# Speaker and tweeter static noise won't go away. Alternator whine remnant...



## Bmwe39528i (9 mo ago)

As to not waste your time with details I'll jump into the issue and what I tried so far.

Whining gets was worse when revving the engine. I understand it's called alternator whine.

Unplugging rca cables at the amp for front and rear speakers removes the whine.

Connecting my phone via Y cable to the amp eliminates the whine.

Both amps (for sub and speakers) grounded at the same chassis ground.

I tried 2 different headunits, no difference.

I tried powering one speaker directly from the headunit and not the amp - no noise.

Headunit is grounded into the metal bar under the dash.

I tried inline noise isolator filter between headunit and its power supply
No change at all
Axxess AX-ANR1000 Inline Power Noise Filter Axxess AX-ANR1000 Inline Power Noise Filter : Amazon.ca: Electronics

Tried 4 Farad power capacitor

Tried 3 rca noise isolator filters on amp side ams headunit side.

Connecting a filter just for rear or front rca cables reduces the whine. But plugging a noise isolator filter on both front and rear rca's, the noise is way worse than plugging only one filter.

I'm probably forgetting some stuff I tried.

I'm literally losing my mind over this and it's driving me crazy

My system is completely separate from stock audio.
One sub, 2 amps, 4 speakers and tweeters, 4 crossovers, headunit. All expensive quality components.
Power is through 0 gauge wire.

Tried grounding the amps on the battery negative instead of the body, no change. Rca cables are all high quality.

I tried powering one crossover directly from the headunit, just using wires from the pin plug, not rca.
This way there was no noise for that speaker and tweeters!

Tried grounding headunit rca female grounds directly to the headunit chassis.

I'm at a loss what could be the problem...


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## INFRNL (Feb 19, 2021)

What amps are you running? Maybe you are using the wrong RCA cables; depends on the amps used.
Typically alternator whine, noise from power windows is a ground issue but could be an issue wit the amps as well.

I think there was another similar thread recently started but not sure if that guy has made any headway either.


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## Bmwe39528i (9 mo ago)

Amps are 
Infinity REF-704a and Kenwood KAC-9106D
Rca cables are Fospower that go from the headunit to the speaker amp.
For the sunwoofer amp, cables are Fison and have an arrow on them. Arrow is pointed in direction of the sub amp.
Headunit is Kenwood Excelon KDC-X304 although I believe I ruled out HU as an issue.


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## NW JLUR (Dec 3, 2018)

Just a few things I can think of…. Is the ground for the amp good? Sanded, bolted to the frame or a thick area of the body, to bare metal, and sealed? Have you tried grounding your radio, amps and anything else to one location? What about using an external audio source directly into the amp? Check battery connections, factory grounds under the hood or upgrade the grounds. Last thing I can think of is maybe you’ve got a bad spark plug wire?


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## humandrummachine (May 17, 2010)

OP says he tried grounding amps to negative on battery so that should eliminate the ground as a problem. I don't think the RCA cables can be considered quality, from a quick online search they seem sketchy. From all the tests, it seems like the problem stays with your RCA cables.


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## Thor23278 (May 4, 2020)

First try the RCA's.

If that doesn't work, try blowing up your engine, rebuilding it, and make sure to clean all the chassis grounds as you're putting the engine back in. At least that fixed the whine I had tried to isolate for a year. 

Seriously though, I did find two broken chassis grounds. One mid frame at my exhaust and one in my engine bay when I pulled the motor out. No idea how the engine bay one got broken, but it was an '09 with 185k miles on it.


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## Bmwe39528i (9 mo ago)

NW JLUR said:


> Just a few things I can think of…. Is the ground for the amp good? Sanded, bolted to the frame or a thick area of the body, to bare metal, and sealed? Have you tried grounding your radio, amps and anything else to one location? What about using an external audio source directly into the amp? Check battery connections, factory grounds under the hood or upgrade the grounds. Last thing I can think of is maybe you’ve got a bad spark plug wire?


Yes its a bmw, so the battery is in the back.
Good clean ground. X5 2002 has a grounding point in the trunk. Can take pictures.
I didn't ground them to the same location, because the headunit is in the front and amps are in the back. But I could run headunit ground to the back. I checked ohm resistance between grounds, it's negligible. 
What do you mean by a bad spark plug wire?


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## Bmwe39528i (9 mo ago)

humandrummachine said:


> OP says he tried grounding amps to negative on battery so that should eliminate the ground as a problem. I don't think the RCA cables can be considered quality, from a quick online search they seem sketchy. From all the tests, it seems like the problem stays with your RCA cables.


I tried different rca cables as well.
I tried just connecting straight across, not running them under the carpets. I.e. just connecting different rca cables from head unit to the amps. Still the same problem.
I can buy better rca cables and try that


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## humandrummachine (May 17, 2010)

What RCA's have you tried? 

If you have a multimeter you could try measuring the AC voltage levels that your alternator is putting out. If its too high it can mean your alternator is having an issue and emitting noise. Similar to a bad spark plug wire which would be emitting ignition noise.


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## Bmwe39528i (9 mo ago)

Thor23278 said:


> First try the RCA's.
> 
> If that doesn't work, try blowing up your engine, rebuilding it, and make sure to clean all the chassis grounds as you're putting the engine back in. At least that fixed the whine I had tried to isolate for a year.
> 
> Seriously though, I did find two broken chassis grounds. One mid frame at my exhaust and one in my engine bay when I pulled the motor out. No idea how the engine bay one got broken, but it was an '09 with 185k miles on it.



I cleaned up the grounding points on the engine with a wire brush. There's a wire from the engine to the chassis, all cleaned up. Other grounds under the good seem clean.
It's tricky for sure, but engine rebuild is a little too much as this point haha. I ulready overhauled everything under the hood and installed a punch of new parts.


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## INFRNL (Feb 19, 2021)

I just reread your original post. It sounds like you are getting the noise from the RCA's of the HU and the amps.
You don't have the noise when using deck power.
You don't have noise using phone directly to amps.
To me this sounds like the HU unit is picking up the noise and sending it to the amp, or the noise is being picked up from the RCAs.

This may be a pain but can you temporarily use an amp up front near the HU; just for testing purposes?


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## Bmwe39528i (9 mo ago)

I can certainly test alternator amperage output. Easy step.
Not sure how to test spark plugs.

My buddy who ordered rca cables said they were good quality. The other rca cables I used were just some random cables I found when I removed previous installation from this vehicle.

I mean the subwoofer amp rca are different from speaker amp rca's. I can try them for front speakers amp. Subwoofer amp doesn't produce and problematic noise. The cables must be good?

I'm afraid that moving the amp to the headunit would be too hard. The 0 gauge power cable to the amp is not long enough.

Can I move the headunit to the amp instead?

My headunit only needs 3 wires. Power, ignition and ground.
I can ground headunit to the same bolt where amp is grounded and I can use power directly from the battery. I can just tape the red (ignition wire) and yellow (constant power) together for the time being and connect it directly to the battery terminal. 

Another thing I was thinking. I have a battery charger, 2/10/75 amp. I was thinking what if I disconnect the audio system from the battery and just power it with battery charger for testing?

You say maybe the headunit picks up noise. But I do have that inline noise filter installed between yellow (constant power) wire and the headunit.


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## Dwarteacher (Oct 17, 2020)

Here is something radical. Try grounding the amp's body. If I remember right, some amps have an internal chassis ground.


Here is an Alpine BB1200 with chassis ground. I had no noise issue using it mounted on a board without an external chassis ground. If your amplifier has an internal chassis ground, try an external ground on one screw down point, and see if the noise disappears.


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## knever3 (Mar 9, 2009)

Do you have any 12V tools? You could use a battery from one and power your head unit like you mentioned about the charger. Usually chargers are very noisy so might not be the best choice for 12V. Have you tried running a wire from the radio ground directly to the battery negative? If you have a grounding problem that is introducing noise at some point pull the deck so it's not touching any ground of the vehicle and get a speaker wire or any wire that is at least 16 gauge and ground it directly to the battery. You need to find out where the noise is being transmitted through. I don't believe you have a bad deck, but noise is coming from somewhere.


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## LBaudio (Jan 9, 2009)

first route positive and negative wires from the same spot as you use it for all the rest components in the system. Reduce gains on amps, check if rca cables run parallel with power cables, or are they in close proximity to cars computer, fuel pump,....


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## Selkec (Nov 18, 2018)

humandrummachine said:


> What RCA's have you tried?
> 
> If you have a multimeter you could try measuring the AC voltage levels that your alternator is putting out. If its too high it can mean your alternator is having an issue and emitting noise. Similar to a bad spark plug wire which would be emitting ignition noise.


this….Bad diodes in the alternator will cause noise because of a tiny AC ripple. Most car shops can test this… a multimeter won’t do you any good

Also I didn’t read it all but there is different rca types. Twisted pair is one type. I can’t remember the other. It’s too early in the morning still


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## nyquistrate (Apr 17, 2011)

Selkec said:


> this….Bad diodes in the alternator will cause noise because of a tiny AC ripple. Most car shops can test this… a multimeter won’t do you any good
> 
> Also I didn’t read it all but there is different rca types. Twisted pair is one type. I can’t remember the other. It’s too early in the morning still



You can measure AC with a multimeter.

OP, what happens with the engine off? Do you still have noise?


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## nyquistrate (Apr 17, 2011)

Selkec said:


> this….Bad diodes in the alternator will cause noise because of a tiny AC ripple. Most car shops can test this… a multimeter won’t do you any good
> 
> Also I didn’t read it all but there is different rca types. Twisted pair is one type. I can’t remember the other. It’s too early in the morning still



You can measure AC with a multimeter.

OP, what happens with the engine off? Do you still have noise?


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## Selkec (Nov 18, 2018)

nyquistrate said:


> You can measure AC with a multimeter.
> 
> OP, what happens with the engine off? Do you still have noise?


Yes I know this. But you need a oscope to show the ac ripple. If there is a ripple it’s a bad diode. Just measuring and seeing ac with multimeter doesn’t confirm its a bad diode. Most shops have a snapon meter that has the option to detect it


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## Bmwe39528i (9 mo ago)

Lots of suggestions to try! I just left for a week but will be back, try everything that was suggested and will post results.


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## unseenme (Apr 16, 2012)

I had this problem and here’s what fixed mine. I have an old school Rockford Punch 100.2 from 2000 that had a serious alternator whine/ground loop noise. It was happening in the left channel only because my left midrange would not play and the engine noise was horrible. I took the bottom of the amp case off and trimmed the amp RCA input connector on the underside of the amp board. They protrude through the bottom of the amp board. They looked a little long, like they may be touching the amp frame so I trimmed it down. I then mounted the amp back to the amp wall (which is wood) without installing the bottom frame which is also the side frame. Voila. No more noise. I’m no electrical engineer so I have no idea what the problem was but I figure either the protrusion was touching the metal frame or the RCA cable was hitting the metal frame where it connects to the amp. They’re both part of the RCA ground so I’m not sure if it was causing a ground loop or what. Either way that fixed my problem. Maybe someone with more electrical knowledge can chime in but that’s what fixed mine FWIW.


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## addissimo (Apr 10, 2007)

Back in my BMW days I had this issue in all of my cars. I tried so many things... so many things...

What ended up taking care of it was to run a ground cable from the head unit to the amps with the RCAs and remote. When I grounded the head unit to the amps, all noise went away. I've done it automatically ever since and haven't had an issue.

I would try your idea of bringing the head unit to the amps to share power/ground to see what happens.


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## LBaudio (Jan 9, 2009)

This is IMHO the most comon reason for ground loops


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## Bmwe39528i (9 mo ago)

Dwarteacher said:


> Here is something radical. Try grounding the amp's body. If I remember right, some amps have an internal chassis ground.
> 
> 
> Here is an Alpine BB1200 with chassis ground. I had no noise issue using it mounted on a board without an external chassis ground. If your amplifier has an internal chassis ground, try an external ground on one screw down point, and see if the noise disappears.


I think my amp body is plastic. How do I go about grounding it? Should I take off the enclosure?


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## Bmwe39528i (9 mo ago)

Selkec said:


> Yes I know this. But you need a oscope to show the ac ripple. If there is a ripple it’s a bad diode. Just measuring and seeing ac with multimeter doesn’t confirm its a bad diode. Most shops have a snapon meter that has the option to detect it


I found this information on a website online:
_A multimeter can read AC voltage and can be used to test for ripple. The alternator should be replaced if AC voltage of more than 50mV is detected (in some cars as much as 100mV is acceptable)._

I did mention that I have a filter installed in front of my headunit, AX-ANR1000, 35 amp filter.
Green wire on it is the input, connected to constant power wire.
Red wire on the filter is the output, goes to the headunit.
If I measure A/C at thr green wire where the filter gets its power, it reads 0.045 volts.
Then I measure on the red wire, which is the output of the filter, and feeds into headunit and provides it constant power, I get 0 volts A/C. Which tells me this filter does clean up the voltage.
The second power wire which goes to the headunit, ignition wire, does not have a filter, and it's also showing around 0.045 volts.

My headunit is only connected with 3 wires. Ground, constant power and ignition power.

For testing purposes, I connected both power and ignition wires on my headunit together and powered them through the output wire from the filter. Same noise is present.

Does this rule out bad alternator diode or should I do another test?


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## nyquistrate (Apr 17, 2011)

Bmwe39528i said:


> I found this information on a website online:
> _A multimeter can read AC voltage and can be used to test for ripple. The alternator should be replaced if AC voltage of more than 50mV is detected (in some cars as much as 100mV is acceptable)._
> 
> I did mention that I have a filter installed in front of my headunit, AX-ANR1000, 35 amp filter.
> ...


So you're getting 45 mV ripple into the headunit. The noise being present even with the filter leans toward running out the alternator.



nyquistrate said:


> You can measure AC with a multimeter.
> 
> OP, what happens with the engine off? Do you still have noise?


