# Ground loop noise



## Elgreco (Aug 28, 2017)

Hello. I have 2 amps in my system. One for mids+highs and 1 that drives my subs. I had a cheapie boss amp for the subs and never had issues out of it. I took it out and installed an infinity k1000 and changed nothing else. I get this annoying whine that changes with rpm now. Unplug RCA's from k1000 and it goes away. I just think it's weird that the ole boss amp had no noise and the infinity does? What do y'all think the best course of action is? If it helps I have a 80prs and my other amp is a zapco st-4x sq.


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## minbari (Mar 3, 2011)

always check the regular stuff. make sure all the grounds are common and tight. make sure all your speaker wires solid. try swapping RCAs, bad ground on those can cause noise.


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## Elgreco (Aug 28, 2017)

Well, I played with the grounds for the radio and the 2 amps. Made zero difference. Hooked up the old amp again, noise is completely gone. Maybe I just got a bad amp? Took a quick video.
https://youtu.be/3K1FCxRysoA


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## Locomotive Tech (May 23, 2016)

the question is, on the Boss, are the shields for the RCA's grounded to the amp ground? or not grounded at the amp end at all???


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## Elgreco (Aug 28, 2017)

Locomotive Tech said:


> the question is, on the Boss, are the shields for the RCA's grounded to the amp ground? or not grounded at the amp end at all???


This is the boss amp. https://www.bossaudio.com/product/c...-auto-monoblock-amplifier-boss-audio-ar3000d/


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## Locomotive Tech (May 23, 2016)

No to be a jerk, did you hot swap the amp?


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## Elgreco (Aug 28, 2017)

Locomotive Tech said:


> No to be a jerk, did you hot swap the amp?


I unhooked the power wire before I swapped it if that's what you mean?


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## gijoe (Mar 25, 2008)

Elgreco said:


> I unhooked the power wire before I swapped it if that's what you mean?


Have you ever disconnected the RCA's with the Pioneer head unit still on?


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## Elgreco (Aug 28, 2017)

gijoe said:


> Have you ever disconnected the RCA's with the Pioneer head unit still on?


I did after trying to figure out the noise, yes. Not when I installed it. Even after that it still doesn't make noise with the old amp in. Vehicle was off, main power wire disconnected before swapping amps initially.


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## Elgreco (Aug 28, 2017)

I ordered some audioquest Rca cables so I will give those a try and see what happens.


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## gijoe (Mar 25, 2008)

What do you mean you "played with the grounds?" Are both amps grounded to the same spot? Are they grounded to bare metal (no paint)? Where are they grounded (there are a lot of places in a car that look nice, but have a highly resistant path back to the battery)? A ground issues is much more likely than noise through RCA's. I suspect your new RCA's will prove a waste of money, and time (but, maybe not).

Since you think the new amp is the problem, try disconnecting the RCAs (with power off) and plug in a phone/ipod/DAP into it with a 3.5mm RCA cable. If the amp produces the music it should without noise, then the problem is before the amp. If the problem stays then you know it's not the head unit, or the RCA's.


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## WilliamS (Oct 1, 2016)

Sounds like the ground its sufficient on the amp. If pulling the RCAs eliminates the noise thats where I would double check to make sure its heavy and has good contact on both the amp side as well the chassis. 

Did you try those RCA on the other amp to see if the noise follows?


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## Elgreco (Aug 28, 2017)

The sub amp is grounded to clean bare metal in the trunk floor pan with a bolt, 2 big fender washers and a nut with dielectric grease to keep corrosions away. The mid/high amp is grounded at the seat base. Radio uses factory radio ground. Basically I grounded all 3 at the same seat base ground and nothing changed. My sub RCA's are a little raggedy so I figured it's worth a shot. Im skeptical that it will fix the issue. The mid/hi amp has brand new RCA's.


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## Elgreco (Aug 28, 2017)

My battery main body ground and both amp grounds are brand new 4 gauge OFC cable.


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## gijoe (Mar 25, 2008)

Elgreco said:


> The sub amp is grounded to clean bare metal in the trunk floor pan with a bolt, 2 big fender washers and a nut with dielectric grease to keep corrosions away. The mid/high amp is grounded at the seat base. Radio uses factory radio ground. Basically I grounded all 3 at the same seat base ground and nothing changed. My sub RCA's are a little raggedy so I figured it's worth a shot. Im skeptical that it will fix the issue. The mid/hi amp has brand new RCA's.


