Whine through speakers

[sscott0203]

I know this has been covered countless times, but I think I have the wiring correct based on all the posts I've read, however I still have the whine even with all amps at their lowest gain settings. Not sure where where to start. Any help much appreciated. Here is my wiring diagram with my current setup

https://uploads.tapatalk-cdn.com/20170414/2e48055e3d8fcead07d7b123c33a128b.jpg

[MLA]

So its audible from all the speakers? Likely not audible from the sub though.

[sscott0203]

Correct. Tower and cabin speakers, its difficult to hear from the sub so can't say for sure but assuming it's throughout the system.


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[MLA]

Ok, so we know its likely upstream of the amps and not an amp/speaker issue or a single RCA. What kind of distance wiring wise, is it between the head unit and battery/remote B+ stud and head -unit and amp distribution block? Are the tower and in-boat speaker amp different brands?

[sscott0203]

Normal distance for a typical moomba amp rack setup.
Kenwood 4 channel powering kicker cabin speakers.
Orion amp powering Orion sub
Wetsounds HT-4 powering a pair of rev8's.

https://uploads.tapatalk-cdn.com/20170415/db52fc78f027bdb76fcc0ab59beb7174.jpg

https://uploads.tapatalk-cdn.com/20170415/2df50d6656027e1575f48bf5e131586b.jpg

https://uploads.tapatalk-cdn.com/20170415/ce24093ede75648a381efb4602198d04.jpg

https://uploads.tapatalk-cdn.com/20170415/f4d624eb35a83aa04ee020a8ff991415.jpg

Does the grounding point look normal here with the nut behind the main ground cable?


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[sscott0203]

Ok, so we know its likely upstream of the amps and not an amp/speaker issue or a single RCA. What kind of distance wiring wise, is it between the head unit and battery/remote B+ stud and head -unit and amp distribution block? Are the tower and in-boat speaker amp different brands?

Each run 2-3 feet max.


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[sscott0203]

Currently out on the water troubleshooting my issues. Obviously not an RCA issues as I'm getting noise through all speakers/3 amps, or at least you wouldn't think.

Unplugged all RCAs at amps, very slight static through tower speakers when putting ear up to speaker. Plugged RCAs back in to amps and unplugged from HU, no noise whatsoever.

Any ideas based off that?

Attempt 1- I tried taking the HU ground (which is already grounded to the battery) and grounding it to the metal on the HU along with the battery. Noise still present.

Attempt 2- removed 2nd battery completely. Noise reduced but still present.

Searching and thinking about what to try next. If anyone has any ideas, please share.



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[sscott0203]

Looking into the main ground now.
Every car audio install I've ever done or read about, the paint should be sanded off the ground location.

https://uploads.tapatalk-cdn.com/20170420/665d09b241c096cf93ba4d5b7788b0c2.jpg

Not the case here, but since this is a threaded stud going into the block, maybe the threaded stud is getting grounded from the inside of the block and not being grounded on the little bracket you see.


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[sscott0203]

Looking into the main ground now.
Every car audio install I've ever done or read about, the paint should be sanded off the ground location.

https://uploads.tapatalk-cdn.com/20170420/665d09b241c096cf93ba4d5b7788b0c2.jpg

Not the case here, but since this is a threaded stud going into the block, maybe the threaded stud is getting grounded from the inside of the block and not being grounded on the little bracket you see.


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Scrapped the paint off, no difference, still annoying static/beeping/pulsing noise.


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[sscott0203]

Well.... I had accidentally grounded the HU twice. Ran straight to the battery but then had another wire running to the ground distribution block. Removed ground from battery and cut noise in half. In process of hooking 2nd battery back up.
Shm



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[trayson]

Well.... I had accidentally grounded the HU twice. Ran straight to the battery but then had another wire running to the ground distribution block. Removed ground from battery and cut noise in half. In process of hooking 2nd battery back up.
Shm



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I think you're on the right track. the stock head unit grounds are typcially crap. bypassing that by going straight to the battery is definitely the best bet.

[TrueKaotik]

Sorry very busy... engine whine or while sitting with no key on hiss?