Engine off?


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## Bmwe39528i (9 mo ago)

knever3 said:


> Do you have any 12V tools? You could use a battery from one and power your head unit like you mentioned about the charger. Usually chargers are very noisy so might not be the best choice for 12V. Have you tried running a wire from the radio ground directly to the battery negative? If you have a grounding problem that is introducing noise at some point pull the deck so it's not touching any ground of the vehicle and get a speaker wire or any wire that is at least 16 gauge and ground it directly to the battery. You need to find out where the noise is being transmitted through. I don't believe you have a bad deck, but noise is coming from somewhere.


All my tools are dewalt 18 volts. 
So I tried grounding the headunit directly on the grounding wire for the amp. See pictures. Also powered the headunit from the amp power wire.
I think it reduced the problem.
Basically if I only connect rca cables for front speakers in this set up, the whine is gone.
And when I rev rpm, no noise. As soon as I connect even one cable to the amp rear rca plug, I start getting the high pitch noise. But not as loud I believe. If I rev the engine, noise gets worse.
This is if I'm just connecting rca cable to the rear amp plug, not even connecting to the headunit. If I connect to the headunit, noise is still there as well.

Is something shorting the the amp? Rear plugs bad or smth?

I can try grounding headunit on the battery negative instead of amp negative.
















gr


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## ckirocz28 (Nov 29, 2017)

Bmwe39528i said:


> All my tools are dewalt 18 volts.
> So I tried grounding the headunit directly on the grounding wire for the amp. See pictures. Also powered the headunit from the amp power wire.
> I think it reduced the problem.
> Basically if I only connect rca cables for front speakers in this set up, the whine is gone.
> ...


Can your amp run all 4 outputs with just the 2 front rca's connected?


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## Bmwe39528i (9 mo ago)

nyquistrate said:


> So you're getting 45 mV ripple into the headunit. The noise being present even with the filter leans toward running out the alternator.
> 
> 
> 
> Engine off?


Sorry I keep missing this question. With engine off and only ignition on, music is clean. No interference or high pitch noise.


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## Bmwe39528i (9 mo ago)

ckirocz28 said:


> Can your amp run all 4 outputs with just the 2 front rca's connected?


I'm not sure, use some splitters or smth? I posted my amp model, it's Ref704a


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## Bmwe39528i (9 mo ago)

I keep testing.
Only rear rcas connected to the amp, no noise.
Rears and sub, no noise.
Only front rcas to the amp, no noise. Front and sub rcas to the amp, no noise.

As soon as I connect both front and rear rca cables to the amp, I get the whine.

If only front or rear rcas are connected to the amp, with or without sub, sound is crystal clear!

Does this mean something is wrong with the amp??


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## ckirocz28 (Nov 29, 2017)

Bmwe39528i said:


> I'm not sure, use some splitters or smth? I posted my amp model, it's Ref704a


No splitters, what I'm talking about would be a switch that sends front input signal to rear input. But I just read the owner's manual, and, no, you can't do that.
It seems you've effectively ruled out the head unit as the source of the whine and maybe, just maybe, revealed some sort of ground loop involving the rear amplifier inputs.
But you could try some rca y-adapters from the front rca's to all four amp inputs to rule out the rear rca cable being the culprit. Or have you already tried running the front rca's to the rear inputs and found the same noise?


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## Bmwe39528i (9 mo ago)

Yes I tried switching the two extra rca cables, switching them between front and rear rca plugs on the amplifier. So basically both rca cables work.

But the thing is, rears and fronts work fine separately but not together.

So something happens in the amp. Either short between front and rear rca inside amp or bad grounding?


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## Bmwe39528i (9 mo ago)

Tried one more thing. Reversed rca cables. 
Ran rca cables from front inputs on amp to rear outputs on headunits and rear inputs on amp to front outputs on headunit.
Noise is present.
If I disconnect either front or rear rca cables from the amp, noise is gone.
I'm trying to find another amp to test.


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## ckirocz28 (Nov 29, 2017)

Bmwe39528i said:


> Tried one more thing. Reversed rca cables.
> Ran rca cables from front inputs on amp to rear outputs on headunits and rear inputs on amp to front outputs on headunit.
> Noise is present.
> If I disconnect either front or rear rca cables from the amp, noise is gone.
> I'm trying to find another amp to test.


Well that definitely narrows it down. Have you tried running all 4 inputs with your phone and some y-adapters?


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## Bmwe39528i (9 mo ago)

No I didn't know it was possible.
I only had y adapter for my phone and it had 2 rca outputs, not 4.
I just grabbed another amp, lower quality, pioneer GM-A4704. It had 4 channels and it worked well with both rear and front rcas connected. Sub not connected.
So looks like it's the amp...
Gotta return this amp and order another amp.
Not sure if this infinity amp is bad on just incompatible and what to go with now.
Maybe a newer version?


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## ckirocz28 (Nov 29, 2017)

Bmwe39528i said:


> No I didn't know it was possible.
> I only had y adapter for my phone and it had 2 rca outputs, not 4.
> I just grabbed another amp, lower quality, pioneer GM-A4704. It had 4 channels and it worked well with both rear and front rcas connected. Sub not connected.
> So looks like it's the amp...
> ...


That sucks, but at least you narrowed it down to the amp.


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## Bmwe39528i (9 mo ago)

I'm very excited I figured out what's wrong! I appreciate everyone's help here as I know very little about audio and having some ideas was really nice. I've been stuck with this issue for months and finally got it resolved. Just need to figure out what amp to buy and get on with life and enjoy music


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## Bmwe39528i (9 mo ago)

Went with this amp so hopefully it works well when I get it lol 









Pioneer GM-DX874


Limited Edition 4-channel car amplifier — 100 watts RMS x 4




www.crutchfield.ca


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## nyquistrate (Apr 17, 2011)

Bmwe39528i said:


> I'm very excited I figured out what's wrong! I appreciate everyone's help here as I know very little about audio and having some ideas was really nice. I've been stuck with this issue for months and finally got it resolved. Just need to figure out what amp to buy and get on with life and enjoy music


In troubleshooting, be methodical and eliminate all variables.


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## Bmwe39528i (9 mo ago)

Damn it, called it too early. New amp did not solve it, same issue...
This is killing me lol.
I tried again connecting the headunit by the amp, seemed to work OK.
I called a professional audio installer, who came over and tried troubleshooting different solutions.
Basically I refused to understand why I had no whine if I powered the headunit directly from the amp and grounded it directly on the amp.
He poked around and tried different grounds, and did not have anymore success than me.
Only way to reduce or eliminate the whine was to power the headunit, and especially ground it on the amp.
Grounding HU on the amp seemed to effect the biggest change. Using power from the amp appeared to make it even better, but I couldn't tell 100% if that's the case or if I'm hallucinating at this point.
Also when testing the new amp, only using one channel, I.e. channel A or channel B, the noise would go away.
With both channels connected, however, the noise would come back.
So the tech suggested the amp might be the issue.
When I was testing things out before with my friend, who helped me install the system, he would pull out rca cable and plug them back and forth with the car running.
The tech said that doing that could've shorted the amp.
Anyways, it was decided that nothing better can be done than just running a positive and negative from the amp to the headunit to eliminate the problem.
So today I spent all day taking the car apart to run the wires under the carpet.
I thought ok, what a backwards way, but whatever, at least I can listen to music without whine and I don't have to install the headunit by the amp, a ghetto way!
Well, after all the work was done and I connected everything, the whine is ever so strong and present!
I feel so defeated and this ground loop has sent me into a never ending loop myself lol....
I don’t know if I need to buy a third amp now or try connecting the headunit by the amp again to see what happens.

I don't understand where this damn noise comes from....the tech explained to me that it's the alternator grounding itself on the chassis, basically sending excess positive power onto the ground of the car.

I'm ready to do anything at this point to be able to get this whine fixed and finish this project.

I was watching a video






It suggested installing an alternator filter.

I'm not sure if it can help?
Normally I wouldn't care to try, but at a price of $450 I thought I'd double check with you guys.. 

NewMar 150-a 150 Amp Noise Filter NewMar 150-a 150 Amp Noise Filter : Amazon.ca: Electronics


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## Dwarteacher (Oct 17, 2020)

That price is insane, I would not buy that. 

Did you rule out the head unit as the issue?
Did you try to grounding the body of the head unit?
Did you try swapping the amplifier?
Did you separate the rca from the power cable, or do cross runs.

If not try those step before going the route of an overly expensive isolator.
Post picks of your install and wire runs. That would give an idea of how things are installed.


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## Bmwe39528i (9 mo ago)

Yes the price is high, but it looks like a high quality device. I found a cheaper price on ebay. It's 200 usd, plus shipping, taxes, import duties etc. still comes out to over $300 Canadian, but if it has a chance of solving the issue, I don't care at this point...

Yes I tried grounding everywhere in the car, on the negative of the battery in the trunk, on the ground factory stud in the trunk, on the negative under the hood, different grounding points under the hood, drilling a screw hole in the cage under the dash etc.
Tried two headunits. Two amps.
Tried grounding rcas on the headunit, tried grounding the body of the headunit.
I think I'm going in circles now.

At this point I don't care. I'd gladly buy the alternator noise isolator, new alternator from bmw, anything to solve this as the time I've wasted is worth thousands of dollars by now and I'm no further ahead...

I just want to understand where this issue originates and to apply the strongest possible solution to this.


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## Dwarteacher (Oct 17, 2020)

I hear you these things can be frustrating at time, but I assure you that isolator is a bandaid. If your at your wits end, nothing I or anyone can change your mind but I would still like to try. When having a difficult problem the best way to solve it is by process of elimination and break the problem into manageable chunks. You said connect the head unit to that amp ground eliminated the problem at first. That tells me this can be solve. Solving this will require time not necessarily money. Start under the hood clean all ground connections and add a second ground to each. Reroute wire keeping power wire away from rca, make sure rca are twisted and shielded. I know it's frustrating but you can solve this. Pics of your installation may help with ways to solves this. None of us know what your installation looks like and if things are not install well it wouldn't matter how many amp head unit or ground points you use the issue may not go away. See #2 of this thread.








Alternator Whine, Driving Me Crazy


Hey guys. I just recently installed a new system in my car. I am running a Kenwood KDC-BT755HD head unit, Infinity Reference 6030cs in the front and Polk Audio db691 in the rear. They are driven by a JVC KS-AX5104 amp. I have a REALLY bad whine coming from all speakers. This is the setup: - Ran...




www.diymobileaudio.com


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## humandrummachine (May 17, 2010)

Was the alternator and spark wires checked?


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## doeboy (May 2, 2012)

If you havent tried a used alternator from a you pull it that might be a thought. If there is a problem with the alternator creating noise then that would be a better/cheaper solution to try than putting in a filtering device. I typically put a larger cable on the case of the alternator. I don't know if you were checking the actual quality of ground points using a multimeter or not, but that is something which could be helpful and give you objective data on how good the ground is.

It seems really odd that you can connect some rcas and get no noise while when you connect more of them the noise presents. A lot of amps can utilize just 2 channels of input and if you are using the freq filters on the amplifier then I would go that route.


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## Bmwe39528i (9 mo ago)

humandrummachine said:


> Was the alternator and spark wires checked?


Definitely not. I don't know how to test them.


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## Bmwe39528i (9 mo ago)

doeboy said:


> If you havent tried a used alternator from a you pull it that might be a thought. If there is a problem with the alternator creating noise then that would be a better/cheaper solution to try than putting in a filtering device. I typically put a larger cable on the case of the alternator. I don't know if you were checking the actual quality of ground points using a multimeter or not, but that is something which could be helpful and give you objective data on how good the ground is.
> 
> It seems really odd that you can connect some rcas and get no noise while when you connect more of them the noise presents. A lot of amps can utilize just 2 channels of input and if you are using the freq filters on the amplifier then I would go that route.


I heard that all alternators can cause this. Getting a scrap yard alternator would probably make my life more complicated, since I wouldn't even know if it's good or has a problem causing interference as well.
If I'm gonna replace an alternator, then I'll put a brand new one oem, that way at least I know it's a good part. It's also an expensive part so I wanted to see if I can tell, before replacing it, if it's even going to fix it.

I have a multimeter and can check for grounds anywhere. Everything I checked so far, I don't see a problem with grounds. Unless I'm not checking it right.

I'm back at it again.
Right now headunit is located in the front, grounded by a wire directly to the amp.
Constant power comes from the amp positive side, ignition wire is powered from ignition switch.

The whine is present right now with both channels, together or individually.
My amp is obviously 4 channel.

If I have two RCAs connected, the whine is there. If I have four RCAs connected, the whine is there.
If I disconnect all RCAs from the amp, there's no whine. During this time the amp for the sub is connected.

This tells me the problem is not with RCA cables. If they were picking up power noise, whine would be there even with RCAs disconnected from the amp. Also I run my RCA cables from amp to headunit in the middle of the floor, whereas the power wires run on the side of the car.


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## Bmwe39528i (9 mo ago)

If I then disconnect the RCA cables on the headunit, for both channels A and B or one of them, the whine is still there.
Let's say I have two RCAs connected to channel A and two RCAs disconnected on channel B. The whine gets worse if the RCAs on channel B come closer together or closer to the headunit. If I move the disconnected RCAs away from the headunit, whine gets a little bit better. But it's still present.


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## Bmwe39528i (9 mo ago)

I tried following this pdf from crutchfield as well to troubleshoot.


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## Bmwe39528i (9 mo ago)

I completely disconnected the headunit from the system and disconnected all RCAs from the amp. 
Then I plugged one set of RCA cables in channel A. Nothing connected to them on the other end. Then I switch to channel B.
In both situations, I have the stubborn whine.
If I pinch the middle of the rca connector with my fingers, the whine get a lot worse.

So does this mean the whine is coming from the amp?