Do you have a decent DMM to measure the resistance of the ground? Seat bolts are often bad grounds, and the trunk pan could also be pretty bad. I'm not doubting your previous tests as much as I'm trying to prevent you from running new RCA's when that usually isn't the problem when you have alternator whine. The RCA's could be bad, and picking up noise, but it's more likely that the amps/head unit grounds need work. If you thing the RCA's are beat up, you may want to replace them anyway, so hopefully that ends up being the problem, otherwise you'll have to end up doing the troubleshooting that I recommended anyway.


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## Elgreco (Aug 28, 2017)

I have a fluke dmm and a Snap-on Zeus that has a built in scope. When I test the new rcas I'm not gonna tuck them in yet.


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## Elgreco (Aug 28, 2017)

I can do a voltage drop test on the ground side I guess. The car does not have to be running for the noise to happen. Also you can have the volume on zero and it will make the noise. If you turn the radio off where it just displays time/date the noise is not there. I think it cuts power to the remote wires if I do that.


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## SPLEclipse (Aug 17, 2012)

To my ear that doesn't sound like _typical_ ground loop noise. In the video (before I realized you were putting the mic near the speaker) it sounded almost like a whining capacitor or inductor.

It's possible there's an issue with the amp, and it might be worth it to try grounding the RCA shield to whatever reference ground you choose to see if there's an issue with the ground reference inside the amp.


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## Elgreco (Aug 28, 2017)

SPLEclipse said:


> To my ear that doesn't sound like _typical_ ground loop noise. In the video (before I realized you were putting the mic near the speaker) it sounded almost like a whining capacitor or inductor.
> 
> It's possible there's an issue with the amp, and it might be worth it to try grounding the RCA shield to whatever reference ground you choose to see if there's an issue with the ground reference inside the amp.


I'll give that a try.


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## gijoe (Mar 25, 2008)

SPLEclipse said:


> To my ear that doesn't sound like _typical_ ground loop noise. In the video (before I realized you were putting the mic near the speaker) it sounded almost like a whining capacitor or inductor.
> 
> It's possible there's an issue with the amp, and it might be worth it to try grounding the RCA shield to whatever reference ground you choose to see if there's an issue with the ground reference inside the amp.


I think you might be right on this. I must not have read carefully enough earlier, I though he was talking about alternator whine, but that noise sounds more like a broken amp.


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## Elgreco (Aug 28, 2017)

This is a high quality rendition of my setup.


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## Elgreco (Aug 28, 2017)

gijoe said:


> SPLEclipse said:
> 
> 
> > To my ear that doesn't sound like _typical_ ground loop noise. In the video (before I realized you were putting the mic near the speaker) it sounded almost like a whining capacitor or inductor.
> ...


The noise changes with revs BUT the car does not have to be running for the noise to happen.


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## gijoe (Mar 25, 2008)

All of your equipment should be grounded to the same point. Does the noise come from all speakers? Sometimes high frequency noise sounds like it's only coming from the tweeters, because of the frequency, but up the LPF on the mids and listen there too.


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## Elgreco (Aug 28, 2017)

I tried grounding all of them to the same point. You are correct that the noise sounds like it's mostly coming from tweeters. I just tried grounding the rca's on the amp with no difference


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## gijoe (Mar 25, 2008)

Elgreco said:


> I tried grounding all of them to the same point. You are correct that the noise sounds like it's mostly coming from tweeters. I just tried grounding the rca's on the amp with no difference


Yes, but if the "same point" was a ****ty point, it wouldn't have told you anything. Since you have a good meter, I'd measure the resistance from your intended ground to the battery. Just because it's metal doesn't mean there is a good electrical path to the battery. Modern cars are held together with glue, which makes finding a good ground a little more difficult.

Noise issues can be hell. You'll just need to start narrowing the problem down by ruling out what isn't the problem. Just like a car mechanic, start with the most logical, easiest, and cheapest fix. Swap out the amp and keep everything else the same, see if the problem goes away. If it does, then it seems pretty obvious the amp is at fault (unless simply messing with the connections in the process takes care of the issue).


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## Elgreco (Aug 28, 2017)

This car is an 87, not much glue but I understand what you are saying. Measuring resistance can mean very little sometimes. You need to do a load test. DVOM's send a miniscule amount of voltage out when checking resistance so it doesn't take much to show very little resistance. Either way I may have helped narrow down the problem. If I ground the RCA to the radio chassis, the noise for the most part disappears. I will upload a video.


