# Alternator whine in 1 speaker



## pit viper (Jun 28, 2012)

Setup:
MS-8
Boston Acoustics 6.5" front components
Infinity Kappa 4" coax center speaker
Stock rears
Elemental Design nine.4 powering all fronts, MS-8 powers rears

I have bad alternator whine from just the center speaker. I removed it from the dash, still a whine. Replaced it with the other Kappa, still whines. Ran new wire from the amp, outside the car to the speaker sitting on the seat, still whines. Switched the RCA inputs with one of the front components, and the whine stayed with the center speaker. Ran a new RCA from the ms-8 to the amp, still whines. If I unplug the RCA, the whine goes away. The whine is there when the RCA is plugged in, whether the radio is on or off. I even tried using the unused channel of the amp, no change.

Do Kappa 42.9i's just whine no matter what? The pitch changes with engine speed. I'm out of ideas.


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## analogrocker (Aug 1, 2009)

I doubt it's the speaker - speakers don't just whine. It sounds like you tried everything. Could be a problem internally with the amp. I assume the other speakers connected to the other channels of the amp don't have any whine at all? If not, then it can't be a grounding issue. Definitely sounds like something internally wrong with the amp.

*Edit:* I just Googled that Infinity speaker, and it looks like it uses an outboard crossover. Are you using that? If so, that could have something wrong internally.


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## pit viper (Jun 28, 2012)

The crossover comes pre-wired to the speaker, so when I tried the other speaker, I automatically tried a different crossover, too.


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## simplicityinsound (Feb 2, 2007)

this should be simple to figure out.

lets do it one step at a time:

1. shut down your system. meaning pullt he master fuse out. do you still have whine out of it?


u wouldnt happen to have some type of german vehicle such as a late model bmw, mercedes or audi would you?


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## pit viper (Jun 28, 2012)

simplicityinsound said:


> this should be simple to figure out.
> 
> lets do it one step at a time:
> 
> ...


Thankfully, no. I had a 2000 A6 I sold to get this car, a 2008 Pontiac G8 GT.


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## simplicityinsound (Feb 2, 2007)

i was also gonna say "or a rear battery vehicle" 

but do that first thing and i will walk you through it.


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## simplicityinsound (Feb 2, 2007)

oh after that, do this...on the nine.4

unplug the front left and right speaker wires (which as you stated had no whine) and put the center channel to one of those channels, and see if the whine dissapears.


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## The Baron Groog (Mar 15, 2010)

Seen the exact same thing reported previously-it was the MS8 "causing" it, one of the RCAs from the MS8 was by an earthing point, the OP moved his earth and cured the issue-so try that.


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## simplicityinsound (Feb 2, 2007)

The Baron Groog said:


> Seen the exact same thing reported previously-it was the MS8 "causing" it, one of the RCAs from the MS8 was by an earthing point, the OP moved his earth and cured the issue-so try that.


i thought he switched the rcas on the amp and it didnt make a difference? as in the rcas plugged into channels that had no noise on the amp still had noise on the center channel?


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## 07azhhr (Dec 28, 2011)

simplicityinsound said:


> i thought he switched the rcas on the amp and it didnt make a difference? as in the rcas plugged into channels that had no noise on the amp still had noise on the center channel?


That is what I took out of the posts as well. It sounds like an amp issue. 


Question for you on the battery thing. Why would a rear mounted battery creat alt wine? I have two cars with rear batteries stock and zero whine in either system so I am curious why one would think the rear battery could cause it.


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## pit viper (Jun 28, 2012)

simplicityinsound said:


> this should be simple to figure out.
> 
> lets do it one step at a time:
> 
> 1. shut down your system. meaning pullt he master fuse out. do you still have whine out of it?


I pulled the fuse, and there's no whine from the system. 
I'll have to try swapping the wires to channel 1 or 2 after work, as I don't have my tools at work.



simplicityinsound said:


> i thought he switched the rcas on the amp and it didnt make a difference? as in the rcas plugged into channels that had no noise on the amp still had noise on the center channel?


True.