Can I narrow it down at all? Is it bad amp or bad ground? I'm going to add pictures of the install.


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## SkizeR (Apr 19, 2011)

So you figured out that the noise goes away when you power/ground everything at thr same location, the noise goes away? Congratulations, you just figured out what a ground loop is. You should ALWAYS be powering/grounding everything in the audio system at the same location for this very reason.


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## Bmwe39528i (9 mo ago)

SkizeR said:


> So you figured out that the noise goes away when you power/ground everything at thr same location, the noise goes away? Congratulations, you just figured out what a ground loop is. You should ALWAYS be powering/grounding everything in the audio system at the same location for this very reason.


Well, this was the case before, when I moved the headunit to the trunk of the car, where the battery is located on my bmw.
Now I ran the power and ground wire from the amp to the headunit, and the noise is back.
So I'm back at square 1.
I would love to learn what's going on and how to fix it...


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## humandrummachine (May 17, 2010)

Set your multimeter to 0.00 or .000 VAC and measure between your alternator positive and battery negative. If you have too much AC voltage then your alternator has an issue. 

My '99 Dodge 3500 had this issue and the AC voltage was measurable with a $20 multimeter, something around 0.1 or 0.2 VAC and was almost zero after a new alternator. It caused the transmission to go in and out of overdrive.


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## Bmwe39528i (9 mo ago)

Picture 1, it's the big 0 gauge copper positive wire powering the amps. I power it directly from the battery.
The two small wires that you see on positive and negative is just for a battery maintainer.

Picture 2 is the same wire going up and a fuse.

Picture 3 is the same blue power wire going into the cutout in the trunk cover.

Picture 4 is the ground stud. Cleaned well to shiny metal. Two ground wires connected to it.


Picture 5 shows where both ground wires go. Thicker black wire goes to ground both amps.
The gold looking ground cable goes into a disconnecter box I installed just in case I need to disconnect the battery without removing battery clamps.
So the negative cable from the battery goes to the disconnect box. And then the gold ground wire goes to ground in the trunk from the disconnect box.

On picture 6 you see the disconnect box. You also see positive 0 gauge wire splitting into 2, to power the amps.
You also see the negative 0 gauge wire splitting into 2 ground for both amps.

Picture 7 shows the power wire splitting.

Picture 8 you see the capacitor.
One positive wire goes to power the capacitor and the other positive to power the amp for the sub.
In the same fashion the negative wire splits into two, where one wire goes to ground sub amp and the other negative goes to the capacitor.
Then from the capacitor, power and ground goes to the main amp for the speakers.

You will also see a double strand wire on the positive stud of the capacitor. This one goes to power the headunit.

Still on picture 8, on the most left side on the amp, where the negative wire from the capacitor goes, you see a smaller gauge wire coming out. That's the wire that goes to the ground for the headunit.

Picture 9 is just the sub amp and shows a bit more of the installation.

Pictures 10, 11, 12 just shows some more angles of the install in the rear of the vehicle.


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## Bmwe39528i (9 mo ago)




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## Bmwe39528i (9 mo ago)

humandrummachine said:


> Set your multimeter to 0.00 or .000 VAC and measure between your alternator positive and battery negative. If you have too much AC voltage then your alternator has an issue.
> 
> My '99 Dodge 3500 had this issue and the AC voltage was measurable with a $20 multimeter, something around 0.1 or 0.2 VAC and was almost zero after a new alternator. It caused the transmission to go in and out of overdrive.


My alternator has a plastic cap on the positive stud so I have to put in there an extra wire and then measure positive from that wire.
As a negative at first I used alternator body and then tried different grounds under the hood.
So when I started the car, the reading started at around 0.128v and within minute dropped for 0.075v.

I disconnected the negative probe from the body of the alternator and then the AC reading stayed about the same, between 0.060 and 0.070V even with the negative disconnected.

As soon as i connected the negative people to grounds under the hood, it jumped to 0.151V.

Then I reached inside the vehicle and connected negative probe to the ground wire that I ran from amp ground to headunit ground. It was showing around 0.130V.
I couldn't reach the battery negative right on the battery.

Then just in case I used a spare 0 gauge copper wire and ran it from the battery negative to the front of the car, where I could reach the negative terminal of the multimeter.
It measured 0.130V


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## Bmwe39528i (9 mo ago)




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## Dwarteacher (Oct 17, 2020)

Now things are making sense. First the wired need to be organized. Power wire need to separate from the rca. From the look of the picture it seems like the ground wire is bolted on top of sound deadener. If so remove it sand the area to be grounded to bare metal. Your install need work. Fix the install you will fix your noise issue. Take your time to ensure it's done right.


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## humandrummachine (May 17, 2010)

Sounds like


Dwarteacher said:


> Now things are making sense. First the wired need to be organized. Power wire need to separate from the rca. From the look of the picture it seems like the ground wire is bolted on top of sound deadener. If so remove it sand the area to be grounded to bare metal. Your install need work. Fix the install you will fix the ground loop.


^Agreed.

OP what ground bolt even is that? Appears to have yellow paint.

Also the AC voltage does appear to be high. Did you say you have noise with the motor off?


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## Bmwe39528i (9 mo ago)

Which power wire do I need to separate from rca? 
Ground wire is not on top of the deadening. The metal stud where the ground wire is grounded is super shiny, clean and sanded. You just don't see it because of the ground wire terminals and nut on top.
Of course I wouldn't just bold the terminals on top of deadening  the deadening is around the ground stud


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## Bmwe39528i (9 mo ago)

humandrummachine said:


> Sounds like
> 
> ^Agreed.
> 
> ...


It's a factory ground stud. Welded to the trunk from factory.
There's no yellow paint. If you zoom in, the yellow paint is on the outside of the nut, so it's irrelevant.
The ground stud and both terminals are all shiny and clean bare metal.

The whining is only present with engine running and follows the rpm, hence I call it the alternator whine.
Maybe AC voltage is a bit high, but when I measure AC on the wire that feeds the amp or the headunit, AC voltage reads 0. So maybe AC is high at the alternator, but it's 0 where it powers the amps and the headunit.

I'd be happy to change the alternator if I could confirm it's causing issues.


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## Dwarteacher (Oct 17, 2020)

You have a pot of spaghetti on the boil, it's hard to make head or tail of what going on. You need to get things organized and wire ran and terminated correctly. If you want to fix this issue you absolutely have to fix the install. If you use Facebook join the 12 volt clean wire club for ideas how to do it correctly or check out some of the build logs on the forum.


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## humandrummachine (May 17, 2010)

You could look into rebuilding it or changing out the diode pack yourself. It sounds like you have over 100mV of AC ripple coming from the alternator, which in my case was enough to find its way into the PCM and mess up transmission shifts.


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## humandrummachine (May 17, 2010)

I'd ditch the capacitor and any other unnecessary equipment to clean up the install.


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## NW JLUR (Dec 3, 2018)

Dwarteacher said:


> From the look of the picture it seems like the ground wire is bolted on top of sound deadener.


A better option would be to run your amp ground wires directly to the battery terminal. 
Have you tried bypassing the cap on the power wire? When I was troubleshooting install problems I’d start from one end and work towards the other. Start at the battery ground, battery terminal, ground one amp directly to the battery, then the other, then add the cap, etc… testing after each single change you make.


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## NW JLUR (Dec 3, 2018)

Another problem, although not very common, could be corrosion inside a wire, most likely under the hood.


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## Bmwe39528i (9 mo ago)

Dwarteacher said:


> You have a pot of spaghetti on the boil, it's hard to make head or tail of what going on. You need to get things organized and wire ran and terminated correctly. If you want to fix this issue you absolutely have to fix the install. If you use Facebook join the 12 volt clean wire club for ideas how to do it correctly or check out some of the build logs on the forum.


Well it's a pretty basic install. Doesn't look nice but it's not that hard to make sense of what's going on at all.
I understand what you mean and visually it'd look nice and clean and neat. And I will do it once I fix the issue. At this point I need to be able to move the sub and amps from the trunk to the rear seat and back, if I need to get into the battery compartment in the trunk.
So I need some slack in wiring.
I understand these pictures look nice

















But before I secure everything for good, I need to get the alternator whine resolved.
Whether the wires are laying around or are neatly ziptied together doesn't really change anything in terms of functionality. 
I can't zip tie everything properly to the perfect length at this point. I don't know if the amp is bad, wiring, rcas etc....I can make the wires look nice for pictures, and then if the problem doesn't go away, I'd have to rip everything apart again. If i need to change the amp ill have to rewire a bunch, if my RCA cables are bad I'll have to rip everything apart to take it out. 
This is not a permanent install, once I figure out the problem I'd gladly make it look clean.
I need slack in wiring to be able to move stuff around. My install is not that complicated. There's wires going to speakers and just because they're not ziptied doesn't change anything other than aesthetics.


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## Bmwe39528i (9 mo ago)

NW JLUR said:


> A better option would be to run your amp ground wires directly to the battery terminal.
> Have you tried bypassing the cap on the power wire? When I was troubleshooting install problems I’d start from one end and work towards the other. Start at the battery ground, battery terminal, ground one amp directly to the battery, then the other, then add the cap, etc… testing after each single change you make.


I tried grounding the amp directly on battery negative, without success.
The capacitor was installed recently, as someone suggested it could help. It didn't do anything. Didn't make it better or worse.
If you guys insist, I can get rid of the capacitor.
I'd like to start at one end and start working toward the other end, but the whine is there to begin with. I tried everything I can think off and everything that was suggested in this thread.
I don’t know what wire under the hood would have corrosion inside of it. I'd be happy to check. All the wires I've seen, and I've replaced everything under the hood except for the engine, I didn't find any corroded wires.

As for the alternator, I'm gonna try and find out from other bmw X5 E53 owners if my AC voltage is abnormal. Still, AC voltage is 0 where my amp and headunit are powered, even if I revv the engine. What's why I dont understand how this AC from the alternator would cause problems if it's not making it to the amp.


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## yobbo7 (9 mo ago)

There’s a lot of suggestions here, some good and some not so good. It’s very likely you have a non-zero potential between your head unit ground reference and amplifier circuit ground. You can find the reason and fix it, but if you just want to be done with it, try an audio isolation transformer. Unless it’s radiated pickup, something like this will almost certainly fix your problem. Not cheap for a good one like Jensen, but will probably work. Not sure if you can try and return if it doesn’t work, but it’s worth a shot. 









Home


Jensen Iso-Max CI-2RR RCA Stereo Line Input Isolator Hum EliminatorUse the CI-2RR to remove ground-loop hum from unbalanced stereo signals in virtually any sound application. With high quality RCA cables, connect the CI-2RR between your source device (cable or satellite set-top box, audio...




www.parts-express.com


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## Bmwe39528i (9 mo ago)

_It’s very likely you have a non-zero potential between your head unit ground reference and amplifier circuit ground. You can find the reason and fix it, but if you just want to be done with it, try an audio isolation transformer._

I would love to find and fix it, if only I knew how  I've exhausted all my knowledge and what I could find on the internet.
You say there's non-zero potential between headunit and amplifier ground.
In this case, what I don't understand, why do I have alternator whine even if the headunit is completely removed the the equation? I.e. all RCAs and power plug disconnected. But noise goes away if I disconnect the RCA's from the amp. Basically even connecting one set of RCA's into the amp introduces whine, even if the other end of RCA's is not connected to anything.

And I just tried one more time, moving the headunit to the back of the car, on back seat where the amp and sub are located, and powering and grounding headunit on the amp, eliminates 80-90% of the whine.
Yet if I put the headunit in the front by the dashboard, also grounding and powering it from the amp, the noise is there. Maybe something wrong with the RCA cables under the carpet. Because when I move the headunit to the back, I use different RCA cables, since the ones under the carpet won't reach all the way to the back from the dash.
I'll try a few more configurations with RCA cables.
I think I have quality RCA cables but I wouldn't mind to try another set. Reading on the internet people suggested "twisted pair" and "triple insulation", but I'm not sure what would be best RCA set to buy.

This audio isolation transformer you mentioned, do I connect it between the amp and rca cables or between headunit and rca cables?
Since I have 4 channels, do I need to buy two of these transformers?


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## NW JLUR (Dec 3, 2018)

Bmwe39528i said:


> And I just tried one more time, moving the headunit to the back of the car, on back seat where the amp and sub are located, and powering and grounding headunit on the amp, eliminates 80-90% of the whine.
> Yet if I put the headunit in the front by the dashboard, also grounding and powering it from the amp, the noise is there.


When you move the head unit to the front can you use the same rca cables you used in the back? If not, get a new pair that will reach from front to the amps. Test them in the back with the head unit, then move it to the front. Keep the head unit powered off the amp. There’s possibly a few things contributing to the noise. 
I’d permanently move your amp ground to the negative of the battery, connect a power and ground wire for the head unit to the battery. 
Here’s a link I found to a BMW form where a battery wire corroded in the middle. I’d ask in a few BMW forums if anyone with your model has had problems with noise.


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## Dwarteacher (Oct 17, 2020)

Bmwe39528i said:


> _It’s very likely you have a non-zero potential between your head unit ground reference and amplifier circuit ground. You can find the reason and fix it, but if you just want to be done with it, try an audio isolation transformer._
> 
> I would love to find and fix it, if only I knew how  I've exhausted all my knowledge and what I could find on the internet.
> You say there's non-zero potential between headunit and amplifier ground.
> ...


The most common reason for unwanted noise in a car audio system is bad installation.
Fix your installation and 9 out of 10 you will fix your issue.
Good luck


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## yobbo7 (9 mo ago)

Bmwe39528i said:


> _It’s very likely you have a non-zero potential between your head unit ground reference and amplifier circuit ground. You can find the reason and fix it, but if you just want to be done with it, try an audio isolation transformer._
> 
> I would love to find and fix it, if only I knew how  I've exhausted all my knowledge and what I could find on the internet.
> You say there's non-zero potential between headunit and amplifier ground.
> ...