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## Elgreco (Aug 28, 2017)

Listening to it the video, the sound is significantly lessened. And it doesn't not matter which rca I ground.
https://youtu.be/9Md4Zbb0LWY


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## gijoe (Mar 25, 2008)

Elgreco said:


> This car is an 87, not much glue but I understand what you are saying. Measuring resistance can mean very little sometimes. You need to do a load test. DVOM's send a miniscule amount of voltage out when checking resistance so it doesn't take much to show very little resistance. Either way I may have helped narrow down the problem. If I ground the RCA to the radio chassis, the noise for the most part disappears. I will upload a video.


That's why we asked about hot swapping the RCA's. Pioneer uses pico fuses on the RCA's and they are very sensitive to blowing if you hot swap.


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## Elgreco (Aug 28, 2017)

gijoe said:


> That's why we asked about hot swapping the RCA's. Pioneer uses pico fuses on the RCA's and they are very sensitive to blowing if you hot swap.


Yeah I did a little reading and found that. That's why I tried it. I don't remember hot swapping them prior to the noise though. Still very odd that the other amp doesn't make noise. Oh well.


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## gijoe (Mar 25, 2008)

Elgreco said:


> Yeah I did a little reading and found that. That's why I tried it. I don't remember hot swapping them prior to the noise though. Still very odd that the other amp doesn't make noise. Oh well.


Good luck, I hope you resolve it. I had pico fuse issues in my 800prs, grounding the RCA's helped, but never eliminated it completely (not sure why). Soldering a resistor across the blown fuse fixed it though.


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## Elgreco (Aug 28, 2017)

gijoe said:


> Elgreco said:
> 
> 
> > Yeah I did a little reading and found that. That's why I tried it. I don't remember hot swapping them prior to the noise though. Still very odd that the other amp doesn't make noise. Oh well.
> ...


I just measured the resistance between rca on the radio and chassis ground and I got about 1ohm. I don't think it's blown?


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## gumbeelee (Jan 3, 2011)

If I have read this post correctly and I did skim through it, I believe I would just switch amps to something elsr if the other amp eliminates the noise. Im sure u dont want to buy another amp, but sometimes that the easiest way to go


Sent from my iPhone using Tapatalk


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## Locomotive Tech (May 23, 2016)

I think it may be time to accept that the Infinity amp is in need of repair. Is it new? If the Boss sounds better why not leave it installed?


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## Elgreco (Aug 28, 2017)

The amp is brand new. I bought the infinity because I'm upgrading to a Dayton reference 12" HO and giving my current sub+amp to my cousin. I kinda stole it out of the car I sold him and told him I'd give it back when I did my taxes and got a new setup. It's just a pair of dual 12"s I got for free and that boss amp. If the new RCA's don't do it I will exchange it or get a different amp.


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## Locomotive Tech (May 23, 2016)

I think that should be the way to go, if you got from a reputable shop they should honor a warranty without question.


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## Elgreco (Aug 28, 2017)

Locomotive Tech said:


> I think that should be the way to go, if you got from a reputable shop they should honor a warranty without question.


Got it from crutchfield. I had already called them and he said try different rca's. Said if that don't do it we will rma it.


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## mitchell0715 (Apr 11, 2015)

Elgreco said:


> Got it from crutchfield. I had already called them and he said try different rca's. Said if that don't do it we will rma it.


If it's literally the amp (or so it seems) RMA it and get a different amp

Even a PPI 900.4 as much as people will bash on it  

Be sure your amp is causing the noise though, no point in wasting time swapping amps if you still have the problem


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## MikeS (May 23, 2015)

Elgreco said:


> Unplug RCA's from k1000 and it goes away. I just think it's weird that the ole boss amp had no noise and the infinity does?


The old boss amp probably has floating rca grounds, used to be very common even on cheap amps = no gnd loop noise. Now you get cheap china amps with rca grounds directly connected to GND on the amp. Measure it like already suggested from rca connector gnd to amp gnd, if you get 0 ohms return the amp and get something else.


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## Holmz (Jul 12, 2017)

MikeS said:


> The old boss amp probably has floating rca grounds, used to be very common even on cheap amps = no gnd loop noise. Now you get cheap china amps with rca grounds directly connected to GND on the amp. Measure it like already suggested from rca connector gnd to amp gnd, if you get 0 ohms return the amp and get something else.


