# Constant static coming from front speakers



## ceapy (May 24, 2018)

Hello Everyone! 

I recently routed new front speaker wires and RCAs (Speakers are Infinity Kappa 62.11i), amplifier (Pioneer GM d9605), and 2 subs into my vehicle (2001 Saturn SC1). My Head Unit is a Kenwood DDX24BT. Rear speakers were not touched so they just wire back into the HU rather than the amp.

The amp and sub are located in the trunk. Power cable for the amp is routed through the left side of vehicle with the RCA (shielded) and speaker wires being routed through the right side of vehicle (Made sure to keep the power and signal wires seperate). Ground for the amp is attached to a metal frame in the trunk, made sure to sand the paint off and expose bare metal and was screwed and bolted down (measured at 0.0008 ohm at 2ma).

Something to note, last year I had a cheap sup and amp installed and it crapped out 6 months in during the cold winter. The front speakers (which were the Infinities) still had the OEM wires and were connected to the wire harness into my Kenwood HU. During that time there was no static or interference whatsoever. 

Now for the issues. 

There is a constant static sound when only having the vehicle running on the battery. Static remains constant even at 0 volume and when increasing volume to as high as I can bear with music playing. This static only comes from the front speakers, subs have no interference as far as I can tell when holding my ears right next to them. 

When turning on the vehicle, static becomes way worse and almost resembles a whirring sound. Revving the engine does not worsen the static. However, turning on the windshield wipers and the fans (car does not have an AC unit) at full blast does worsen the interference. Turning on the night/head lights does worsen the interference as well. 

I have a few ideas of what to test for, but would really appreciate opinions from people who have had more experience in this as it is my first time doing this.


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## minbari (Mar 3, 2011)

it sounds like you have the gains set too high. where as they set?


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## ceapy (May 24, 2018)

minbari said:


> it sounds like you have the gains set too high. where as they set?


After reading your post, I set them as low as they can go (no music or static was heard of course). Slowly increasing the gain, the static was immediately noticeable along with the music.


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## minbari (Mar 3, 2011)

ceapy said:


> After reading your post, I set them as low as they can go (no music or static was heard of course). Slowly increasing the gain, the static was immediately noticeable along with the music.


ok, so gains are prolly ok then.

pull the RCAs off the amplifier. Does the noise go away?

if you connect and MP3 player or phone in the amplifier RCA inputs directly, does the noise come back?


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## mattkim1337 (Jan 31, 2018)

ceapy said:


> static becomes way worse and almost resembles a whirring sound


This sounds like a ground loop caused by a voltage difference between your headunit and amplifier. I had a whining problem for a long time a few months ago and I fixed it by grounding my head unit to a bare metal factory bolt in the dash and relocating my amp ground to a factory grounding location. I would try moving the amp ground around.


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## minbari (Mar 3, 2011)

mattkim1337 said:


> This sounds like a ground loop caused by a voltage difference between your headunit and amplifier. I had a whining problem for a long time a few months ago and I fixed it by grounding my head unit to a bare metal factory bolt in the dash and relocating my amp ground to a factory grounding location. I would try moving the amp ground around.


it could be a little bit of that, but he has loud hissing when the engine is off too. I am guessing that if he solves the hissing, the whining will go away too.


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## asianinvasion21 (Sep 24, 2012)

minbari said:


> ok, so gains are prolly ok then.
> 
> pull the RCAs off the amplifier. Does the noise go away?
> 
> if you connect and MP3 player or phone in the amplifier RCA inputs directly, does the noise come back?


^^^ Try running something directly into the amplifier. Its always good to start there and then work your way forward.


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## ceapy (May 24, 2018)

mattkim1337 said:


> This sounds like a ground loop caused by a voltage difference between your headunit and amplifier. I had a whining problem for a long time a few months ago and I fixed it by grounding my head unit to a bare metal factory bolt in the dash and relocating my amp ground to a factory grounding location. I would try moving the amp ground around.


I could try it. But the amplifier I had last year was grounded in the exact same spot and there was no interference whatsoever. 

This was also back when my speaker wires were OEM and went straight to the wire harness into my HU, as opposed to now where the speaker wires are fed to the right side of the vehicle into the trunk. Would a voltage ground difference really be the cause? 



minbari said:


> ok, so gains are prolly ok then.
> 
> pull the RCAs off the amplifier. Does the noise go away?
> 
> if you connect and MP3 player or phone in the amplifier RCA inputs directly, does the noise come back?


Pulling out the RCAs from the amplifier (still connected to the HU) cuts out the static/noise and music does not come out of the front speakers either.

I pulled the RCAs out of the HU (still connected on the amp side) and there was still a static sound coming from the front speakers (nothing was connected to the RCAs on the HU side). I'm not able to connect my phone to the RCAs on the HU side because there's a lip on the connectors.


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## minbari (Mar 3, 2011)

ceapy said:


> Pulling out the RCAs from the amplifier (still connected to the HU) cuts out the static/noise and music does not come out of the front speakers either.
> 
> I pulled the RCAs out of the HU (still connected on the amp side) and there was still a static sound coming from the front speakers (nothing was connected to the RCAs on the HU side). I'm not able to connect my phone to the RCAs on the HU side because there's a lip on the connectors.