So, I may have misunderstood your problem. You are getting noise if you just have RCA cables hooked up to the amp and nothing else? How long are the cables and are they still routed to the head unit?

If you try the transformers, having 4 channels you would need 2 if they are the stereo boxes, yes. I would probably buy the one channel or two channel unit and test it. I would put it right at the amp. A transformer should have extremely high common-mode noise rejection. For RCA cables, if you aren't using the transformers then get a coaxial style cable. If you are using the transformers you might get a slight benefit in rejection with a twisted pair construction.


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## Bmwe39528i (9 mo ago)

Yes correct, noise is there even if I just plug an extra set of rca cables and lay them on the floor or anywhere else. I tried moving them around and the noise is there. If I pinch the ends of rcas cables with my fingers, the noise gets worse.


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## humandrummachine (May 17, 2010)

Pinch the ends?


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## Bmwe39528i (9 mo ago)




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## yobbo7 (9 mo ago)

That doesn't mean a whole lot really. If your amp has a high input impedance it is quite easy to pick up all kinds of stuff. You probably have a grounding issue in the car. The transformers might work though, even if it is a band-aid.


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## Bmwe39528i (9 mo ago)

NW JLUR said:


> When you move the head unit to the front can you use the same rca cables you used in the back? If not, get a new pair that will reach from front to the amps. Test them in the back with the head unit, then move it to the front. Keep the head unit powered off the amp. There’s possibly a few things contributing to the noise.
> I’d permanently move your amp ground to the negative of the battery, connect a power and ground wire for the head unit to the battery.
> Here’s a link I found to a BMW form where a battery wire corroded in the middle. I’d ask in a few BMW forums if anyone with your model has had problems with noise.


Yes, believe it or not, if I move the head unit to the back of the vehicle and connect it to the amp/capacitor for power/ground, there's barely any whine. I'll attach a picture. 
I mean the whine is so small that I have to rev the engine many times to see if I can discern any whine at all. I'm not even sure if the whine is there. It's tiny and I'd be very happy if that's what I had.









Now if I run the positive and negative from the same source, using the same RCAs, to the dash, the whine appears. So basically all that changes, the headunit moves from the rear seat to the front seat/shifter area, and the cables for positive and negative get longer from 1 foot to maybe 3-4 feet.
Having the headunit in the back is the only instance so far where I was able to have no whine, or at least minimal whine where it wouldn't bother me.
I saw your link with a corroded wire. My alternator wire that goes to the positive battery cable is not corroded. I have examined it.

I can try grounding the amp on the battery negative instead of the body, as you suggested. I've tried it before and it produced 0 result.
What I didn't try is to power the headunit directly from the battery and ground the headunit on the battery itself. I can try that.


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## humandrummachine (May 17, 2010)

^that might reduce noise if it's your alternator because I've read that batteries soak up AC ripple.

If your alternator has a plug in it that tells it to charge, you unplug it and see if there is noise.

Could be spark plugs or even some radio frequency interference like with mobile cb/ham radios


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## Bmwe39528i (9 mo ago)

_So, I may have misunderstood your problem. You are getting noise if you just have RCA cables hooked up to the amp and nothing else? How long are the cables and are they still routed to the head unit?_

Yes I have alternator whine even if RCA cables are connected to the amp and not connected to the head unit on the other end.
The RCA cables are maybe 10 feet or so.
The noise is there, no matter how the cables are routed. Whether they are laid on top of the carpet toward the headunit, or whether they're laying by the amp. The whine is there.

_If you try the transformers, having 4 channels you would need 2 if they are the stereo boxes, yes. I would probably buy the one channel or two channel unit and test it. I would put it right at the amp. A transformer should have extremely high common-mode noise rejection. For RCA cables, if you aren't using the transformers then get a coaxial style cable. If you are using the transformers you might get a slight benefit in rejection with a twisted pair construction._
These are the cables I have right now. They're run under the carpet. Than I have 3 sets of cheaper rca cables laying around that I use as well. The cables under the carpet, I can't use them when I'm moving the headunit to the rear of the car. They won't reach cuz they're attached underneath the carpet.








FosPower (1.8m / 6ft) 2 RCA M/M Stereo Audio Cable [24K Gold Plated | Copper Core] 2RCA Male to 2RCA Male [Left/Right] Premium Sound Quality Plug : Amazon.ca: Electronics


FosPower (1.8m / 6ft) 2 RCA M/M Stereo Audio Cable [24K Gold Plated | Copper Core] 2RCA Male to 2RCA Male [Left/Right] Premium Sound Quality Plug : Amazon.ca: Electronics



www.amazon.ca





By transformers you mean the Jensen units?
I haven't ordered them yet. Some people say they won't help in my situation.

I'm not sure what's the highest quality RCA cables. If you can recommend any, I'd definitely buy them


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## Bmwe39528i (9 mo ago)

humandrummachine said:


> ^that might reduce noise if it's your alternator because I've read that batteries soak up AC ripple.
> 
> If your alternator has a plug in it that tells it to charge, you unplug it and see if there is noise.
> 
> Could be spark plugs or even some radio frequency interference like with mobile cb/ham radios


I'll give it a shot and report back. Unfortunately my alternator doesn't have a plug for charging. I mean, I can disconnect the main power wire going to the alternator?

I dont know about radio. I deleted radio wiring from my car.

I can change spark plugs and spark plug wires. Any specific brand you recommend?


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## yobbo7 (9 mo ago)

Bmwe39528i said:


> _So, I may have misunderstood your problem. You are getting noise if you just have RCA cables hooked up to the amp and nothing else? How long are the cables and are they still routed to the head unit?_
> 
> Yes I have alternator whine even if RCA cables are connected to the amp and not connected to the head unit on the other end.
> The RCA cables are maybe 10 feet or so.
> ...


Yes I mean the Jensen units. Even if it’s not a ground loop, good transformers give incredible common mode rejection. If you can return them they are worth a try especially if you are considering things like replacing spark plugs and wires.

I don’t think any RCA cable specifically will help here unless the ones you have are physically damaged.


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## NW JLUR (Dec 3, 2018)

Bmwe39528i said:


> Yes, believe it or not, if I move the head unit to the back of the vehicle and connect it to the amp/capacitor for power/ground, there's barely any whine. I'll attach a picture.
> I mean the whine is so small that I have to rev the engine many times to see if I can discern any whine at all. I'm not even sure if the whine is there. It's tiny and I'd be very happy if that's what I had.
> View attachment 335521
> 
> ...


I think the corroded cable was under the car from the battery to the front. It sounded like it was close to an exhaust pipe that caused corrosion in the middle of the cable.


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## Bmwe39528i (9 mo ago)

yobbo7 said:


> Yes I mean the Jensen units. Even if it’s not a ground loop, good transformers give incredible common mode rejection. If you can return them they are worth a try especially if you are considering things like replacing spark plugs and wires.
> 
> I don’t think any RCA cable specifically will help here unless the ones you have are physically damaged.


Well looks like I'm at a dead end again  I'm ordering these Jensen units then. I guess they're good to have in any system...


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## Bmwe39528i (9 mo ago)

NW JLUR said:


> I think the corroded cable was under the car from the battery to the front. It sounded like it was close to an exhaust pipe that caused corrosion in the middle of the cable.


Yeah I looked at the pictures, it was older bmw design, I think maybe e30 or e34. E53 has the power cables inside the car. The only outside cable is a ground cable connecting the engine block to the chassis. I clean the cable terminals and the studs where it's attached with a power brush, so I know there's no issue there.


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## sprexumn (Sep 28, 2005)

I haven’t read the whole thread just skimmed but here are some thoughts:


The thicker the ground wire star-connecting the front head unit and the rear amps the better. Try 4wag or thicker to experiment. Connections must be tight: zip tying a ground cable is not a valid test as shown in the photo in this post Alternator whine is killing me, months without soluton...
The thicker the conductors in the RCAs the better; I use Canare L4CFB cable for critical signals because the solid center conductor is thicker than other brands, and their RCA crimp ends have gold plating. 
The picture of the rca you are squeezing looks awfully corroded. Replace that RCA. Alternator whine is killing me, months without soluton...
Toslink optical cables from head unit to dsp in amp rack would be a foolproof way to isolate a head unit, even though it would require expensive changes to your system. 
Keep your amp gains low: for testing whine, just high enough to listen at a decent level.


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## Bmwe39528i (9 mo ago)

Thanks for your thoughts. I've been advised on another forum that the noise is most likely caused by spark plugs and ignition coils. I ordered a set.

Can you provide links to your recommended products? I'm not sure of specific models, but based on my Google search they don't seem to fit?


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## doeboy (May 2, 2012)

Will be interested to hear about how things play out. Let us know.


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## Bmwe39528i (9 mo ago)

Getting denso sparkplugs and ignition coils tomorrow. Will start with that. Then alternator noise filter and Jensen transformers arriving in about a weel


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## Bmwe39528i (9 mo ago)

I didn't realize I only ordered spark plugs and boots, did not get ignition coils.
Changing boots and spark plugs didn't do anything...
There are not Denso ignition coils.
I heard Bosch is garbage.
So choice was between Bremi and Delphi. I think bmw oem switched from Bosch to Delphi due to problems. And the coils I have right now are Bosch, which makes me think they could be bad. Who knows.
I'll should get Delphi by the weekend and try them. The Jensen transformers and alternator filter are gonna be here soon too.


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## Bmwe39528i (9 mo ago)

Installed new ignition coils. Whine still there..


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## humandrummachine (May 17, 2010)

Did you install factory OEM spark plugs?


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## Bmwe39528i (9 mo ago)

DENSO 5304 Spark Plug | RockAuto


RockAuto ships auto parts and body parts from over 300 manufacturers to customers' doors worldwide, all at warehouse prices. Easy to use parts catalog.




www.rockauto.com






These are the ones I installed, denso 5304


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## M_Mark28 (Mar 11, 2021)

I kinda skimmed through the thread, but did you try a different head unit up front ? Ive always had alternator whine and always thought it was the amp or ground loops. It was actually the head unit. I was running a Kenwood as well, switched to a pioneer deh-p01 and than two different denon dct-r1's. Dead quite on all three.


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## humandrummachine (May 17, 2010)

Bmwe39528i said:


> DENSO 5304 Spark Plug | RockAuto
> 
> 
> RockAuto ships auto parts and body parts from over 300 manufacturers to customers' doors worldwide, all at warehouse prices. Easy to use parts catalog.
> ...


those should be fine since they are resistor type. I forget, did you check for ac voltage ripple, if so what was the value?


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## Bmwe39528i (9 mo ago)

M_Mark28 said:


> I kinda skimmed through the thread, but did you try a different head unit up front ? Ive always had alternator whine and always thought it was the amp or ground loops. It was actually the head unit. I was running a Kenwood as well, switched to a pioneer deh-p01 and than two different denon dct-r1's. Dead quite on all three.


Yes I tried two different units, both Kenwood.
How I know it's not the headunit, the noise is there if the headunit is not even connected. Plugging rcas into the amp is enough for noise to be there, especially both rca channels. Sometimes if it's only one channel, the noise is almost gone.


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## Bmwe39528i (9 mo ago)

humandrummachine said:


> those should be fine since they are resistor type. I forget, did you check for ac voltage ripple, if so what was the value?


I don't know how to check for ripple, so I checked as I was told, by measuring A/C voltage. There was some A/C, but if I used a filter, the A/C voltage was 0. Some people say measuring A/C is not really the way to do it


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## Bmwe39528i (9 mo ago)

I guess I'll take the belt off just to triple confirm noise is directly related to the alternator.


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## humandrummachine (May 17, 2010)

Is there some kind of device that could be emitting radio interference nearby or in the car?


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## Bmwe39528i (9 mo ago)

Nothing emitting interference. Actually I removed the radio module responsible for radio signal pick up. So even if I wanted to, no radio in the vehicle


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## humandrummachine (May 17, 2010)

Still seems like some kind of alternator interference or a ground issue. Hard to say. Let us know what happens when you try it without the belt. I was reading that some of these vehicles have water cooled alternators (?)


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## humandrummachine (May 17, 2010)

Bmwe39528i said:


> My alternator has a plastic cap on the positive stud so I have to put in there an extra wire and then measure positive from that wire.
> As a negative at first I used alternator body and then tried different grounds under the hood.
> So when I started the car, the reading started at around 0.128v and within minute dropped for 0.075v.
> 
> ...


That 0.130Vac is probably the problem. It sounds like there is AC ripple between the alternator + and battery - in your trunk which I'm assuming is your amplifier ground. I'd bet it's backfeeding AC right into your amp.


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## Bmwe39528i (9 mo ago)

humandrummachine said:


> Still seems like some kind of alternator interference or a ground issue. Hard to say. Let us know what happens when you try it without the belt. I was reading that some of these vehicles have water cooled alternators (?)


Bigger 4.4 engines haves water cooled alternators but mine is 3.0, just a normal alternator. Instead of removing the belt I disconnected a connector and red cable wire.
The noise was gone right away. Nothing really new here, just confirms the issue is coming from alternator.


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## Bmwe39528i (9 mo ago)

humandrummachine said:


> That 0.130Vac is probably the problem. It sounds like there is AC ripple between the alternator + and battery - in your trunk which I'm assuming is your amplifier ground. I'd bet it's backfeeding AC right into your amp.