Sounds (visually from the post) like the old may be better in sound and uin design?


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## MikeS (May 23, 2015)

Holmz said:


> Sounds (visually from the post) like the old may be better in sound and uin design?


All I can remember that boss was and is one of the cheapest.. not better sounding. There might be a good piece sometimes with unknown/cheap brands.


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## oleve (Feb 24, 2018)

interesting thread, I also have the same question


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## Holmz (Jul 12, 2017)

MikeS said:


> All I can remember that boss was and is one of the cheapest.. not better sounding. There might be a good piece sometimes with unknown/cheap brands.


Cheapest maybe, but if there is no noise, then one could argue it is better than the current one that hums and buzzes?

Ground loop problems are no fun.


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## minbari (Mar 3, 2011)

Elgreco said:


> The noise changes with revs BUT the car does not have to be running for the noise to happen.


that is not likely a group loop problem then. I have never had a ground loop that made noise with the engine off


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## Locomotive Tech (May 23, 2016)

I am wondering if the HU ground is weak and trying to seek ground back throught the RCA's to the amp?????


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## Holmz (Jul 12, 2017)

Locomotive Tech said:


> I am wondering if the HU ground is weak and trying to seek ground back throught the RCA's to the amp?????


One could make an RCA cable up where the ground is only compacted at one end.


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## minbari (Mar 3, 2011)

Locomotive Tech said:


> I am wondering if the HU ground is weak and trying to seek ground back throught the RCA's to the amp?????


every HU I have seen in the last 20 years have had a floating signal ground on RCAs. same at amplifier side.

I wont disagree that a poor ground at the HU can cause all kinds of noise though. the ground referance between your HU and all your downstream devices will have a difference of potential. this will cause noise.


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## Holmz (Jul 12, 2017)

minbari said:


> every HU I have seen in the last 20 years have had a floating signal ground on RCAs. same at amplifier side.
> 
> I wont disagree that a poor ground at the HU can cause all kinds of noise though. the ground referance between your HU and all your downstream devices will have a difference of potential. this will cause noise.


I am not sure how we explain it working fine with the old amp, unless the HU changed.
Maybe replace the HU with an iPhone to see what it does?

How do those floating grounds work? Are they a differential input microphone, but with the shield tied to the ground?


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## minbari (Mar 3, 2011)

Holmz said:


> I am not sure how we explain it working fine with the old amp, unless the HU changed.
> Maybe replace the HU with an iPhone to see what it does?


not saying the new amplifer isnt bad


> How do those floating grounds work? Are they a differential input microphone, but with the shield tied to the ground?


they can be differential, but then the input has to be able to take advantage of that too.
most they have a signal ground, that is NOT tied to chassis ground. Think of power and chassis ground as the "signals" that power the devices. the signal reference ground is a different set of wires internally. tying that signal ground to chassis ground can sometimes solve the noise problem. that is ewhy you will see people with a copper braid around the RCA sheild that is screwed to ground. if it is a truely differential system that will just blow the op amp.


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## Holmz (Jul 12, 2017)

minbari said:


> not saying the new amplifer isnt bad
> ...


Well let's focus on how to tell...
Putting the sound coming in via an iPhone or other source would get rid of the head unit as a reason for concern.

Maybe running a 110v power cord through the car would provide enough magnetic flux to see if there are ground loop issues.
One would have to pull some current through it, and ideally it would be better as a loosewire wire or a coil rather than a "twisted pair" power cable.

Or if the old amp is still working fine, then maybe have the newer one serviced.


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## Elgreco (Aug 28, 2017)

Well, I tried the new set of rca's and they didn't change anything. Surprise surprise. I will call crutchfield and either get another amp or a refund. Suggestions for an amp to power a single 12" Dayton reference HO under $250?


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## Elgreco (Aug 28, 2017)

The boss is a $100 amp. I mean, I've had it for years powering a cheap pair of dual 12's and it's held up fine. I got the box and the speakers for free so I've got my money's worth out of the setup.


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## Elgreco (Aug 28, 2017)

I talked to a different guy from crutchfield and he thinks it's not the new k1000 amp. He said he would lean towards an internal grounding issue in the radio.


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## MikeS (May 23, 2015)

Well buy a used JL XD amp, it has differential inputs as described in manuals?

