a ground loop issue, but I noticed the same whine through the boat speakers when the volume is high (90%.) I had been keeping the volume at 90% and using the iPhone to adjust volume up or down from there.

I took it a step further and disconnected the power, ground, and RCAs from the amp and still hear the bit of whine from the speakers powered by the head unit. It is slight, but once amplified it is quite annoying through the towers. It's the same noise when the engines are off, no blowers on, etc. To compensate, I turned the gain down on the towers to about 60% from the 80% where it was before. As long as I keep the volume lower on the head unit, the whine is manageable now through the towers. However, I want to make sure that I'm not leaving any stone unturned. Is this normal for the Polk P4A? Could something else be causing a problem on the boat? Bluetooth? Depth buzzer? Maybe I'm unrealistic about the amount of whine that the factory head unit is pushing to the amp through the RCAs? Would something like the following help?

https://www.bestbuy.com/site/metra-ground-loop-isolator-black/9855136.p?skuId=9855136

A common path to ground has to be on the same wire as opposed two wires following the same path (two wires may even create a loop). The headunit, amp, and any control device like a dsp or eq should all be on the same main ground wire to the house battery with minimal distance branches to each device. Noise can also be introduced by other things like leds (speaker, courtesy, ambience), motors (blower motors as an example), or even a bad component (I got a bad dsp at one point and swapped it with another). Ground loop isolators just remove the noise by trying to filter it out and do not really remedy what is causing the issue. I have a bunch of electronics on my boat and no emi noise; so it is possible to eliminate.

 

[Julian]

Looking for some help from some of you stereo gurus. I have a new to me boat and the factory and aftermarket stereo were a mess. I installed new subs, speakers, and amp when I got the boat. After installing my amp and tower speakers I noticed a whine through the towers. I have Rev 10s and two subs being powered by a WS Syn DX-6. I saw the thread about running a new ground to the head unit, so I first ran a new wire into the ground at the amp. That didn't help, so then pulled up the floor and ran a new ground for the head unit along the same path as the amp ground. Still the same whine. I thought maybe it was a ground loop issue, but I noticed the same whine through the boat speakers when the volume is high (90%.) I had been keeping the volume at 90% and using the iPhone to adjust volume up or down from there.

I took it a step further and disconnected the power, ground, and RCAs from the amp and still hear the bit of whine from the speakers powered by the head unit. It is slight, but once amplified it is quite annoying through the towers. It's the same noise when the engines are off, no blowers on, etc. To compensate, I turned the gain down on the towers to about 60% from the 80% where it was before. As long as I keep the volume lower on the head unit, the whine is manageable now through the towers. However, I want to make sure that I'm not leaving any stone unturned. Is this normal for the Polk P4A? Could something else be causing a problem on the boat? Bluetooth? Depth buzzer? Maybe I'm unrealistic about the amount of whine that the factory head unit is pushing to the amp through the RCAs? Would something like the following help?

https://www.bestbuy.com/site/metra-ground-loop-isolator-black/9855136.p?skuId=9855136

If it makes you feel any better, I have exactly the same issue on my boat. Bugs the crap out of me. My solutions thus far....start the boat, or turn up the music! LOL

I also have a strange issue with the starboard side bow speaker....it keeps blowing. Can being wired wrong (wrong polarity) blow a speaker?

 

[Mainah]

If it makes you feel any better, I have exactly the same issue on my boat. Bugs the crap out of me. My solutions thus far....start the boat, or turn up the music! LOL

I also have a strange issue with the starboard side bow speaker....it keeps blowing. Can being wired wrong (wrong polarity) blow a speaker?

A speaker being wired out of polarity will just make it out of 180 degrees out of phase with the sound reproduction. It is more likely that the speaker is getting direct current somehow or there is a short in the wiring. I would try running new 14 awg wire to it.

I have been on quite a few 15-17 240/242/242x that have the noise issue. The ground for the PA4A on these models is not dedicated to audio equipment (other stuff like courtesy lights on the sub branch which is off a bigger branch off a trunk/bus connection). It appears to me the main consideration it all of the wiring was location rather than what kind of item would be on the branch. Running a common audio ground on a stock 16/17 242x should be rather easy with everything in the battery compartment. A short piece of 4awg from the house battery to a bus bar on the amp wall and running the ground for the amps and pa4a should do it. Perhaps even direct connections from all of them to the house negative battery post.

Another thing to check is rca cables. Rca cables are better when shielded.

 

[Julian]

A speaker being wired out of polarity will just make it out of 180 degrees out of phase with the sound reproduction. It is more likely that the speaker is getting direct current somehow or there is a short in the wiring. I would try running new 14 awg wire to it.

I have been on quite a few 15-17 240/242/242x that have the noise issue. The ground for the PA4A on these models is not dedicated to audio equipment (other stuff like courtesy lights on the sub branch which is off a bigger branch off a trunk/bus connection). It appears to me the main consideration it all of the wiring was location rather than what kind of item would be on the branch. Running a common audio ground on a stock 16/17 242x should be rather easy with everything in the battery compartment. A short piece of 4awg from the house battery to a bus bar on the amp wall and running the ground for the amps and pa4a should do it. Perhaps even direct connections from all of them to the house negative battery post.

Another thing to check is rca cables. Rca cables are better when shielded.

I have a negative bus bar in the battery compartment already. Guess I just need to stand on my head for a while figuring out which are the ground wires and run some new ones.

@Mainah is there a way (using an All Sun EM830 digital multimeter) to determine if that speaker is getting a short....or just easier to pull a new wire to it?

 

[tadmcmichael]

Thanks for the help guys.

I’m still getting the noise even when the amp is disconnected from everything (including Battery and RCAs) and the P4A has a 10 gauge ground directly to the house battery. The three different grounding locations I have tried for the head unit all have the same whine. I think I’m just expecting too much from the stock P4A. Would it help to ground the chassis for the head unit? Is there a different head unit I could install that would have cleaner pre-outs? Would it connect to the stock wiring harness?

 

[Mainah]

Thanks for the help guys.

I’m still getting the noise even when the amp is disconnected from everything (including Battery and RCAs) and the P4A has a 10 gauge ground directly to the house battery. The three different grounding locations I have tried for the head unit all have the same whine. I think I’m just expecting too much from the stock P4A. Would it help to ground the chassis for the head unit? Is there a different head unit I could install that would have cleaner pre-outs? Would it connect to the stock wiring harness?

Hmmm. Does it do this with the engines off?