I have a feeling you might be right. This for the first time makes sense for me. All other suggestions never made total sense. But this explanation makes *perfect* sense.
And this also explains why the power filter on ignition wires did nothing.
Yes they filtered the ripple out of ignition wires to power the headunit, but that did little for the amp and battery. The main power cable from the alternator still carried ripple...I just thought this number was too low to affect anything, because when I posted my A/C measurement results, no one said it was a problem. So I assumed it was fine.
But with my limited understanding of electricity, I couldn't exactly figure it out. 
This is what I've been told:

_The "whine" is caused by the alternator grounding out on the chassis, all vehicles do it, German cars are just more prone to it. They try and ground out every module on them. So in return your aftermarket stereo picks up the whine . Your factory stereo in that x5 should have been grounded through its amplification system. And by saying your alternator grounding out, I mean when the rectifier inside the alternator sees that it does not need anymore charge in the battery or electrical system, it grounds it out, that power needs somewhere to go. There's not much more you can really do._

So my understanding is that excess positive power from the alternator is being grounded on the alternator but maybe it's too much power for the ground, and the excess positive power ends up polluting the ground. That's why no ground in the vehicle gets rid of the whine. Hence the loop.. 

Well with the new 150 amp power filter directly after the alternator, it might do the trick!!

I guess it will completely clean up and eliminate ripple (A/C). Buy I don't know if alternator would still be producing excess DC that would pollute my ground.

Will find out soon, but I feel we're closer to a solution here Ordered the damn thing on June 1st from USA and still waiting...


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## humandrummachine (May 17, 2010)

I don't follow that. I think you need a new alternator and nothing else.


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## Bmwe39528i (9 mo ago)

humandrummachine said:


> I don't follow that. I think you need a new alternator and nothing else.


Hmmm, are there AC/ripple specs for the alternator? I mean, what should the alternator A/C reading be?
To be able to tell if my alternator bad or not?
I heard all alternators have some ripple, but what's the acceptable range, I don't know.
Well I'll get the alternator filter this week I'm hoping and see if it helps. If not, I guess I'll put in a new alternator. How much I've spent on this car so far, another $500 will just be a drop in the bucket😂
And if that doesn't fix it, I'll look up some magicians on Craigslist!


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## humandrummachine (May 17, 2010)

Around 50mV (0.050 V) is acceptable. I just measured my car and once it ran for a minute or two the AC voltage rested around 0.010 to 0.030 Vac.

Maybe ask someone with your same car to measure their alternator AC to double check.


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## Bmwe39528i (9 mo ago)

Thanks for doing this! Yes I've asked on bmw x5 forum but haven't gotten any luck yet, people are saying it's not the alternator, or that AC voltage is not a good indicator and I should be measuring with an oscilloscope, which I'm not opposed to, just don't know what and how to measure. I guess I can do some research on that. So nobody measured alternator AC yet.

I'm eager to try out this 150 amp alternator noise filter.

I also hear that people install an extra filter of 25 amps right next to the components, to clean up interference even more.
So I consider buying Newmar PC-25 as well, but I don't get how they connect these filters to the amp, for example.
I mean I understand the headunit, the power wire for the headunit is so small. But for the amp, it's gauge 4, while the wire for 25-30 amp noise filter looks to be 16-18 gauge.
I mean, am I supposed to transition from gauge 4 wire and connect to it such a small gauge as 16-18 to it? Would it not be a problem, given there's a reason 4 gauge wire is used to power amps. Wouldn't 16-18 gauge be too small? I mean, why isn't the amp powered by 16 gauge wire if that's enough?


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## humandrummachine (May 17, 2010)

IMO you're really going the wrong direction by considering all these filters. Voltage is "everywhere" so to speak so your ground wires could be causing issues. Are people regularly putting filters on every single power and ground? No. Are you supposed to transition 4awg to 16awg? Absolutely not. 

Do some research and watch some videos on AC ripple tests. Information is readily available. I cannot guarantee its your issue but your alternator is way out of spec and probably has a bad diode. 

You also have great advice to clean up your installation and remove unnecessary components. 

Let us know what happens with the belt off.


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## Bmwe39528i (9 mo ago)

I'll start learning about oscilloscope and ripple.
Just wondeing what's the point taking the belt off if I already disconnected the power wire from the alternator and the noise was gone?
Aren't both tests, removing the belt and disconnecting power wire, accomplish the same task? I.e. take alternator out of equation?


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## humandrummachine (May 17, 2010)

I forgot that you disconnected the power wire and it removed the noise, so yeah no belt removal test is necessary and its essentially proven that your alternator is putting out electrical interference.


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## Bmwe39528i (9 mo ago)

I knew it had to do with the alternator, as the whine followed the rpm. I guess the alternator may or may not be defective. I did get some private messages with great advice and support, I'll share one of them with author's permission! It just goes to show that even a new alternator may not solve the problem. In this case, a device similar to mine,
Helix Cap 33 - alternator noise suppressor, fixed the problem!


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## humandrummachine (May 17, 2010)

I thought you already had a capacitor installed.


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## Bmwe39528i (9 mo ago)

That's the thing. I have a capacitor. And I thought his was a capacitor is as well.
But his device, Helix Cap 33, is actually not a capacitor in the same sense. It's actually an alternator filter, that gets installed at the alternator.
Basically Helix Cap 33 is almost the same device as the one I purchased, NewMar 150A.

I will install it hopefully by Friday and will give an update! I'm pretty excited and hoping it will finally work!


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## Bmwe39528i (9 mo ago)




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## Bmwe39528i (9 mo ago)

Geez just when I thought I'd have some luck, it almost burned down the car!
I don’t get it...


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## Speedhunter (Feb 21, 2020)

6 pages and than ^this kind of wiring pops up....


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## humandrummachine (May 17, 2010)

Steadily getting worse... please make sure all of the +12V wires are fused. Then remove all of this unnecessary stuff like capacitors, noise filters, etc. Only head unit, fuse, amp, speakers. Then clean up and organize all of your wiring and report back.


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## Bmwe39528i (9 mo ago)

Literally all I did was disconnect alternator wire, connect it to "battery" on noise filter, then add an extra 0 gauge wire and connect it from the alternator to "alt" on the noise filter. Then grounded the noise filter uner the hood.
Then turned on the battery disconnect switch and tried to start the car and it wouldn't even crank or anything, dashboard lights off. And then I started smelling burning...


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## JohnnyOhh (Feb 19, 2015)

dude, i think you grounded the battery somehow. 
does that wire that is burned... go to the noise filter??
be careful! maybe you need to re-check the schematic to make sure things are hooked up correctly.


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## Bmwe39528i (9 mo ago)

Capacitor seems fine. Basically the ground wire that goes from disconnect switch to the ground point in the car melted really bad.
And then under the hood, where the positive wire from the battery connects to the positive wire going to the starter (where you see the smoke). Then from starter it goes to alternator.
Literally the only variable I changed was this alternator filter.
Well back to the drawing board🙈


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## humandrummachine (May 17, 2010)

Like watching a bad horror movie. No, don't walk into the dark spooky woods, no!


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## Bmwe39528i (9 mo ago)

Haha lol, I replaced the burnt wires and disconnected the amp power and ground.
Car started and ran fine.
I connected power for the sound system, and as soon as I tried to ground the sound system, it made a loud pop noise and a black mark on the battery negative terminal. I think there's a short somewhere, somehow.
I'll start by removing the capacitor by the amp...and calling my house insurance 🤣


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## Bmwe39528i (9 mo ago)

Well I was thinking what could've gone wrong while out for a movie...and the only problem I could think of was the boss capacitor
BOSS Audio Systems CAP8-8 Farad Car Capacitor for Energy Storage to Enhance Bass Demand from Audio System https://a.co/d/7Zw3gKO

Well sure as hell, it must've shorted out! Positive and negative of the capacitor showed 0 resistance.
So obviously everything was shorting....
Took out the capacitor, everything is working, nothing is melting, car running, music playing.

Now I can't tell if the whine is there or not.
Maybe my brain is fried a bit lol. But I'm not sure if the noise is the same whine or maybe just whisling from disconnected air ducts under the hood.
So I disconnected the sound system by removing the main negative wire from the battery and started the car again.
Now with both amps off, obviously speakers had no power from the amp, the noise is still there. Even with all rca cables disconnected from amp and headunit, the noise is there lol.
I don't know if the whine disappeared and I'm just hearing the engine noise or what.

Definitely now is not like before. Maybe that alternator filter worked. Now noise is the same with either sound system on or off.
I forgot I should've put my ear next to the speakers/tweeters to determine if the noise is coming from them, because that's where it was coming from before. 

Before, there was a distinctive difference if I disconnected rca cables from the amp. Not anymore.
Can speakers pick up noise even if amps and headunit have no power?

I'm gonna ask my friend to swing by tomorrow so we can listen together...


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## LBaudio (Jan 9, 2009)

check the mail👓


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## OGJordan (Sep 26, 2006)

From just reading your post and no response first thing I’d say is “the metal bar under the dash” is most likely a poor ground for the headunit. I’d move that. Some pioneers back a few years needed the rcas grounded, do a search on that


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## Bmwe39528i (9 mo ago)

LBaudio said:


> check the mail👓


48 files with 2GB of data, that must be lots of pdfs man!! I'll need to get to my computer before I download it


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## Bmwe39528i (9 mo ago)

OGJordan said:


> From just reading your post and no response first thing I’d say is “the metal bar under the dash” is most likely a poor ground for the headunit. I’d move that. Some pioneers back a few years needed the rcas grounded, do a search on that


I've since changed the ground multiple times, directly to the battery and to amp ground.
I tried grounding all rca ports on the headunit without success as well


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## Bmwe39528i (9 mo ago)

I did some more testing. Whine is still there.
The alternaror filter filter must be working though.

If I measure AC before the filter, it's showing 0.227. Right after the filter, it's 0.116.
If I measure on the battery terminals, it's 0.017

The one thing I noticed, if I touch the body of the headunit with a ground when it's running, the noise gets way worse.

I disconnected the headunit connector and rcas. So just left 4 rcas in the amp for speakers, and the noise is there.
Basically I'm getting noise into speakers and tweeters with no HU connected.
If I disconnect 2 rcas from channel A or channel B, the noise decreases. This is the same behavior as was happening when I started this thread.
If I touch the rca cables on the side that goes to headunit, the noise gets worse.

In this case it must be either the amp or the cables, or still some ripple noise that they pick up?


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## NW JLUR (Dec 3, 2018)

Have you tried adding new grounds up front from the engine block to body? Are the amplifiers mounted to metal? If they are have you tried removing the screws and make sure they aren’t touching metal?


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## Bmwe39528i (9 mo ago)

I tried adding new grounds. Both amps are mounted to a wooden sub box.
I tested resistance between all grounds, resistance is 0 between battery negative cable and ground point in the trunk. Also 0 between trunk ground wire and ground on both amps and headunit ground.
I tested resistance on speaker wires as well, it's between 0 and 0 omhs. Isn't the definition of a ground loop if your resistance in ground is different between different components? My grounds have 0.3 resistance at most between them.
The only think I found weird, sometimes speaker ground would show 0, and other speaker ground would show 2 omhs. I attached pictures with measurements.

I guess I'm gonna order a new alternator for the time being, while I continue troubleshooting


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## Bmwe39528i (9 mo ago)




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## doeboy (May 2, 2012)

Given all the time you have spent I just assume you have literally disconnected everything and just done a 1 by 1. Connect each component one at a time and test etc. Ground everything to the battery... eliminate headunit entirely with an iphone or android rca wire for direct input into amplifier... test each speaker one by one... etc. etc.


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## Bmwe39528i (9 mo ago)

I think my capacitor shorting out and wires melting was a blessing in disguise.
That night I redid the melted wiring and then I posted that I could not hear the whine. The next day the whine was back - don't know why or how! But yesterday I was testing and it was gone. Maybe it had something to do with the ground wiring.
I ordered a brand new oem bosch alternator just in case, cuz I really want to get this over with.
But now there seems to be no whine. There's still some low frequency noise coming from the tweeters, but it's very mild.
Funny thing, I tried to install those rca ground loop insulators to see if they'd help with the noise I have right now, and if I install one or two of them, they create so much whine and interference. When i disconnect those rca loop insulators, sound is nice and clear.
I went around all speakers and tweeters and put my ear next to them. I have some noise coming out of tweeters, it's like hissing/crackling/interference noise, but very faint.
But my rear right speaker and tweeters are making a really bad crackling noise.
I'll take the door apart and double check the connections, if speakers, tweeter and crossovers are properly connected.
I'll see if the whine comes back or if it's gone.
It's kinda weird that it's on and off.
I tried removing the NewMar alternator filter when there was no whine, and the whine didn't come back.
It's kinda embarrassing but maybe it was a bad ground after all? I'll keep testing and report back.


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## doeboy (May 2, 2012)

Sounds good. I think most of us on the forum just want you to get to where you need to be. A lot of us have encountered ground loops and it can be a real challenge dealing with them sometimes. Nobody envy's the trouble you have had to go through with this and I hope this is the end of the whine.


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## Bmwe39528i (9 mo ago)

Haha it just doesn't stop.

So everything was working fine, except the rear right speakers was sounding like this.





So I took the door apart to double check that everything was wired properly.
Then I tried powering different speakers from the same output on the amplifier. Sure enough, this horrible crackling, or I'm not sure how you'd call it, moved to a different speaker.
So I was pretty certain the amp output was bad...the pioneer one.
But now that it looks like I've solved the whine problem, I thought I'll try that infinity amplifier that I initially had, REF-704A.

Connected this app, and the rear right speaker was sounding fine.
So to me it confirmed that the pioneer amp was bad, or had bad output on channel B.

The only problem now, THE WHINE CAME BACK...With this infinity amp REF-704A

Geez looks like both amps are cooked and I need to order a third amp now


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## Fanatech (7 mo ago)

As someone with a similar install in a 2001 e38 740 with the same audio whine issues I'm following along. This is the thread that made me sign up for an acct here. Have tried many of the things you have done here to reduce whine with very limited success. Going to try an old high quality alpine head unit this week to see if it makes any meaningful difference. Although as you can imagine not too confident.