Problem is there are several standards for noise rejection and there are amps that are just too cheap. They might work fine if you don't have many amps providing paths for ground loops. Measure with multimeter on ohm setting how many ohms you get from RCA shield to GND post on the amp. If you get zero reading there is no noise rejection built in at all. If you don't get a reading from the main amp, you need to get similar amp for sub to be most likely noise free.

I can measure my pioneer gm-d8601, it's similar to gm-d9601 that would fit in the price range.


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## Rzzza (Sep 19, 2017)

Its the amp! Okay so I am shocked to find this thread right now. 
I have 2 amps, its usually jlaudio jx 400/4 and jlaudio jx 500/1. The other day I swapped the jx 500/1 for the Infinity kappa k1000 and got the ground loop sound. I chased that sound for days and today I spent the whole day I rewired the whole car from head unit to each speaker and the ground and power, the remotes, everything and it's still there. This is clearly an issue with the k1000 imo It's heading back tomorrow. Shame because I already gave away my jx 500/1


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## Rzzza (Sep 19, 2017)

Elgreco said:


> Suggestions for an amp to power a single 12" Dayton reference HO under $250?


The messed up part is this Infinity WAS leaps better than the current amps available at the price point. I plan to spend more and get on the list for a ct sounds 1400.1


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## Elgreco (Aug 28, 2017)

Rzzza said:


> Its the amp! Okay so I am shocked to find this thread right now.
> I have 2 amps, its usually jlaudio jx 400/4 and jlaudio jx 500/1. The other day I swapped the jx 500/1 for the Infinity kappa k1000 and got the ground loop sound. I chased that sound for days and today I spent the whole day I rewired the whole car from head unit to each speaker and the ground and power, the remotes, everything and it's still there. This is clearly an issue with the k1000 imo It's heading back tomorrow. Shame because I already gave away my jx 500/1


So your noise sounds just like mine in the video?


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## Rzzza (Sep 19, 2017)

Mine is very high pitched sound that changes pitch with rpm.


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## Elgreco (Aug 28, 2017)

Rzzza said:


> Mine is very high pitched sound that changes pitch with rpm.


Mine does that but also makes noise with the key on engine off. Does yours do that?


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## Rzzza (Sep 19, 2017)

yes it does, like a static.


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## Rzzza (Sep 19, 2017)

Heres a video of mine


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## Holmz (Jul 12, 2017)

Plugging in an iPhone to feed the amp, will tell you if the problem is before the amp - or within the amp.

Plugging it in to the RCA from the head unit will tell you if it is before (within) the head unit, or after it.

^These^ offer the prospect of diving the problem into 1/2.

Fixing it should ideally start after some idea of where (and what) the problem is... And at least one would be working on the correct 1/2.


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## Elgreco (Aug 28, 2017)

Holmz said:


> Plugging in an iPhone to feed the amp, will tell you if the problem is before the amp - or within the amp.
> 
> Plugging it in to the RCA from the head unit will tell you if it is before (within) the head unit, or after it.
> 
> ...


I did that, and I didn't hear a noise. Tell me if I'm wrong though. The noise is a high frequency noise. It can only be heard through the tweeters. So even when I hook my phone up to the amp, the noise will never be heard because the amp only produces up to 350hz? I could be way off.


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## Rzzza (Sep 19, 2017)

Is it not as simple as unplug the rca to the k1000 and see if the noise goes away? I just did that and it went away 100% Does this not mean the issue is the k1000?


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## Holmz (Jul 12, 2017)

Rzzza said:


> Is it not as simple as unplug the rca to the k1000 and see if the noise goes away? I just did that and it went away 100% Does this not mean the issue is the k1000?


Close , but no cigar...
The amp (without a signal) making no noise, means that the amp itself is making no noise.
So the noise is being fed "into" the amp... either from the HU, or the wires between the HU and the amp.

Plug an iPhone into the wires at the HU or DSP, and with no music, is there noise or no noise?
Or
Put headphones onto the output of the HU or DSP, and see if there is noise...

You are doing good so far, so just keep narrowing down the problem space.


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## Rzzza (Sep 19, 2017)

Holmz said:


> Close , but no cigar...
> The amp (without a signal) making no noise, means that the amp itself is making no noise.
> So the noise is being fed "into" the amp... either from the HU, or the wires between the HU and the amp.
> 
> ...