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## The Baron Groog (Mar 15, 2010)

pit viper said:


> Setup:
> Switched the RCA inputs with one of the front components, and the whine stayed with the center speaker. Ran a new RCA from the ms-8 to the amp, still whines. If I unplug the RCA, the whine goes away. The whine is there when the RCA is plugged in, whether the radio is on or off.





simplicityinsound said:


> The Baron Groog said:
> 
> 
> > Seen the exact same thing reported previously-it was the MS8 "causing" it, one of the RCAs from the MS8 was by an earthing point, the OP moved his earth and cured the issue-so try that.
> ...


No, he said he;
1. Switched the inputs to the MS8 and the noise stayed there: if the RCA input position is close to an earth the problem would still exist

2. Ran a new RCA from the ms-8 to the amp, still whines: even with a new RCA in place (same position I'd warrant) he's still getting the noise

3. He unplugged the RCA (I presume from MS8 to amp) and the noise goes: noise is in the MS8 to amp chain

As he's replaced the RCA and the noise is still there it leaves the MS8 or as I believe to be the issue the route of the RCA to the MS8 from the HU or the route of the RCA from MS8 to amp. As said I read another post where someone had same issue and found it to be either an input to or output from the MS8 being close to an earth causing the issue.


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## The Baron Groog (Mar 15, 2010)

10mins of searching through my old threads....:

http://www.diymobileaudio.com/forum...n/127562-unusual-ms-8-noise-issue-solved.html


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## 07azhhr (Dec 28, 2011)

Baron re-read the first quote. Pit is saying that he switched the input rca's from one of the two front channels to the center channel and it stayed there. He is meaning at the amp and he confirmed that in the post above yours at the bottom. 

Unless he is feeding the MS8 with front/center/rear/sub rca's from the head unit then he could not have switch the inputs of the MS8.


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## grg-argy (Jan 6, 2012)

I had the same problem. The whinie came from the crossover , when i change the crossover position the problem solved!!!


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## The Baron Groog (Mar 15, 2010)

07azhhr said:


> Baron re-read the first quote. Pit is saying that he switched the input rca's from one of the two front channels to the center channel and it stayed there. He is meaning at the amp and he confirmed that in the post above yours at the bottom.
> 
> Unless he is feeding the MS8 with front/center/rear/sub rca's from the head unit then he could not have switch the inputs of the MS8.


My mistake, though I'd still recommend the OP read the thread, still sounds like the issue cured in it.


Sent from my Motorola DynaTAC using Tapatalk


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## pit viper (Jun 28, 2012)

I read your thread, and it may yet be helpful. I'm going to try swapping the speaker wires between the amp channels first.

FWIW, I'm using the stock head unit, so there's no rca's between the HU and the MS-8. I am pulling the signal from the front speaker wires and the stock amp.


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## pit viper (Jun 28, 2012)

simplicityinsound said:


> oh after that, do this...on the nine.4
> 
> unplug the front left and right speaker wires (which as you stated had no whine) and put the center channel to one of those channels, and see if the whine dissapears.


I did this. The whine is still there, but reduced.


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## simplicityinsound (Feb 2, 2007)

okay...here is what i think is happening.

your amp is inducting noise directly into its circuit board. 

where exactly is the amp in relation to the master OEM cable that runs from the alternator upfront to the rear battery? 

you can try two things here:

1. this may be a stretch but if you jerryrig something you can confirm this. take some extra power cable and just like elecrical tape it to your existing power cable, alsoextend your remote wire and speaker wire...just for the centr, and then literally extend the amp somehwere else...away from the car's battery, and away from he car if possible. see if the noise then goes away.