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## Bmwe39528i (9 mo ago)

Welcome aboard mate! E38 is one of my favorites I'd buy one if I had place to park it. Already got E39 and E53...My stock sound system on E39 1998 with a Chinese headunit sounds better than $2k sound system from 2020 lol 
Give alpine a try and see what happens.
I'm waiting for a new alternator and in the meantime I definitely need to try another amp.

Anyone has any suggestions?
Here's a few that I'm considering to try. Main factor is shipping on these is very speedy, so I can test it right away, instead of waiting weeks for shipping, which slows down the process a lot...

Alpine S-A55V 5 Channel Digital Amplifier

BOSS Audio Systems PF1800 Phantom 1800 Watt, 4 Channel, 2/4 Ohm Stable Class A/B, Full Range, Bridgeable, MOSFET Car Amplifier with Remote Subwoofer Control

BOSS AUDIO R2504 Riot 1000-Watt Full Range, Class A/B 2-8 Ohm Stable 4 Channel Amplifier with Remote Subwoofer Level Control

Amps that I've tried so far:

Infinity REF-704A
Pioneer GM-DX874


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## Fanatech (7 mo ago)

Hey there, still haven't received the harness for the alpine so install / test will be later this week. After going through this thread I found a post I now cannot find in the bowels of some euro 5 series forum. A member there described all of our issues and the only thing that resolved it was moving the cross over mounting location. My cross overs are in the rear drivers side cubby in the trunk where there is definitely EM interference possible. Before going down the rabbit hole of additional gear I would try moving those around and see what affect it has.

Going to try moving those in my 7 if this alpine head unit does not have the desired affect.

Another thought would be to try another ground location. Its hard to tell from your pics but when i installed a sub in my E39 I removed one of the bumper bar nuts sanded behind and used that for a ground. No ground loop in that car but that just uses an LC2i to an amp and sub very basic.

Will update.



Bmwe39528i said:


> Welcome aboard mate! E38 is one of my favorites I'd buy one if I had place to park it. Already got E39 and E53...My stock sound system on E39 1998 with a Chinese headunit sounds better than $2k sound system from 2020 lol
> Give alpine a try and see what happens.
> I'm waiting for a new alternator and in the meantime I definitely need to try another amp.
> 
> ...


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## ckirocz28 (Nov 29, 2017)

Bmwe39528i said:


> Haha it just doesn't stop.
> 
> So everything was working fine, except the rear right speakers was sounding like this.
> 
> ...


Please, please, tell me you're not running factory wiring to the speakers! If you're not, bypass/yank that problem speaker wire and see if it's shorted somewhere.

Sent from my SM-G935U using Tapatalk


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## Bmwe39528i (9 mo ago)

Haha of course I'm not running stock wires.
My system is 100% aftermarket. I don't have a single components, including wiring, that's still from my old system.

Headunit is powered by original wiring in the car lol. Then 6 rcas go to the trunk. 2 for sub amp, 4 for speaker amp. Then from the amp I got newly installed wires running to each crossover box in the door, which then powers both speakers and tweeters. Both amps powered directly from the battery and grounded in the trunk. For Headunit ground, I ran an extra wire directly from battery negative post.

The way I know the amp is bad and not the speaker, is that I tried powering this speaker from different channels of the amp, and it sounded fine. I also tried powering the 3 remaining speakers from this channel, and each speaker would have this problem.
Then I also swapped back to Infinity ref 704 amp, and that noise also disappeared. 
However infinity amp has this whine that is the source of this thread. On pioneer, I was somehow able to get rid of this whine.

Well I ordered a third amp and a brand new alternator, so will see how that goes


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## Bmwe39528i (9 mo ago)

I just want to post these pictures so the question of bad ground is dealt with once and for all. I used 0 gauge 40 inch wire to run from main ground point to disconnect switch. Then 40 inches 4 gauge back from the switch to battery ground. 
The ground for the amp comes from the same place where the battery is grounded on the main ground in the trunk. Then this ground splits in 2 to provide ground to both amps.
I used a professional crimping tool for terminals, you couldn't rip the terminals off the wires if you tried...all terminals and connection points sanded with sandpaper until shiny.


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## Bmwe39528i (9 mo ago)




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## ItsonlyaHONDA (Sep 9, 2021)

What is the purpose if the ground switch.


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## Bmwe39528i (9 mo ago)

The purpose of the ground switch is to be able to cut off power to the vehicle for various reasons. Once everything is installed in the trunk, the battery is highly unaccessible.
There's even a compressor bolted overtop. So if the car needd to sit for a week or two, I don't need to disconnect the battery, I just turn the switch.


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## ItsonlyaHONDA (Sep 9, 2021)

Bmwe39528i said:


> View attachment 338509
> 
> View attachment 338508
> 
> ...


Ahhh I see


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## lisuku (7 mo ago)

Bmwe39528i said:


> As to not waste your time with details I'll jump into the issue and what I tried so far.
> 
> Whining gets was worse when revving the engine. I understand it's called alternator whine.
> 
> ...


I had this problem and the problem was that 1 tweet was on 0db on the crossover and the other on +3 db, also any kind of noise was totally removed after installing dsp


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## Bmwe39528i (9 mo ago)

I think I uploaded too many pictures, they didn't all load. Should've been 10 pictures per post.
Anyways, battery fully charged, 13.2v. Battery maintainer indicated full charge as well.
Battery less than a year new, haven't driven the car more than 50 km since.
Putting in brand new bosch alternator from rock auto.


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## Bmwe39528i (9 mo ago)

lisuku said:


> I had this problem and the problem was that 1 tweet was on 0db on the crossover and the other on +3 db, also any kind of noise was totally removed after installing dsp


Now this is interesting!
My 4 crossovers also have this 3db button!
I broke one of these buttons on one of the crossovers! My friend told me not to worry about it! So I don't know if the button was pressed on unpressed when it broke!
What DSP did you get?
I'm wondering if the problem is cause by mismatch of those buttons on different crossovers. I.e. if some are set to +3 and some are set to 0. Or just the fact of having them pressed for +3db will make noise?


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## lisuku (7 mo ago)

Bmwe39528i said:


> Now this is interesting!
> My 4 crossovers also have this 3db button!
> I broke one of these buttons on one of the crossovers! My friend told me not to worry about it! So I don't know if the button was pressed on unpressed when it broke!
> What DSP did you get?
> I'm wondering if the problem is cause by mismatch of those buttons on different crossovers. I.e. if some are set to +3 and some are set to 0. Or just the fact of having them pressed for +3db will make noise?


definatelly is the crossover button, as I said problem, at the shop they suspected all kind of stuff till I fixed it myself in 3 seconds

my dsp is audison bit ten, 250€ pretty cheap, plan to upgrade tu audison bit 8.9


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## lisuku (7 mo ago)

lisuku said:


> definatelly is the crossover button, as I said problem, at the shop they suspected all kind of stuff till I fixed it myself in 3 seconds
> 
> my dsp is audison bit ten, 250€ pretty cheap, plan to upgrade tu audison bit 8.9
> 
> Also, if your front tweet (sorry didn't read the thread) is with the broken db swich, try swiching the other one on +3 if now is on 0 or on 0 if now is on +3 and that way you don't have mismach, and also check back tweeters if they are on the same db , I don't think it matters if is 0 or +3 but I would recomand 0 for lower noise as most of white noise usually come from tweeters and putting them on 0 eliminate lots of noise (I speak from personal problems not as a tehnician in any way)


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## Bmwe39528i (9 mo ago)

Thanks for your suggestion.
I will take the doors apart and play with dB switches on all crossovers and see if anything helps.


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## Bmwe39528i (9 mo ago)

Changed the alternator, installed new amp.
About to test it all.
But first before I connect the audio system, I want to test AC current with the new amp, to see if it even changed.
Cleaned up my install a bit. Not as messy but far from perfect. Once I get it working I'll make it neat
























Should I adjust anything here before turning on the system?


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## ItsonlyaHONDA (Sep 9, 2021)

I'd advise you not to mount your amps to the subwoofer especially "budget" amps. The vibration will shake the internals loose and you'll be returning back to Amazon in no time.


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## Bmwe39528i (9 mo ago)

Thanks I took it off the sub.

I don't think anything was wrong with the alternator.
Old alternator was showing 0.227 before the filter and 0.116 after the filter.
On battery terminal it was 0.017 A/C

New alternator is showing 0.187 before the filter, 0.092 after the filter, and 0.015 at the battery. These jump a bit, highest on battery was showing 0.024

At ignition wires maybe it's a bit high, 0.055 AC. I can install a small filter, as this is where the headunit gets power. I remember I installed a filter before, and it dropped to 0.
I guess time to test the amp


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## Bmwe39528i (9 mo ago)

New alternator (with newmar filter), New amp, New wiring....THE WHINE IS LOUDER THAN BEFORE.
I guess it's not amp at this point....
Bad crossover?


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## ItsonlyaHONDA (Sep 9, 2021)

You try grounding your battery wire without that switch.


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## ItsonlyaHONDA (Sep 9, 2021)

Does your car have an ANC


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## ItsonlyaHONDA (Sep 9, 2021)

ItsonlyaHONDA said:


> Does your car have an ANC


NVM you said everything is aftermarket.


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## Bmwe39528i (9 mo ago)

I disconnected the remote wire from sub amp to take it out of equation.
I tried powering different speakers. Just front two speakers, or just rear speakers.
Or just powering 1 speaker, front or rear.
No matter what, when key is "ON", I hear some high static noise, like buzz, or like noise from high voltage electrical lines. Coming from the tweeter. Then if I start the car, I can hear the whine.
Ground wire for the headunit is grounded directly where the amp and battery are grounded. I also tried using positive wire directly from the battery positive terminal to power the headunit.

I don’t have any ideas what's causing this. Maybe something is set wrong in amp settings?


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## Bmwe39528i (9 mo ago)

Tech worked on it for 12 hours straight and we couldn't fix the issue. 
All we figured, has something to do with headlight switch. Whine gets worse when turning the headlight knob.
Back to square 1 for now


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## yobbo7 (9 mo ago)

Did you try the transformers? It’s super likely to be a grounding issue somewhere. I highly doubt it’s your headlight switch.


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## JohnnyOhh (Feb 19, 2015)

what's going to be square 1? take it all out and re-do it?


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## LBaudio (Jan 9, 2009)

Read that Alpine book Ive sent you,...it will clear many questions you might have
Sort that cable mess you got, sort out all power wiring and grounds from ONLY one spot, recheck gains and lower them if needed, set apart signal from the power wiringrelocate amp if it is installed near fuel pump or cars computer,...... If you have a bad feeling about some component of the system, change it for test purpose with something else,...basically start over again with troubleshuting and be systemathic at doing that,...each time change only one thing and make test, and another and so on...


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## Bmwe39528i (9 mo ago)

yobbo7 said:


> Did you try the transformers? It’s super likely to be a grounding issue somewhere. I highly doubt it’s your headlight switch.


Still waiting for them. Says they should arrive by July 5.
Head light switch and adaptive headlights 100% have something to do with it.
You turn headlights on, static/whine gets x5 worse...


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## Bmwe39528i (9 mo ago)

JohnnyOhh said:


> what's going to be square 1? take it all out and re-do it?


Just in my head lol. I thought I had an idea what's wrong and how to fix it. Now I'm at a total loss.


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## Bmwe39528i (9 mo ago)

LBaudio said:


> Read that Alpine book Ive sent you,...it will clear many questions you might have
> Sort that cable mess you got, sort out all power wiring and grounds from ONLY one spot, recheck gains and lower them if needed, set apart signal from the power wiringrelocate amp if it is installed near fuel pump or cars computer,...... If you have a bad feeling about some component of the system, change it for test purpose with something else,...basically start over again with troubleshuting and be systemathic at doing that,...each time change only one thing and make test, and another and so on...


Yes my friend, now is the time to start reading and learning. I really wanted to get it fixed, but nothing is working. I'll take a step back now and download the 2Gb of your documents and start reading.
I really just wanted to get the damn audio working without getting a PhD in audio and electronics, but looks like I'll have to become on expert on this stuff before I can fix it.
I did fix the wiring mess, it's pretty clean now.
Ground and power for the amp and headunit come from the same location in the trunk.
Car computer is under the hood. Fuel pumps are under rear seat. Amp is in the trunk. Headunit is in the front.
The tech brought his own amp and speaker. Same issue with his components...
I swear the headlight switch has something to do with this stuff.
I remember when a few months ago I used my phone as a source of music by connecting 3.5mm jack to my phone and Y splitter to 2 rca ports on the amp, music was without interference. 
I don't know if 3.5mm to 4 rca adapters exist. At this point I'd be happy to just play music this way lol...


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## doeboy (May 2, 2012)

"I remember when a few months ago I used my phone as a source of music by connecting 3.5mm jack to my phone and Y splitter to 2 rca ports on the amp, music was without interference. "

This really says a lot right here. In your first post you mention that you ruled out the headunit yet when you eliminate it from the stack there is no more whine? If you can play music from a phone via an adapter into the amplifier with no interference then all your problems are in the HU.

I know some people have actually grounded the rca's to the casing of the head unit via a wiring wound around the outer shell on the rear of the headunit. I know a lot of the adapters for headunits are plastic now so the casing isn't attaching via metal to the car chassis anymore due to that plastic. They do make ground loop filters just for the head unit itself but you mentioned an attempt at that. I take it you don't have any headunits just sitting around as your latest statement tells me that either the HU is defective or the grounding there is not good.


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## Bmwe39528i (9 mo ago)

doeboy said:


> "I remember when a few months ago I used my phone as a source of music by connecting 3.5mm jack to my phone and Y splitter to 2 rca ports on the amp, music was without interference. "
> 
> This really says a lot right here. In your first post you mention that you ruled out the headunit yet when you eliminate it from the stack there is no more whine? If you can play music from a phone via an adapter into the amplifier with no interference then all your problems are in the HU.
> 
> I know some people have actually grounded the rca's to the casing of the head unit via a wiring wound around the outer shell on the rear of the headunit. I know a lot of the adapters for headunits are plastic now so the casing isn't attaching via metal to the car chassis anymore due to that plastic. They do make ground loop filters just for the head unit itself but you mentioned an attempt at that. I take it you don't have any headunits just sitting around as your latest statement tells me that either the HU is defective or the grounding there is not good.


