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Speaker 'Hum'


Punyelroo

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Anyone experienced an issue with a relatively high pitched hum from the boat and tower speakers when the amps are on but no music is playing? It can get quite annoying so like to get rid of it ....

To me it does not seem to be alternator whine that a capacitor will fix, as it does not change pitch with rev's

Any thoughts gratefully accepted. 

Regards

Andrew

 

Edited by Punyelroo
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I had a similar situation with mine and got some great help troubleshooting.  Hopefully I can pass it on.  As I understand it, you can get signal noise from many sources.  Your specific setup will help us better determine the root cause.  Faulty RCA's, bad grounds or in my case, too much gain on the amp can cause additional sound inline.  For mine, I cranked up the zone controller gain and decreased the amplifier gain.  Can you describe your current setup?

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I had exact same thing.  I didn't notice it until I had the stereo on with the engine running.  I tried this before re-routing all my cables and after I confirmed everything was grounded well.

https://www.amazon.com/PAC-SNI-1-Noise-Isolator/dp/B000K50HJE/ref=sr_1_3?ie=UTF8&qid=1515071633&sr=8-3&keywords=rca+ground+loop+noise+isolator

Cheap and completely fixed the problem.  It probably masked the true issue....but who cares?  I am no longer embarrassed by the speaker hum.

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A noise can still be tied to the engine running and not vary with RPM. Its all about isolating the noise and narrowing down its path into the system. 

And yes, GLI's do mask the noise. Root issue still there and GFI's can effect the sound quality. Further, not all noise is a result of ground loop. 

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4 hours ago, goodmatt78 said:

I had exact same thing.  I didn't notice it until I had the stereo on with the engine running.  I tried this before re-routing all my cables and after I confirmed everything was grounded well.

https://www.amazon.com/PAC-SNI-1-Noise-Isolator/dp/B000K50HJE/ref=sr_1_3?ie=UTF8&qid=1515071633&sr=8-3&keywords=rca+ground+loop+noise+isolator

Cheap and completely fixed the problem.  It probably masked the true issue....but who cares?  I am no longer embarrassed by the speaker hum.

Where do you put that?  Between the HU and the amplifier?

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I put it between the amp and rca inputs....plugs right in and didn't even need to ground it.  I actually have one for each set of rca cables.

Edited by goodmatt78
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On 04/01/2018 at 11:39 PM, JeffK said:

I had a similar situation with mine and got some great help troubleshooting.  Hopefully I can pass it on.  As I understand it, you can get signal noise from many sources.  Your specific setup will help us better determine the root cause.  Faulty RCA's, bad grounds or in my case, too much gain on the amp can cause additional sound inline.  For mine, I cranked up the zone controller gain and decreased the amplifier gain.  Can you describe your current setup?

Thanks @JeffK. It's a little complex and maybe thats the root cause of the noise but in simple terms its 3 Rockford Amps (cant recall the specific models), 1 x Tower, 1 x Sub, 1 x Inboat's. All fed via a Wetsounds WS-420 Equaliser and the RFX5000 head unit (original)
All the RCA cables between the WS-420 and amps are of high quality but they do cross the boat from the WS-420 (driver side) to the Amps in the usual left hand side location so they are relatively long I guess. Amps are all powered from the original Malibu terminal blocks so presumably thats a good ground.

The hum is present on the Tower and Boat speakers but not the sub - presumably the frequency is way too high to hear it on the sub.

Perhaps I can isolate the amps from the WS-420 side and see it the hum is still present ...

Off to tinker but its 43C (~110F) here today so a little hot to fiddle around in the boat....!!!

Edited by Punyelroo
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On 04/01/2018 at 11:46 PM, goodmatt78 said:

I had exact same thing.  I didn't notice it until I had the stereo on with the engine running.  I tried this before re-routing all my cables and after I confirmed everything was grounded well.

https://www.amazon.com/PAC-SNI-1-Noise-Isolator/dp/B000K50HJE/ref=sr_1_3?ie=UTF8&qid=1515071633&sr=8-3&keywords=rca+ground+loop+noise+isolator

Cheap and completely fixed the problem.  It probably masked the true issue....but who cares?  I am no longer embarrassed by the speaker hum.

Thanks @goodmatt78. For $10 bucks it seems like its worth a try! Per @MLA it might not be the 'right' solution but I'm a bit like you - do I really care.....
I might get one and try it.

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If its in all of them id say its not an individual rca cable. (Unless a single cable from head unit to EQ) The more complex the system i.e equalizers, multiple amps ect. The harder to diagnose. Take out the eq and go from there. If noise goes then its in eq (its wiring, grounding etc) if not start at battery teminals and just eliminate one component at a time. 

I bought a car not long back (XE S-pac for any aussies on) the young guy had ground loop isolators in the system. I took them out re wired while lot and then didnt require isolators. They are now in the...

On 05/01/2018 at 10:55 AM, MLA said:

Spare parts bin :rofl:

 

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On 1/5/2018 at 4:39 PM, Punyelroo said:

Thanks @JeffK. It's a little complex and maybe thats the root cause of the noise but in simple terms its 3 Rockford Amps (cant recall the specific models), 1 x Tower, 1 x Sub, 1 x Inboat's. All fed via a Wetsounds WS-420 Equaliser and the RFX5000 head unit (original)
All the RCA cables between the WS-420 and amps are of high quality but they do cross the boat from the WS-420 (driver side) to the Amps in the usual left hand side location so they are relatively long I guess. Amps are all powered from the original Malibu terminal blocks so presumably thats a good ground.

The hum is present on the Tower and Boat speakers but not the sub - presumably the frequency is way too high to hear it on the sub.

Perhaps I can isolate the amps from the WS-420 side and see it the hum is still present ...

Off to tinker but its 43C (~110F) here today so a little hot to fiddle around in the boat....!!!

I'm going to walk you through the same help I got.  What are the gains on the amps set at for the tower and cabin speakers?  I ended up taking my 420 apart, increasing the gains there and decreasing the gains at the amp.  Problem solved.  I had gone through the effort of trying a new zone controller (had another one here), ran all new power wires for everything, new RCA's, etc.

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9 hours ago, JeffK said:

 

I'm going to walk you through the same help I got.  What are the gains on the amps set at for the tower and cabin speakers?  I ended up taking my 420 apart, increasing the gains there and decreasing the gains at the amp.  Problem solved.  I had gone through the effort of trying a new zone controller (had another one here), ran all new power wires for everything, new RCA's, etc.

OK @JeffK - will look into it. Appreciate the feedback. As the boat lives remote from me it might be a week or two before I get a look. I didn't get a chance to tinker the other day.

 

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