2. if you verify the above issue, there is only one possible soltuion that may or may not work, purcahse this: MSD Ignition 8830 - MSD Noise Filters - Overview - SummitRacing.com

and cap your alternator, on your car, you can do this simply by putting this cap onto the jumping terminals upfront under the hood. see if this gets rid of the noise.

if this does NOT, then unfortunately you have very little choice but to either relocate the amp somehwere far away from the oem power cable battery, or get a new amp. 

when there is noise in one speaker, its usually being inducted into the amp, the speaker wires, passive xovers, and or even the cap on a speaker. but you eliminated some when you said the noise was gone when you disconnected the system...so that leaves us with the amp.


my guess is that your left and right speakers also have some whine but just a bit less...to the polint that its not really audible.

b


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## simplicityinsound (Feb 2, 2007)

07azhhr said:


> That is what I took out of the posts as well. It sounds like an amp issue.
> 
> 
> Question for you on the battery thing. Why would a rear mounted battery creat alt wine? I have two cars with rear batteries stock and zero whine in either system so I am curious why one would think the rear battery could cause it.


i didnt mean rear battery i mean battery and alternator at opposite ends of he car  bascally, a long and thick OEM power cable running down the entire length of the car.

in these types of cars, its much more common to get inducted noise radiating from that side. for example, with most newer bimmers, i can do a fun lil test, by taking a passive xover (almost any passive), just hook up a tweeter to it. and then put the tweeter to your ear and then pass the passive anywhere close to the passenger side battery, or main oem power cable with the car running, and you hear some pretty loud whine 

As for the exact science of why this occurs, someone explained it to me once but i dont remembr enough of it to repost it lol something about AC ripple? i dont remember.

but i can tell you that my own experience echos this and i take extra pre-caution when doing cars with this type of setup

it varies with car, cars that are especially prone to this are late model german cars such as bmws and mercedes. 

b


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## pit viper (Jun 28, 2012)

simplicityinsound said:


> where exactly is the amp in relation to the master OEM cable that runs from the alternator upfront to the rear battery?


The master cable runs down the driver's side of the car, as the battery is located right behind the driver's side rear wheel. The amp is mounted to the back of the passenger side rear seat.


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## simplicityinsound (Feb 2, 2007)

move the amp around as i mentioned. see if you can less the noise. i have had a few amps induct noise directly onto the CB before. and with four channel amps, its very common that two channels are quieter than the other two, due to the layout of the amp, soemtimes, they are on two seprate boards that can be more or less prone to noise.

b


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## pit viper (Jun 28, 2012)

simplicityinsound said:


> move the amp around as i mentioned. see if you can less the noise. i have had a few amps induct noise directly onto the CB before. and with four channel amps, its very common that two channels are quieter than the other two, due to the layout of the amp, soemtimes, they are on two seprate boards that can be more or less prone to noise.
> 
> b


I'll try that out. Thanks again for all your help on this!


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## 07azhhr (Dec 28, 2011)

simplicityinsound said:


> i didnt mean rear battery i mean battery and alternator at opposite ends of he car  bascally, a long and thick OEM power cable running down the entire length of the car.
> 
> in these types of cars, its much more common to get inducted noise radiating from that side. for example, with most newer bimmers, i can do a fun lil test, by taking a passive xover (almost any passive), just hook up a tweeter to it. and then put the tweeter to your ear and then pass the passive anywhere close to the passenger side battery, or main oem power cable with the car running, and you hear some pretty loud whine
> 
> ...


I knew what you ment as far as relationship to the alternator which should be apparent by the fact that I said I have two cars with stock rear mounted batteries and my user name contains one of those cars. Both are GM's like the OP's car is. I have no noise issues do to this rear battery front alternator.

If BMW and Mercedes cannot prevent that kind of noise then perhaps they should fire some of their engineers since GM can do it. Again both my current cars have amps mounted near the battery in the rear of the car with the alt in the front of the car AKA oposite ends of the car. Heck in my HHR the cars main power wire runs directly next to my amp.


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## 07azhhr (Dec 28, 2011)

Pit - what type of speakers are the fronts vs the center? I think Bing (simplicity) is correct in that the left and right speakers must be just very reduced. Perhaps something about those speakers/x-overs are less prone to noise or something. Have you tried to put one of the fronts on the center channel by chance?


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## pit viper (Jun 28, 2012)

07azhhr said:


> Pit - what type of speakers are the fronts vs the center? I think Bing (simplicity) is correct in that the left and right speakers must be just very reduced. Perhaps something about those speakers/x-overs are less prone to noise or something. Have you tried to put one of the fronts on the center channel by chance?


The fronts are BA 6.5" components. The center is an Infinity Kappa 4" 42.9i.