I wish it was that simple. I replaced the headunit already and I tried grounding all rca ports on headunit together and grounding to headunit itself.
Also resistance between headunit casing and rca ports is 0


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## yobbo7 (9 mo ago)

Bmwe39528i said:


> Still waiting for them. Says they should arrive by July 5.
> Head light switch and adaptive headlights 100% have something to do with it.
> You turn headlights on, static/whine gets x5 worse...


Yes, it’s still likely a ground issue. Think about this, electric circuits are literal circuits. If you insert resistance in series with the system’s connection to ground, it has the same effect as inserting it in series with the connection to a load (in this case, the headlights). While it’s possible the lights are an issue, a bad ground connection will develop a voltage across it when current flows through and also cause worse effects when this happens. Are you sure your engine / chassis ground bond is good and not to a piece of metal that’s barely connected to the rest of the chassis or something?


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## Fanatech (7 mo ago)

Bmwe39528i said:


> Tech worked on it for 12 hours straight and we couldn't fix the issue.
> All we figured, has something to do with headlight switch. Whine gets worse when turning the headlight knob.
> Back to square 1 for now


Try disconnecting your HID ballasts if equipped also if aftermarket that could be causing alot of em interference. They are awfully noisy for ones system. The headlight switch itself is more or less a dummy that feeds signals to the bus for the LCM. IIRC it is only signal wiring going to that switch not likely to cause the noise itself. Does the whine go from moderate to worse when you turn the headlights on in key pos 2? (engine not running)

My 7 also had ZERO noise when running the system off a laptop or phone with the described 3.5mm to rca adapters. This was whether the car was running or not basically any key position with radio on. The blend door motors in the 5/7 series are also "Noisy" when playing around with my system i found the noise to be worse with the headunit mounted in the dash vs sitting in the passenger seat of the car (only with engine running). Still have not installed my alpine HU for testing will update when i have that in.

In regards to grounding the headunit chassis or rca's, been down that road with zero meaningful difference in this car.


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## shdw03 (Dec 30, 2018)

Bmwe39528i said:


> I wish it was that simple. I replaced the headunit already and I tried grounding all rca ports on headunit together and grounding to headunit itself.
> Also resistance between headunit casing and rca ports is 0


I had a very similar situation in my 4runner. Are you running with Passive crossovers? Where are they mounted?  There may be some electrical interference with the caps and coils causing the noise.

Before I ran active, I had originally planned to put my passive crossovers in the doors, but then I had this great idea. Since I was going to run active in the future, why not run new wires to the doors and mount the passive crossovers in cabin, then the rewire job would be simple. Found a great spot behind the kick panels, there was some open space next to the BCM on the passenger side. Wired up to my old rockford prime amp an all was good.... or so I thought. Driving to work the next day, I heard alternator whine, but was only on one side, the passenger side. Checked all wiring. swapped rca cables, still only on right side. Disconnected system, and even with no power or signal going to the speakers it would still make an alternator whine, with nothing connected!! 

Turned out to be that there was just enough electrical interference from the BCM that it would cause the audio noise through the passive crossovers. tested it out. Pulled crossovers from the mounting point, no noise. Put it next to the BCM, whine. tucked them up into the dash. problem solved.


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## ItsonlyaHONDA (Sep 9, 2021)

Have u tried something like this yet


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## ItsonlyaHONDA (Sep 9, 2021)

Maybe it's where your running your RCAs since connecting straight to the amp with that y splitter and had no noise. Maybe it's just the RCAs them selves


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## ItsonlyaHONDA (Sep 9, 2021)

May bad I just read that you've tried it already.


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## Bmwe39528i (9 mo ago)

yobbo7 said:


> Yes, it’s still likely a ground issue. Think about this, electric circuits are literal circuits. If you insert resistance in series with the system’s connection to ground, it has the same effect as inserting it in series with the connection to a load (in this case, the headlights). While it’s possible the lights are an issue, a bad ground connection will develop a voltage across it when current flows through and also cause worse effects when this happens. Are you sure your engine / chassis ground bond is good and not to a piece of metal that’s barely connected to the rest of the chassis or something?


I don’t disagree that it could be a ground issue...I just don't know how to find it
All I'm saying is my amp ground in the trunk is solid. Battery ground is solid. All grounds have 0 resistance between them.
Picture attached is the ground wire for engine block/chassis. While it's not my picture, it's the same on my car. I removed the cables and cleaned all surfaces with wire brush / sandpaper. Obviously cleaned wire terminals and made sure resistance is 0 between two points.


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## Bmwe39528i (9 mo ago)

Fanatech said:


> Try disconnecting your HID ballasts if equipped also if aftermarket that could be causing alot of em interference. They are awfully noisy for ones system. The headlight switch itself is more or less a dummy that feeds signals to the bus for the LCM. IIRC it is only signal wiring going to that switch not likely to cause the noise itself. Does the whine go from moderate to worse when you turn the headlights on in key pos 2? (engine not running)
> 
> My 7 also had ZERO noise when running the system off a laptop or phone with the described 3.5mm to rca adapters. This was whether the car was running or not basically any key position with radio on. The blend door motors in the 5/7 series are also "Noisy" when playing around with my system i found the noise to be worse with the headunit mounted in the dash vs sitting in the passenger seat of the car (only with engine running). Still have not installed my alpine HU for testing will update when i have that in.
> 
> In regards to grounding the headunit chassis or rca's, been down that road with zero meaningful difference in this car.


I disconnected all lights connectors. Rear and front lights and fog lights. I removed fuse 106 and 107 under the dash and it's still making that sound. Maybe the HID ballasts need to be disconnected separately, I'll check and maybe just remove the headlights completely.
Yea, the whine goes from moderate to horrible with key in 2nd position, vehicle not running.
I'm waiting for an update from you whe you installed your alpine amp on your 7 series


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## Bmwe39528i (9 mo ago)

shdw03 said:


> I had a very similar situation in my 4runner. Are you running with Passive crossovers? Where are they mounted? There may be some electrical interference with the caps and coils causing the noise.
> 
> Before I ran active, I had originally planned to put my passive crossovers in the doors, but then I had this great idea. Since I was going to run active in the future, why not run new wires to the doors and mount the passive crossovers in cabin, then the rewire job would be simple. Found a great spot behind the kick panels, there was some open space next to the BCM on the passenger side. Wired up to my old rockford prime amp an all was good.... or so I thought. Driving to work the next day, I heard alternator whine, but was only on one side, the passenger side. Checked all wiring. swapped rca cables, still only on right side. Disconnected system, and even with no power or signal going to the speakers it would still make an alternator whine, with nothing connected!!
> 
> Turned out to be that there was just enough electrical interference from the BCM that it would cause the audio noise through the passive crossovers. tested it out. Pulled crossovers from the mounting point, no noise. Put it next to the BCM, whine. tucked them up into the dash. problem solved.


Embarrassed to say I don't know the difference between active/passive. They're part of the speakers/tweeters Infijity Reference 6530CX.
They're mounted at the bottom of the doors, so I wouldn't anticipate any interference there 🤷‍♂️


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## ItsonlyaHONDA (Sep 9, 2021)

They are passive. With a crossover. Active is all speakers mid/tweeter powered with separate channels on your amp.


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## Bmwe39528i (9 mo ago)

ItsonlyaHONDA said:


> May bad I just read that you've tried it already.


I think I'll just record a 4k video and post it on YouTube. I feel I'm wasting everyone's time posting here. It's hard to explain everything in writing and lots of stuff will become clear and easy to see with the video.
The only limitation is sound will probably not translate perfectly.


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## shdw03 (Dec 30, 2018)

Bmwe39528i said:


> Embarrassed to say I don't know the difference between active/passive. They're part of the speakers/tweeters Infijity Reference 6530CX.
> They're mounted at the bottom of the doors, so I wouldn't anticipate any interference there 🤷‍♂️


this is mounted in your doors? is there anything next to it that might cause interference? window motors, control boards, wiring?


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## yobbo7 (9 mo ago)

Bmwe39528i said:


> I don’t disagree that it could be a ground issue...I just don't know how to find it
> All I'm saying is my amp ground in the trunk is solid. Battery ground is solid. All grounds have 0 resistance between them.
> Picture attached is the ground wire for engine block/chassis. While it's not my picture, it's the same on my car. I removed the cables and cleaned all surfaces with wire brush / sandpaper. Obviously cleaned wire terminals and made sure resistance is 0 between two points.
> View attachment 338831


That looks fine, I really don’t know, would have to be there to troubleshoot.


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## Bmwe39528i (9 mo ago)

shdw03 said:


> this is mounted in your doors? is there anything next to it that might cause interference? window motors, control boards, wiring?
> 
> View attachment 338836


Yes, I just used stick-on thin foam on the bottom of these little boxes and spray-glued them to the bottom of the doors inside, where they're low enough that the window won't touch them when rolled down.

Of course the doors have window motors/regulators, but they're not on, so they shouldn't interfere...


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## seafish (Aug 1, 2012)

Sorry not going to read the entire thread....

Did you ever have the alternaotor checked for a bad diode resulting in AC ripple voltage ??

Did you ever swap to another amplifier to make sure it is not a failing component within the amp??

Did you ever replace the HU or swap the music source to make sure it isnt the HU??


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## doeboy (May 2, 2012)

seafish said:


> Sorry not going to read the entire thread....
> 
> Did you ever have the alternaotor checked for a bad diode resulting in AC ripple voltage ??
> 
> ...


#3 when he uses a phone to rca connector there is no noise at all.


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## yobbo7 (9 mo ago)

I’m not sure where the issue lies but I’m like 75% sure the transformers will fix it. Not sure if fully though, depends if it’s common-mode.


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## Bmwe39528i (9 mo ago)

*PROGRESS*



doeboy said:


> "I remember when a few months ago I used my phone as a source of music by connecting 3.5mm jack to my phone and Y splitter to 2 rca ports on the amp, music was without interference. "
> 
> This really says a lot right here. In your first post you mention that you ruled out the headunit yet when you eliminate it from the stack there is no more whine? If you can play music from a phone via an adapter into the amplifier with no interference then all your problems are in the HU.
> 
> I know some people have actually grounded the rca's to the casing of the head unit via a wiring wound around the outer shell on the rear of the headunit. I know a lot of the adapters for headunits are plastic now so the casing isn't attaching via metal to the car chassis anymore due to that plastic. They do make ground loop filters just for the head unit itself but you mentioned an attempt at that. I take it you don't have any headunits just sitting around as your latest statement tells me that either the HU is defective or the grounding there is not good.


I know I said I tried it, which I did. But I need to revisit this.
Basically when I started this thread, I knew nothing about audio. So I was just mindlessly trying what people suggested without understanding what I was doing.
After trying for so long and no success, I came back to the only thing that has worked before. 3.5mm Y rca adapters.
The reason I didn't put so much faith in it before, is because when I plugged 2 rcas from HU to amp, it played way better than if I plug all 4.
Another factor is that I had whine with rcas plugged just into the amp, and not connected to the head unit.
And the third factor was that it's a second headunit.

And that's why I wanted to try phone jack to 4 rca adapter, but I don't know if it's possible and if such adapters exist...

So today I tried using just the old 3.5mm to 2 rca adapter and had no whine. I mean at least something works, so I decided to really concentrate on this stage.

I found 3.5mm to 4 rca adapter on Amazon. It's some no name brand with no reviews, so no clue if it's any good, but at least something to try.

I then tried connecting just 2 rcas to headunit and amp. The music kinda played muffled and not full frequency. The whine was pretty bad as well. I already tried grounding rcas to HU body and didn't feel like that would work but for some reason I felt like trying it.
So I tried connecting rca ports on headubit to the body of the headunit.
The whine completely disappeared!
I attached the wire to HU and as soon as I barely touched any of the 6 rca ports of the headunit with the other end of the wire, the whine was gone. 

Now, unfortunately, this does not fix all my problems...
When I connected all 4 channels instead of 2, the whine kinda creeped back, although a lot less loud. 
I tried moving rca cables around and connecting them to different ports on the headunit one by one, two, three, four.
And it's kinda weird. Some speakers/tweeters sounded great, some muffled, some had a bit of static, some a bit of whine. So it's like out of 4 doors, each played differently.
This is kinda weird behavior and it really make me feel like the headunit is the problem. Or a major contributor.

So I ordered more rca cables just to rule them out one more time
Amazon Basics 2-Male to 2-Male RCA Audio Stereo Subwoofer Cable - 8 Feet Amazon Basics 2-Male to 2-Male RCA Audio Stereo Subwoofer Cable - 8 Feet : Amazon.ca: Electronics

These seem to be bulletproof cables!

Also ordered a brand new headunit
Alpine UTE-73BT Mech-less Digital Media Receiver with Bluetooth® Wireless Technology Alpine UTE-73BT Mech-less Digital Media Receiver with Bluetooth® Wireless Technology : Amazon.ca: Electronics

I feel like it's really weird that the more rcas I connect to the headunit, the worse it's playing, and doesn't play equal in all doors. 
With how much $ and time I've spent so far, I feel trying out another headunit would be worth a try!


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## Bmwe39528i (9 mo ago)

yobbo7 said:


> I’m not sure where the issue lies but I’m like 75% sure the transformers will fix it. Not sure if fully though, depends if it’s common-mode.


I'm afraid they won't do anything, because when I tried rca filters, they did nothing.


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## yobbo7 (9 mo ago)

Bmwe39528i said:


> I'm afraid they won't do anything, because when I tried rca filters, they did nothing.


A transformer is not a filter. Filters don’t do ****.