[TrueKaotik]

Normal distance for a typical moomba amp rack setup.
Kenwood 4 channel powering kicker cabin speakers.
Orion amp powering Orion sub
Wetsounds HT-4 powering a pair of rev8's.

https://uploads.tapatalk-cdn.com/20170415/db52fc78f027bdb76fcc0ab59beb7174.jpg

https://uploads.tapatalk-cdn.com/20170415/2df50d6656027e1575f48bf5e131586b.jpg

https://uploads.tapatalk-cdn.com/20170415/ce24093ede75648a381efb4602198d04.jpg

https://uploads.tapatalk-cdn.com/20170415/f4d624eb35a83aa04ee020a8ff991415.jpg

Does the grounding point look normal here with the nut behind the main ground cable?


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Yes, normal on all.

[David Analog]

Seth,
Several of the results you mentioned are normal, or at least predictable. A live amplifier with an open RCA input can become an antenna for any airborne noise. When you close the open amplifier input with an RCA cable, you effectively move the antenna to the other end of the open RCA cable. That is why a conclusive test is usually done with a shorted input (simply a short jumper across the L & R inputs).
There should be only ONE physical ground source and ONE physical supply source. No exceptions. And the distribution blocks close to the amplifiers are probably the best reference for everything including all HU modes.
For the moment, simplify this diagnosis process so there is no chance of one issue masking another. One HU. One RCA. One amplifier. One wire and speaker. Find one configuration that is 100% free of boat-induced noise. Now you have a 'known'. Then when you add an element and noise reappears, you will have a narrow issue to focus on.
An issue worth verification, with all disconnected (main HU molex disconnected), the HU RCA ground should show 100% continuity to the HU chassis.
Rarely is a problem with the boat the true cause, as noise is a normal part of the electrical system, but on occasion there is a boat failure to blame. The engine block ground source is important, and so is the hidden terminations at both ends of that cable. You might include the factory ground for the helm buss as that is a normal shunt for boat component noise.
More to come after you check the above.

[sscott0203]

Sorry very busy... engine whine or while sitting with no key on hiss?


Engine noise, only while running.


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[sscott0203]

Seth,
Several of the results you mentioned are normal, or at least predictable. A live amplifier with an open RCA input can become an antenna for any airborne noise. When you close the open amplifier input with an RCA cable, you effectively move the antenna to the other end of the open RCA cable. That is why a conclusive test is usually done with a shorted input (simply a short jumper across the L & R inputs).
There should be only ONE physical ground source and ONE physical supply source. No exceptions. And the distribution blocks close to the amplifiers are probably the best reference for everything including all HU modes.
For the moment, simplify this diagnosis process so there is no chance of one issue masking another. One HU. One RCA. One amplifier. One wire and speaker. Find one configuration that is 100% free of boat-induced noise. Now you have a 'known'. Then when you add an element and noise reappears, you will have a narrow issue to focus on.
An issue worth verification, with all disconnected (main HU molex disconnected), the HU RCA ground should show 100% continuity to the HU chassis.
Rarely is a problem with the boat the true cause, as noise is a normal part of the electrical system, but on occasion there is a boat failure to blame. The engine block ground source is important, and so is the hidden terminations at both ends of that cable. You might include the factory ground for the helm buss as that is a normal shunt for boat component noise.
More to come after you check the above.

Thanks for the suggestions David. I will give it a try in the next week or so, not sure when I'll make it out to the boat next.

I definitely cut 80% of the noise out when I discovered I had somehow wired the HU ground to the battery and to the ground of the distribution block. Removed the ground wire going to the battery and kept the one running to the ground distribution block, huge improvement.

I still have a slight amount of noise, however it's not that noticeable unless you put your ear up to one of the rev8's, it's not noticeable at all through the cabin speakers.




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[David Analog]

That sounds like you are close, maybe close enough that properly set gains will take care of the rest.

[smorris7]

Thanks for the suggestions David. I will give it a try in the next week or so, not sure when I'll make it out to the boat next.

I definitely cut 80% of the noise out when I discovered I had somehow wired the HU ground to the battery and to the ground of the distribution block. Removed the ground wire going to the battery and kept the one running to the ground distribution block, huge improvement.

I still have a slight amount of noise, however it's not that noticeable unless you put your ear up to one of the rev8's, it's not noticeable at all through the cabin speakers.




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This now sounds like more of a gain issue on the tower amp.


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[David Analog]

This now sounds like more of a gain issue on the tower amp.


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I agree, and that may very well be the case here. On the flipside, an HLCD has a compression horn tweeter that is at least 10 dB more sensitive than the tweeters found in the in-boat coaxials, so they can expose a noise issue that can be traced back to the source when it may be inaudible in other speakers. A 10 dB difference equates to 10 X power.