Well, I think I have results from mine. I plugged my phone directly into the k1000 and I started the car and put a song on my phone. I only got sound from the subwoofer but the high freq noise went away. I've confused myself at this point so I have no clue as to wether I performed the test properly nor what the results mean to me. IDK how it could be the k1000 when the noise is coming from the front stage. Did this test help at all for you to diagnose the noise? Thanks.


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## Rzzza (Sep 19, 2017)

I just realized I'm hijacking your thread, sorry Elgreco!


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## Elgreco (Aug 28, 2017)

Rzzza said:


> Well, I think I have results from mine. I plugged my phone directly into the k1000 and I started the car and put a song on my phone. I only got sound from the subwoofer but the high freq noise went away. I've confused myself at this point so I have no clue as to wether I performed the test properly nor what the results mean to me. Did this test help at all for you to diagnose the noise? Thanks.


I'm still not sure 100%. I've got a few things I want to try. Crutchfield has a 60 day money back guarantee so I got some time.


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## Elgreco (Aug 28, 2017)

Rzzza said:


> I just realized I'm hijacking your thread, sorry Elgreco!


Hey no problem. Hopefully we can figure it out.


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## Rzzza (Sep 19, 2017)

Elgreco said:


> Hey no problem. Hopefully we can figure it out.


You think we have the same issue or just similar?


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## Elgreco (Aug 28, 2017)

Rzzza said:


> Elgreco said:
> 
> 
> > Hey no problem. Hopefully we can figure it out.
> ...


Hmmm. Not sure. I'd have to see yours in person.


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## Holmz (Jul 12, 2017)

Rzzza said:


> Well, I think I have results from mine. I plugged my phone directly into the k1000 and I started the car and put a song on my phone. I only got sound from the subwoofer but the high freq noise went away. I've confused myself at this point so I have no clue as to wether I performed the test properly nor what the results mean to me. IDK how it could be the k1000 when the noise is coming from the front stage. Did this test help at all for you to diagnose the noise? Thanks.


I see there a different amp the powers the front stage?
Or where does its cables come from?


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## Rzzza (Sep 19, 2017)

yep. There are 3 sets of rca, one goes to the k1000 and the other 2 go to the 4 channel amp. I spent another day trying things (good to be self employed) and I have come to the conclusion, I need to sell my car. 
That's only a joke but my god do I need a drink after this!


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## Elgreco (Aug 28, 2017)

I at least finally fully assembled my new box with the dayton reference 12 HO and installed it. Bumps pretty dang good with the infinity k1000. Shame I still have the whine noise. I went to a single 12 trying to save some weight but I think this setup is actually heavier lol. 3/4 mdf with the front panel 1 1/2 with a heavy sub vs 5/8 with 2 cheap duals.


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## radavis2004 (Feb 22, 2018)

Elgreco said:


> I at least finally fully assembled my new box with the dayton reference 12 HO and installed it. Bumps pretty dang good with the infinity k1000. Shame I still have the whine noise. I went to a single 12 trying to save some weight but I think this setup is actually heavier lol. 3/4 mdf with the front panel 1 1/2 with a heavy sub vs 5/8 with 2 cheap duals.




You could have used a single baffle and been fine. 


Sent from my iPhone using Tapatalk


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## MikeS (May 23, 2015)

Elgreco said:


> I at least finally fully assembled my new box with the dayton reference 12 HO and installed it. Bumps pretty dang good with the infinity k1000. Shame I still have the whine noise. I went to a single 12 trying to save some weight but I think this setup is actually heavier lol. 3/4 mdf with the front panel 1 1/2 with a heavy sub vs 5/8 with 2 cheap duals.



return the amp... let someone else bang their head against the wall.


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## Elgreco (Aug 28, 2017)

Pac rca noise filter. I figured it was worth a shot for $9. I'll have to drive the car first to confirm.
https://youtu.be/pIcgukKD4wU


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## Elgreco (Aug 28, 2017)

Drove the car around and there is no noise that is noticeable to me. I can't tell if there is any degradation in sound quality either so I may just roll with it.


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## Rzzza (Sep 19, 2017)

That's good to know. I can verify that in my case, it was the amp that caused the headaches. I went and replaced the head unit and re wired everything but after all that I still had the issue so I went to Walmart and bought a power acoustic 2500 and swapped it, the noise is gone completely. Now I am returning both of these amps and my headache for a proper working amp.