I noticed today, in driving around with no music on, that I'm also getting feedback through that center speaker when the blinkers are on, and when I hit the brake pedal. It's not the whine I'm getting from the alternator, but more of a light pink noise that starts when the brake pedal is depressed at all, or when the blinkers are on.


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## 07azhhr (Dec 28, 2011)

If it is at all feasible perhaps try powering the center off of the MS-8 and see if things change. 


Are you pulling from your stock amp at the front speaker outs or front speaker ins? If from the output then perhaps try from the input insted. 

The static and whine could be seperate issues but they tend to be related to one another. When you had the speaker in the passanger seat witha new set of speaker wire running to it you still had the whine. Try this same thing with the static conditions and see if you still have it.


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## pit viper (Jun 28, 2012)

The stock amp only powered the rear-deck 8" subs, and I'm pulling that signal post-amp. The signal for the front speakers is pulled from the wires heading from the head unit to the speakers.



07azhhr said:


> The static and whine could be seperate issues but they tend to be related to one another. When you had the speaker in the passanger seat witha new set of speaker wire running to it you still had the whine. Try this same thing with the static conditions and see if you still have it.


I'll try to test this tonight.


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## 07azhhr (Dec 28, 2011)

Where did you ground the amp and the MS-8? If they are not grounded to the stock battery ground location in the trunk then try moving them to that bolt.


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## SuMb0dY (Oct 23, 2012)

Did you ever solve all the noise?

I have one speaker giving me noise in my system now and read through this for ideas. After doing a bunch of different experimenting I believe I have an amplifier with one bad channel. Any ways I can confirm this before I go through the process of replacing the amp?


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## The Baron Groog (Mar 15, 2010)

Swap the speaker wires over, if the problem remains with the amp channel then try swapping the RCAs.


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## SuMb0dY (Oct 23, 2012)

I switched up the speaker wiring and the problem left one tweeter and went to the other one. So its definitely not the speakers because they are both capable of playing clean which is a relief cuz their $$$.

I also ran new speaker wire outside the vehicle and this had no effect. I believe this rules out the possibility of a clipped/grounded speaker wire or a wire getting noise from nearby power lines.

The problem seemed to have stayed with the amp channel. 

I tried another set of rcas run outside the vehicle and that had no effect - still one whining on whichever speaker is connected to the amp left channel. I also tried flipping the rca ( switching the red and white side) and this also had no effect on the noise. I believe this means it is indeed the amp channel and rules out that its coming from the HU.

Let me know if you think my conclusions are correct.

Also i do have passive crossovers i am using in between the amp and the components however i also switched the wiring on those and it seems they were both able to send clean sounds to the tweeters which i think also points toward the amp as the issue.

Throughout the process of testing different wirings i never moved the position of the amp or crossover, they all stayed screwed down to their board in the trunk.

I think i tried every combination, it seems both tweeters and crossovers are fine on the amp right channel but they all get noise on the amp left channel.

Sent from my SCH-I535 using Tapatalk 2


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## MarkZ (Dec 5, 2005)

Agreed ^^^ This will tell you exactly what's wrong. If you can isolate it to either the RCAs or speaker cables, you'll save yourself the hassle and expense of buying a new amp. Lots of times this is one of the symptoms with a pinched/shorted speaker wire or terminal. Ditto for RCA cables.


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## The Baron Groog (Mar 15, 2010)

Seems to be the amp-try fitting another in it's place.


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## SuMb0dY (Oct 23, 2012)

Thanks for looking through my post and giving suggestions guys. 

Bummer I probably have a bad amp

Ill post results with a different amp hopefully tonight. I have a spare 2 channel kenwood KAC 7205 from an old subwoofer i was using so maybe that will do the trick

Sent from my SCH-I535 using Tapatalk 2


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## SuMb0dY (Oct 23, 2012)

Yup turns out the old amp didnt have wine. Good thing my amp is on sale, paid 150 for a new GT 2200. Comes on monday. Ill consider it an awesome day if the wine is gone for good with the new amp.


