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Hate to repeat the preceding post, however it's a bit different of a problem. Same overpowering annoying sound coming from the XM9s. See boat and audio description in my signature. When the engine is not running, system sounds great. Crank the boat, terrible whine coming from tower speakers only. I can turn them all the way down, DC the RCA cables, the whine is still there. Only way to get it to stop is if I pull the fuse on the Exile amp.
Brian, if you read this, can you chime in also?
How many batteries are you running?
It's odd that you have noise in just one zone. Are you absolutely positive that the noise is exclusive to the tower speakers? Have you increased the input gain on two channels of the in-boat amplifier and placed your ear up against the in-boat coaxials to verify this zone is really noise free? Keep in mind that an HLCD tower speaker has an extremely sensitive horn loaded tweeter that often has ten times more acoustic power (+ 10 dB) as compared to the in-boat coaxials.
I suspect that you have thorough read the other threads about ALL audio power going to the same physical point and the same scheme with the ground. Once you've determined you have noise there can be no exceptions. Also, you cannot have alternate audio components connected to separate batteries.
Noise induced via RCA cable proximity is extremely rare if the RCAs are decent quality and correctly terminated and seated. Are you using the same RCA cables following the same path? You can always try a substitute RCA cable run on the outside and away from any noise radiated power cables or electrical components.
Have you tried reversing the HU RCA outputs so that the opposite RCA pair runs the tower amplifier? Btw, never unplug or plug-in RCAs while your audio system is powered up.
I would also disconnect one tower speaker at a time and test with just one playing. Any frayed and shorted wire in the speaker harness, even a single fine strand, can induce noise into the entire signal path of that amplifier.
You can also temporarily substitute one channel of your Kicker amplifier to the tower harness to see if the noise is exclusive to the tower amplifier.
Where is the input gain setting on your tower amplifier?
Try shorting the amplifier input and check to see if you have noise. Then try shorting the RCA cable input at the HU end and check if you have noise.
None of these steps are random. All are designed to isolate potential causes of the noise. Once you get any change in status you can narrow your focus to that area.
Do you have a multimeter? If so there are a few measurements that could provide a far quicker and less labor intensive diagnosis.
I have this same issue and I'd love to be able to diagnose with a multimeter.Quote:
Originally Posted by David Analog
Any knowledge you can provide would be GREAT! I'd like to avoid being trapped under the dash for a half day.
OutbackV2008,
Do you have the identical situation as Jeff with the noise in only one zone?
Is the noise high-pitched alternator whine, only with the engine running, changes with RPM, always at the same level regardless of the volume level?
Is the HU a Kenwood?
Have you removed the HU power & ground wiring entirely from the factory harness and redirected those connections at the same point as the amplifiers' primary terminals?
Is ALL, 100%, of the audio equipment getting power and ground from the same supply/battery/etc. ?
Running two batteries Woody. I will try to look at some of the mentioned stuff tomorrow and report back.
Hey Mr. Analog,
I do not have the zone controller installed yet but I intend to do it once I resolve my noise concerns. The zone controller is the dual zone ws-420. The alternator/whatever whine is more prominent in the towers than the boat. Towers are wet sounds 10" hlcd's but boat are factory.
The head unit is a Kenwood and uses the factory harness. In ignorance, that was intentional on my part.
From the sounds of it I need to re-route the ground and the power to the same location as the amplifiers as a preliminary investigation. Having said that, I would like to continue using the factory switch.
Can I reroute the ground and the power from the head unit without disturbing the switch wiring? From your post above it sounds like I only need to shift the yellow (because I fact the yellow carries the power load not the red) and the ground to match the amps and I'll be good.
Any help would be much appreciated.
Sent from my iPhone using Tapatalk
OutbackV2008,
All correct. It's pointless for me to explain a bunch of steps, the whys and the logic, when we already know the answer.
The source electronics must come off the factory harness and share a respective (separate + & -), common point with ALL other audio components in the audio path. You can use an interrupt relay off the key or switch so that you can maintain the keyed or switched function but circumvent the key or switch power.
It's normal for the tower HLCD speakers to have a greater noise level because they are 10 times more sensitive in acoustic terms.
Outback,
You may not need to reroute the head-units yellow B+ and black GND, but you absolutely need to make sure they share the same battery source as the amps and any other audio gear. If the ACR system was added after the fact, you could have easily split those sources up between the new house battery and the original battery that is now the cranking. So trace out the harness and see where things go. Given what described in your posts, I do suspect that the audio gear is drawing from both batteries, not the new house battery solely.
Alright, here's how I'm powered up. Everything is coming from the same power source correct?
Attachment 20517Attachment 20518Attachment 20519Attachment 20520Attachment 20521
Jeff,
I re-read your OP. Did you indicate that you still have noise on the tower speakers with the input RCAs of the tower amplifier disconnected at the amplifier end?
Yes David that is correct.
Okay, I originally overlooked that because of the 'DC' abbreviation.
Open RCAs can still pick up noise. So use 1/2 a short RCA cable to short the left input to the right input and try again with the gain at no more than 60%. You should be noise free. Let's assume you still have noise.
1) Triple check that amplifier ground.
2) Disconnect both outputs. Use a 2-conductor wire to test a substitute speaker (any 'other' speaker) laying on the floor. If you have noise then send back the amplifier. If the noise disappears then the issue is with a) the tower harness, or b) one or both of the speakers.
3) So next isolate an existing tower speaker by using a new harness wire. If the noise disappears you likely have a wire strand touching something it shouldn't in the tower. Test the tower for voltage with the tower system playing. The presence of voltage would indicate a wire to tower short. Also test the tower for continuity incase it is grounded. The tower should be totally neutral in both cases (pos. and neg.).
3) If the noise is still there then isolate one tower speaker at a time. It's unlikely but a crossover inductor that is open at one end could become an antenna for EMI or RFI.
4) Temporarily change the physical location of the tower amplifier in case it is too close to a strong electromagnetic field, like a battery for example.