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## Elgreco (Aug 28, 2017)

Rzzza said:


> That's good to know. I can verify that in my case, it was the amp that caused the headaches. I went and replaced the head unit and re wired everything but after all that I still had the issue so I went to Walmart and bought a power acoustic 2500 and swapped it, the noise is gone completely. Now I am returning both of these amps and my headache for a proper working amp.


I'm betting the amp is the cause of the issue in my case as well. Since the little filter took the noise away I think I'll stick with it for now.


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## Holmz (Jul 12, 2017)

Elgreco said:


> I'm betting the amp is the cause of the issue in my case as well. Since the little filter took the noise away I think I'll stick with it for now.


If the filter was on the RCA going into the amp then your bet is wrong, as that RCA filters the input... so the noise is coming into the amp which faithfully amplified the noise.


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## Elgreco (Aug 28, 2017)

Holmz said:


> If the filter was on the RCA going into the amp then your bet is wrong, as that RCA filters the input... so the noise is coming into the amp which faithfully amplified the noise.


All I know is we have two people in this thread with the same amp with different setups with a noise. With my old amp, no noise. With the filter, no noise. Rzzza had a JL audio amp, no noise. Installed k1000, has noise. Installed power acoustik amp, no noise.


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## Holmz (Jul 12, 2017)

Elgreco said:


> All I know is we have two people in this thread with the same amp with different setups with a noise. With my old amp, no noise. With the filter, no noise. Rzzza had a JL audio amp, no noise. Installed k1000, has noise. Installed power acoustik amp, no noise.


Yes but correlation does not prove causality.
I consider myself as having a decent grasp on trouble shooting, or maybe I am just deluded?

If one runs a different source, like a iPhone into the amp, and there is no noise, then it means that the amp/speaker combo is not producing noise... hence the noise must be "coming into" the amp.

If a different amp has no noise then it is either that the wiring changed, or that the amp is configured internally to be somehow more immune to noise.

If the RCA filters worked, then it is a bit academic now, so just enjoy it. At this point life is good again.


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## Elgreco (Aug 28, 2017)

Holmz said:


> Yes but correlation does not prove causality.
> I consider myself as having a decent grasp on trouble shooting, or maybe I am just deluded?
> 
> If one runs a different source, like a iPhone into the amp, and there is no noise, then it means that the amp/speaker combo is not producing noise... hence the noise must be "coming into" the amp.
> ...


One thing I've learned wrenching on cars for 10 years, sometimes you just can't figure out why or how. I've seen some weird problems. I once had a car that the wiper switch was back feeding power to the pcm. Causing like 20 codes and draining the battery. Took me weeks to figure that one out.


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## Holmz (Jul 12, 2017)

Elgreco said:


> One thing I've learned wrenching on cars for 10 years, sometimes you just can't figure out why or how. I've seen some weird problems. I once had a car that the wiper switch was back feeding power to the pcm. Causing like 20 codes and draining the battery. Took me weeks to figure that one out.


Whether one can figure it out or not, there is an actual cause.

I am 90% sure that you probably cleared codes, and then started turning stuff on until started getting codes???
If it was not repetable then you probably would not have found the cause. Since you did find it, then it must have been repeatable.
(Good job)


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## Elgreco (Aug 28, 2017)

Holmz said:


> Whether one can figure it out or not, there is an actual cause.
> 
> I am 90% sure that you probably cleared codes, and then started turning stuff on until started getting codes???
> If it was not repetable then you probably would not have found the cause. Since you did find it, then it must have been repeatable.
> (Good job)


No. The wipers did not have to be on. It was random. You could drive the car for days and it wouldn't happen. Essentially what was going on is the wiper switch was randomly feeding enough voltage to the pcm to wake it up, but all the other modules were asleep. The pcm talks with the other modules to get info about sensors and stuff. Since it was not getting the info, it was throwing codes for everything it was looking for. I'm sure if you spent enough time and money on mine or rzzza's car you could find the actual cause. Installing the filter or a different amp is easier lol.


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## Rzzza (Sep 19, 2017)

Bad news for me. I got my new amp in today Skar rp1500.1. 
I ran it at 2 ohm for 1000 watts and my ground loop is back. So apparently it has to do with the amount of power my mono amp pushes because the two 500 watters didn't do it and the two 1000 watters do it. 
So I heard it very bad right after the amp swap today, it was just like the k1000. Then I went for a ride just now and I can barely hear it, but it is for sure there. I don't know yet if its only present for certain sources or what, frankly I feel like giving up completely. That would be a shame, I have a nice ct sounds meso I want to build a box for next but this noise is frustrating. On top of the whine there is always the presence of static, I hate that. Just as important as the sound of the music, I appreciate the clean, silent background just as much and that just seems impossible.
On top of all this, my new android HU changed the sound of my music a whole lot. Now I am debating to go back to a sony or Kenwood and sending this back. It's that much of a difference. Ugh it shouldn't be this difficult! lol I don't even know where to go from here, guys! I will try any suggestions you may have though.