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## SuMb0dY (Oct 23, 2012)

Holy **** the new GT 2200 wines in the same speaker :banghead:

I tested a different amp just using all the same wires and that one was fine. Did i get two equally defective amps? Is that possible? Or does my setup just hate that model amp? 

Ready to tear my hair out by now


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## ATOMICTECH62 (Jan 24, 2009)

Sounds like that style amp has an internal common ground problem with the one channel.If that amp were here it would already be on the bench.
probably just needs a small wire soldered in place.


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## SuMb0dY (Oct 23, 2012)

ATOMICTECH62 said:


> Sounds like that style amp has an internal common ground problem with the one channel.If that amp were here it would already be on the bench.
> probably just needs a small wire soldered in place.












Come to think of it the amp is a bit close to the crossover as well, could their close proximity to eachother cause interference?

In this photo I was testing a seperate amp, which worked fine. Ill have to try to move the crossover and see if that changes anything. I wouldnt know how to deal with opening the amp up, im still a beginner


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## SuMb0dY (Oct 23, 2012)

ATOMICTECH62 said:


> Sounds like that style amp has an internal common ground problem with the one channel.If that amp were here it would already be on the bench.
> probably just needs a small wire soldered in place.


Atomictech62,

I Tested the amp moving crossovers to no effect. Seems the kenwood amp is able to drive the speakers totally fine but both GT amps have same whine issue. 

That being said, Id like to use the GT amp if i can without whine. Its power output, THD, and signal/noise numbers are all very impressive at that price point and its a difference I can really hear - the thing sounds freakin great. 

Not to mention all the hardwork I put into making an amp rack that looks good fitting the GT so well... so Id love to see one on there.

Do you know if theres a good person I can find to look into fixing the amp for me? Or a clear DIY guide I can follow?

Im near NYC so looks like im a bit far from you


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## ATOMICTECH62 (Jan 24, 2009)

Most amps just have a common ground on the RCA's.So if only one RCA coming in has a good ground then it will ground the other input as well.The outer sleeves of booth left and right RCA's will show a dead short or close to it(less than 1 ohm)if you connect a ohm meter to them.If they dont then they have individual grounds.So if only one RCA in has ground and the other one doesnt then there will be noise in the ungrounded channel.
Therefor if the one amp works it should have a single common grounding input.
This would mean that the JBL doesnt send a ground with all channels.
Check all the grounds with reference to each other RCA ground on the JBL with a volt /ohm meter.
If they all have common grounds then the amp has an internal ground problem that is not normal and needs to be modified or returned.
The GT amp must use a ground for each channel.


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## SuMb0dY (Oct 23, 2012)

ATOMICTECH62 said:


> Most amps just have a common ground on the RCA's.So if only one RCA coming in has a good ground then it will ground the other input as well.The outer sleeves of booth left and right RCA's will show a dead short or close to it(less than 1 ohm)if you connect a ohm meter to them.If they dont then they have individual grounds.So if only one RCA in has ground and the other one doesnt then there will be noise in the ungrounded channel.
> Therefor if the one amp works it should have a single common grounding input.
> This would mean that the JBL doesnt send a ground with all channels.
> Check all the grounds with reference to each other RCA ground on the JBL with a volt /ohm meter.
> ...












Okay so heres the rca inputs on the Kenwood. (Amp that works with no noise)

I connect the multimeter to the outer sleeves pf the rca inputs like such and i get a nice low ohm reading. About 0.2

I do the same to the GT amp and it reads like 30 ohms. No good?

What if i were to wrap a wire around both the outer rca sleeves to connect them to eachother so if one is grounded then they both will be. Like this









Is that what u meant on how to make sure their both grounded?


I opened up the amp but i have no idea whats going on inside there, i cant tell what its grounds are. I put the multimeter on the outer rca sleeve and the amp ground terminal but got way over 1 ohm there on all rca inputs


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## ATOMICTECH62 (Jan 24, 2009)

Yes you can give that a try.Some times that works,sometimes it makes it worse.
If it does work then soldering a jumper on the board will solve your problem.

Do not use the ground terminal that feeds power to the amp.
The RCA grounds will be isolated from the power ground.The RCA ground comes relative from the center tap on the transformer in the amp.


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