Ok. You need to re-run either your power or. RCAs to the back. Since the noise goes away with nothing connected and is still there with no HU connection.(but unplugged) you have what is called EMI noise. (Electro-magnetic induced) noise on the power line is being picked up by the RCAs

Sent from my LG-LS998 using Tapatalk


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## ceapy (May 24, 2018)

minbari said:


> Ok. You need to re-run either your power or. RCAs to the back. Since the noise goes away with nothing connected and is still there with no HU connection.(but unplugged) you have what is called EMI noise. (Electro-magnetic induced) noise on the power line is being picked up by the RCAs
> 
> Sent from my LG-LS998 using Tapatalk


Hm, that's unfortunate I'm not sure if I'll be able to reroute them as the power is as far into the left of vehicle as possible. The RCAs and speaker cables are as far to the right as I could make them. Not to mention the RCAs are shielded as well so it's surprising that there's be EMI noise present. I was thinking there was EMI noise affecting the speaker wires as they have no shielding.


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## minbari (Mar 3, 2011)

ceapy said:


> Hm, that's unfortunate I'm not sure if I'll be able to reroute them as the power is as far into the left of vehicle as possible. The RCAs and speaker cables are as far to the right as I could make them. Not to mention the RCAs are shielded as well so it's surprising that there's be EMI noise present. I was thinking there was EMI noise affecting the speaker wires as they have no shielding.


All I can say is reroute the RCAs. Maybe down the middle? It is picking up noise somewhere.

If you pull the RCAs off the hu and then pull them out from the dash? Maybe the noise is in the dash

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## ceapy (May 24, 2018)

minbari said:


> All I can say is reroute the RCAs. Maybe down the middle? It is picking up noise somewhere.
> 
> If you pull the RCAs off the hu and then pull them out from the dash? Maybe the noise is in the dash
> 
> Sent from my LG-LS998 using Tapatalk


Alright thank you for the advice! I'll try rerouting the RCAs down the middle tomorrow, I'll let you know if it gets rid of the noise. 

If rerouting doesn't work I'll probably just hook it back to the OEM wiring and have the speakers wired to the HU

Edit: Tomorrow I'll purchase a RCA to AUX cable and connect my phone from the trunk to confirm if it's the RCA that's being run through the length of the vehicle that's picking up the EMI. If there's no static heard, I'll purchase better quality RCAs to hopefully keep the EMI out as well as testing different routing locations to hopefully keep the interference out of the signal.


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## minbari (Mar 3, 2011)

If noise goes away when you pull the RCAs off the amp, engine off. Then it is picking it up on the RCAs. Might take a few tries, but you will get it

Sent from my LG-LS998 using Tapatalk


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## ceapy (May 24, 2018)

minbari said:


> If noise goes away when you pull the RCAs off the amp, engine off. Then it is picking it up on the RCAs. Might take a few tries, but you will get it
> 
> Sent from my LG-LS998 using Tapatalk


Hooked up a RCA to AUX into the amplifier and my phone. No static whatsoever from front speakers when playing music. 

Static is definitely being introduced via RCA cables. I ended up purchasing high quality triple shielded RCA cables and routed the cables from the HU, out the window and to the trunk. There was still static. 

After talking with staff at visions, they said it's probably the pre outs from the HU. They're rated at 2.5V whereas if I had 4V preouts there would likely be a lot less interference. 

I've decided to reconnect the OEM wires straight back to the HU and just have the subs connected to the amp. Maybe in the future i'll invest in a higher quality HU and then rewire the speaker wires and RCA into the amp. 

Thanks for all your help.


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## asianinvasion21 (Sep 24, 2012)

ceapy said:


> Hooked up a RCA to AUX into the amplifier and my phone. No static whatsoever from front speakers when playing music.
> 
> Static is definitely being introduced via RCA cables. I ended up purchasing high quality triple shielded RCA cables and routed the cables from the HU, out the window and to the trunk. There was still static.
> 
> ...


Did you try connecting the aux to the RCA's behind the head unit? That can at least tell you if the noise is being picked up through the RCA's.


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## minbari (Mar 3, 2011)

That is a bummer. But it does appear to be the hu

Edit: you did say rye noise was still there with the RCAs pulled off at the HU, right? If that is the case. The noise is being induced from something in the dash. Not sure how to fox that

Sent from my LG-LS998 using Tapatalk


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## ceapy (May 24, 2018)

minbari said:


> That is a bummer. But it does appear to be the hu
> 
> Edit: you did say rye noise was still there with the RCAs pulled off at the HU, right? If that is the case. The noise is being induced from something in the dash. Not sure how to fox that
> 
> Sent from my LG-LS998 using Tapatalk


Yep, that is the case. Most likely the HU preouts from what the guys at Vision were saying. 

I have another issue now and going to try fixing it in a few hours. So after cutting my new speaker wires and routing them back into my HU wiring harness (front speakers are static free, yay!), my subs now have constant static and make a thumping sound when turning on my night lights and windshield wipers. 

It's really odd, because prior to any of this there was no static/thumping sound present in the subs.

Any suggestions are appreciated so I have an idea of what to test out first. And pulling out the RCAs from HU eliminates the static as well (different from the front speakers as they would produce static with the RCAs pulled out from the HU side).


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## SPLEclipse (Aug 17, 2012)

You need to move the ground for your headunit to somewhere else, like mattkim said. Factory wiring typically uses "star" grounding points where a bunch of components are grounded in the same spot. This works fine when you are just using the headunit to power speakers, but once you add a secondary ground to the signal chain (the amp ground) you can create a ground loop. The slight fluctuation in potential between the amp and headunit when other components connected to the same ground point are activated (wipers, signals, a/c, etc) causes the anomalies.

You can test this by running a long wire to the back of the car and grounding the headunit to the same point where the amp is grounded.


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