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## mitchell0715 (Apr 11, 2015)

Rzzza said:


> Bad news for me. I got my new amp in today Skar rp1500.1.
> I ran it at 2 ohm for 1000 watts and my ground loop is back. So apparently it has to do with the amount of power my mono amp pushes because the two 500 watters didn't do it and the two 1000 watters do it.
> So I heard it very bad right after the amp swap today, it was just like the k1000. Then I went for a ride just now and I can barely hear it, but it is for sure there. I don't know yet if its only present for certain sources or what, frankly I feel like giving up completely. That would be a shame, I have a nice ct sounds meso I want to build a box for next but this noise is frustrating. On top of the whine there is always the presence of static, I hate that. Just as important as the sound of the music, I appreciate the clean, silent background just as much and that just seems impossible.
> On top of all this, my new android HU changed the sound of my music a whole lot. Now I am debating to go back to a sony or Kenwood and sending this back. It's that much of a difference. Ugh it shouldn't be this difficult! lol I don't even know where to go from here, guys! I will try any suggestions you may have though.


Very likely it has to do with your amp ground if it is the case that higher power amplifiers cause the issue to appear


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## Rzzza (Sep 19, 2017)

mitchell0715 said:


> Very likely it has to do with your amp ground if it is the case that higher power amplifiers cause the issue to appear


Ok that is my next fix. I will run that ground as perfect as possible. Admittedly I don't love the spot now. I can show a picture maybe you have a suggestion?

Please note that the ground connection I am pointing at is the 4 channel amp. The ground in question, is actualy the very bottom of the picture. 

upload a pic on the internet


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## Elgreco (Aug 28, 2017)

I would ground them at the same spot, and try and through bolt it if you can. Use an actual nut and bolt, sand the paint down to bare metal.


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## Elgreco (Aug 28, 2017)

That's how I ground mine. Use dielectric grease to avoid corrosion.


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## FlyingEagle (Sep 22, 2017)

I must be staring at the same screws you guys are ... they are coated black/oxide for corrosion resistance ... no where near ideal. If the star washer and the ground eyelet are the only points making contact to the body ... I think there is a very good chance this is the problem. As stated by a chap above me, you need to get a larger contact area for sure. Definitely try the clean non coated parts when doing this. You can always put contact grease over things once they are installed to keep corrosion to a minimum. The biggest issue at that point would be two dissimilar metals corroding over time.


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## mitchell0715 (Apr 11, 2015)

Is there a THICK piece of metal nearby you can ground to, like a frame rail? It kinda looks like you're gounded nearby the spare tire well? I would be willing to be there's some sort of weld, insulation, or other high resistance in the way

Look around for grounds the car is using for other components

You may need to try a few different spots. Unibody cars can have serious issues with grounding

The star washer is on top of the lug not below it.. right?..


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## Rzzza (Sep 19, 2017)

mitchell0715 said:


> Is there a THICK piece of metal nearby you can ground to, like a frame rail? It kinda looks like you're gounded nearby the spare tire well? I would be willing to be there's some sort of weld, insulation, or other high resistance in the way
> 
> Look around for grounds the car is using for other components
> 
> ...


I'm pretty sure I have a simple 1/8" hole drilled into the body of the car and then u terminal then star washer then screw head


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## Rzzza (Sep 19, 2017)

how bout using these bolts? They are heavy duty, large and they contact a bare ray steel rather than the treated steel its on now. I circled in yellow



image hosting


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## mitchell0715 (Apr 11, 2015)

Rzzza said:


> how bout using these bolts? They are heavy duty, large and they contact a bare ray steel rather than the treated steel its on now. I circled in yellow
> 
> 
> 
> image hosting


Those might work but you need to get the terminal under the black bracket and you still will need to sand down the metal until its bare


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## Holmz (Jul 12, 2017)

Ideally one sees if the the noise is present at the output of the HU...
I am pretty sure it is present on the input to the amp, so it is either there at the HU, or coming in along the RCA cables...


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