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## seafish (Aug 1, 2012)

Bmwe39528i said:


> And the third factor was that it's a second headunit.


Are you saying that you have TWO head units connected at the same time or that you are already using a different HU and the same whine problem persists??



Bmwe39528i said:


> I then tried connecting just 2 rcas to headunit and amp. The music kinda played muffled and not full frequency. The whine was pretty bad as well. I already tried grounding rcas to HU body and didn't feel like that would work but for some reason I felt like trying it.
> So I tried connecting rca ports on headubit to the body of the headunit.
> The whine completely disappeared!
> I attached the wire to HU and as soon as I barely touched any of the 6 rca ports of the headunit with the other end of the wire, the whine was gone.


it is very difficult to understand the specifics of what you are doing here!!!

Are you plugging in your phone speaker jack to the HU aux input?
Or are you plugging it into the amplifier inputs?
Or BOTH ??

THAT SAID ... if grounding the HU body eliminates the whine, then your HU is not installed and grounded properly.
Your problem might be THAT simple !!!

Go back and double check your HU install and grounding points...also be sure to ground the HU to the same poin that the amplifiers are grounded to



Bmwe39528i said:


> I feel like it's really weird that the more rcas I connect to the headunit, the worse it's playing, and doesn't play equal in all doors.


The more you split the Y cable from your phone source the less power goes to each RCA thus the sound from each speaker is more muffled and uneven.

ALSO, if you are simply plugging in the speaker phone jack into the either the HU or the amp and then moving it around, then the crossovers in the HU or the amps would definitely affect the sound quality coming out of each speaker.


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## Bmwe39528i (9 mo ago)

I'm sorry if my post was confusing.
I didn't connect both headunits at the same time.
I had Kenwood KDC-X302 as my first headunit while I had this whine problem.
It died, so I bought Kenwood KDC-X304 and have the same whine. I bought Kenwood KDC-X304 second hand. Maybe it was bad, that's why the person was selling it?

I was trying to say, when I used my phone as audio source, there's no whine.
Basically this adapter.
AmazonBasics 3.5mm to 2-Male RCA Adapter Audio Stereo Cable - 4 Feet AmazonBasics 3.5mm to 2-Male RCA Adapter Audio Stereo Cable - 4 Feet : Amazon.ca: Electronics


I'm not connecting my phone to AUX on the headunit. Just connecting my phone to amplifier via this adapter.

Grounding headunit body to headunit RCA ports (this is where rca cables running from amp are plugged) helps with the whine but doesn't totally eliminate it.

If I only use two channels I think the whine is gone. But if I use 4 channels, the whine is there. And I don't know why it's happening.
So if I have 2 rca cables running from the amp to HU, I'm able to get rid of the whine. If I plug another rca cable into the headunit, the whine starts creeping back.
This has been the issue from the beginning, that on two channels it's been ok, but not on four. So I'm wondering if headunit is the problem or if it's still related to grounding/power issues?

That's why the test where I connected my phone to amplifier and played music from my phone is inconclusive. Because I can only power 2 channels from my phone. I cannot power 4 channels so far.

Tomorrow I'm getting a new alpine headunit and also rca splitter for 4 channels, like I mentioned in a previous post.
So if I can use my phone as an audio source for all 4 channels of the amplifier, then it'd be interesting to see if there's any whine.
Then I can also test new rca cables and new headunit.


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## LBaudio (Jan 9, 2009)

So, the conclusion so far is that HEad unit obviously has some problem, probably with micro fuse. If you still have noise issues and everything else is correctly installed, then try to lower your gains since that might also be a problem and causing noise.
IF speakers are not equaly loud L/R or F/R, then check your head unit settings like balance and fader. 
If Alpine HU does have 4 stereo RCA outputs,connect them all to the amp.
Also, check how amp inputs are configured....

at least we have some progress


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## Bmwe39528i (9 mo ago)

Knowing how treacherous this system has been, I'm not drawing any conclusions yet
But today will reveal a lot.
I set my headunit to flat balance everywhere in settings and the set it to 75% of top loudness and then start turning gains up slowly from 0.
Both headunits have 6 rca preamps, as I need 4 for the speaker amp and 2 more for sunbwoofer amp.
Kenwood hu has 5v preouts and alpine hu has 2v preouts. I heard 5v is better, but I'm not sure it really mattets at my level. I set my up to 100mv-2v sensitivity on the amp. I read that's the right setting even if headunit preamp output is higher.
Bass boost is at its lowest.
Only question I wonder, if I need to set up high pass filters for my speakers/tweeters.

Channel 1 is for the front speakers and tweeters+crossover, channel 2 is for rear speakers and tweeters + crossovers

I included a picture of the rear of my amp

Sub and amp for sub are disconnected for now. Trying to figure out the speakers first.

Still waiting on those transformers, they're taking forever.


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## LBaudio (Jan 9, 2009)

I suggest to you that you weight tunning options on HU and AMP, and decide where you will make x-over settings (Head unit or amp) to avoid confusion set settings on only HU or only on AMP .

You can definitely set hi-pass for front system - let say arround 70-80Hz for starters. CH 1/2 front, ch 3/4 rear... Bass boost is only option on channels 3/4.


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## Bmwe39528i (9 mo ago)

With how often my headunit gets disconnected right now to work on things, I should stick with making settings only on the amp.
Right now my settings are set to FULL (attached picture was a screenshot from a product page).
How do you set frequency to 70-80 Hz when the dial has such a wide range, 50-500 Hz, with no indicators in between??

Bass boots is probably just useless on this amp for me. I figure it assumes you're running 2 channels for speakers, and 2 rear channels for sub, which could then get boosted. But since I have a separate amp for a sub, I won't have to worry about it.


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## Bmwe39528i (9 mo ago)

*Test #1* - phone to amp adapter- success

Used 3.5mm phone jack to drive all 4 rca cables going to the amp. No whine.
Maybe I should just use an extension for this cable and listen to music this way?! How good is Galaxy S21 phone compared to a headunit?

*Test #2* - rf chokes - fail
Used those clip on choke filters on power lines to amp, HU etc., did absolutely nothing.

*Test #3* - new headunit - fail
Powered up new headunit.
Whine is still there. Tested resistance between amp ground and HU ground - 0.
If headunit is on, resistance goes up to 50ohmn. Probably normal.

Now the main thing. I say main because this hasn't changed after changing amps and headunits.

If I connect 2 rcas between amp and HU, it seems to play fine, I can set the gain pretty high, no whine. There's some faint sound coming from the tweeters, like a bird flapping its wings, but it's pretty mild.
Now if I connect 3 or all 4 rcas, this is where I'm getting the whine again.
Only if I set gains to 0 on the amp, does the whine disappear with the car idling.
But if I put my ear next to the speakers/tweeters, I can hear it again!

I don't understand why there's no whine with 2 channels, but whine come back at 3 or 4 channels?

Also I'm not sure if it matters, my channel 1&2 seem to be giving sound on the left side speakers, front and back. While channels 3&4 drive the right front and left doors.
I thought channel 1&2 was for front doors, and channel 3&4 for rear doors. Does this make any difference?

*Last*
I ordered new rca cables, and the picture lead me to believe there would be 2 cables x 2 rcas. I only got one cable, which only runs 2 channels. I'm going to order another cable to exclude the possibility of bad rca cables or interference.


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## NW JLUR (Dec 3, 2018)

Bmwe39528i said:


> Also I'm not sure if it matters, my channel 1&2 seem to be giving sound on the left side speakers, front and back. While channels 3&4 drive the right front and left doors.
> I thought channel 1&2 was for front doors, and channel 3&4 for rear doors. Does this make any difference?


Sounds like you need to check your wiring. You can use a battery like a 9 volt to test speaker wires from the trunk. Disconnect all the wires from the amp and test. Did you say the noise went away when you tested with the head unit in the trunk? Where did you get power from? Did you draw power from the trunk or extend power wires from the dash? If it worked powering the head unit from the trunk maybe try running a power wire to the dash.


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## Bmwe39528i (9 mo ago)

Could you elaborate on how to test the speakers with a 9 volt battery? Like energizer?









When I previously tested in the trunk with no noise, I don't remember if I used 2 or 4 channels. I also used twisted pair rca cables running overtop of the carpet, and I discarded those cables, as they were old and cheap. I also learned that my system needs insulated rcas, not twisted pairs. I know for sure I previously grounded the headunit on the amplifier ground, and for power I used ignition switch wires. Right now I'm using a wire I ran off the battery's positive terminal. I also tried to power again with ignition wires, but that didn't help.
Tomorrow I'll have new rca cables on hands to test them. I feel maybe there's some interference for some reason.
I should also be getting those Jensen transformers this week, so will finally give them a go!


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## NW JLUR (Dec 3, 2018)

Yes like the one pictured. Disconnect all your speaker wires. Touch the positive wire to one terminal and tap the other wire to the negative post. The speaker it’s attached to will make a popping sound. Use that to verify all your wires are connected correctly. You can also test polarity if you can see the speaker moving.


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## Bmwe39528i (9 mo ago)

Alright so I got a second set of rca amazon basics cables. I was like, ok, I'm gonna connect these cables and the whine is gonna be there, so then I'll connect my old cables on one end, connect Jensen transformers in between, and connect amazon on the other end.
UNBELIEVABLY, the whine disappeared with only amazon cables!
I just disconnected old rca cables and connected Amazon cables running over the carpet of the vehicle.
Amazon Basics 2-Male to 2-Male RCA Audio Stereo Subwoofer Cable - 8 Feet Amazon Basics 2-Male to 2-Male RCA Audio Stereo Subwoofer Cable - 8 Feet : Amazon.ca: Electronics
BOOM!
Whine is gone. Plugged back old cables, whine came back. Plugged amazon cables, no whine. Turned gains on the amp to MAX, no whine. 
Holy moly, so much frustration, money and time and I'm 100% certain the issue is rca cables.
Now, I don't know if the issue is bad cables or interference. Now lots of people will rightfully think that I have mentioned that I tried another set of rca cables. And that's correct. The only problem, one set of rca cables I tried was twisted pair. I didn't fully know or understand this term, nor could I tell the difference by looking at them.
So that's why the previous test of substituting rca cables was invalid. I was using the wrong type of rca! I used rcas from this amp set
KnuKonceptz Bassik 0 Gauge Complete Amplifier Installation Amp Wiring Kit with RCA KnuKonceptz Bassik 0 Gauge Complete Amplifier Installation Amp Wiring Kit with RCA : Amazon.ca: Electronics
And they're twisted pair, no good!
The cables running under the carpet are Fospower 
FosPower (7.6m / 25ft) 2 RCA M/M Stereo Audio Cable [24K Gold Plated | Copper Core] 2RCA Male to 2RCA Male [Left/Right] Premium Sound Quality Plug FosPower (7.6m / 25ft) 2 RCA M/M Stereo Audio Cable [24K Gold Plated | Copper Core] 2RCA Male to 2RCA Male [Left/Right] Premium Sound Quality Plug : Amazon.ca: Electronics

Based on Amazon reviews, these cables seem fine, but who knows...

Just to avoid any further problems, I want to run new rca cables through the headliner!
I ordered longer cables, MonoPrice. Seems to be decent quality.
Monoprice 105348 15-Feet 22AWG Premium 2 RCA Plug to 2 RCA Plug Audio Cable, Black Monoprice 105348 15-Feet 22AWG Premium 2 RCA Plug to 2 RCA Plug Audio Cable, Black : Amazon.ca: Electronics

15 feet should work for my idea
I drew a red line with how I plan to run them.
I haven't heard anyone running rca cables under the headliner, but why not??


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## Bmwe39528i (9 mo ago)




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## ckirocz28 (Nov 29, 2017)

Bmwe39528i said:


> Alright so I got a second set of rca amazon basics cables. I was like, ok, I'm gonna connect these cables and the whine is gonna be there, so then I'll connect my old cables on one end, connect Jensen transformers in between, and connect amazon on the other end.
> UNBELIEVABLY, the whine disappeared with only amazon cables!
> I just disconnected old rca cables and connected Amazon cables running over the carpet of the vehicle.
> Amazon Basics 2-Male to 2-Male RCA Audio Stereo Subwoofer Cable - 8 Feet Amazon Basics 2-Male to 2-Male RCA Audio Stereo Subwoofer Cable - 8 Feet : Amazon.ca: Electronics
> ...


I'm glad you got it figured out! It was becoming increasingly clear that the only possible cause left was the rca's.

Sent from my SM-G935U using Tapatalk


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## ItsonlyaHONDA (Sep 9, 2021)

Bmwe39528i said:


>


I still suggest you don't mount your amps to your sub, again. I know from experience that eventually the amp will fail. But it's your world, do as you please. I'm glad you found your problem. When you pull the old RCAs out see if you may have ran it too close to the power wire or a fuel pump.


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## Bmwe39528i (9 mo ago)

It's temporary, I haven't even decided if I'm going to keep this amp or not. I will find a better place for it. It's just easier for now to keep things together and clean.









My rcas run in the center of the car, and power lines are on the left and right side, unless they're picking up interference where they pass by the center console or in cargo area fused power distribution center.
At this moment I'm just ecstatic this has finally been resolved and I can put the vehicle back together and enjoy the sound!


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## Dark Winter (9 mo ago)

I suspect that the new Amazon Basics cables you got are coax; and according to the product page at Monoprice the 105348 cables are coax as well. Coaxial cable provides the best shielding you can get.

This pretty much nails it - it's not alternator whine in the +12v power rail; it's interference being picked up by the other cables... possibly from the ignition system; or some switching power supply or PWM motor controller.


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## Bmwe39528i (9 mo ago)

Thanks for the explanation! I literally spent like $3000 and then fixed it with $30 cables. 
I will update the thread soon when I get everything rewired and tested out!


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## yobbo7 (9 mo ago)

Bmwe39528i said:


> Thanks for the explanation! I literally spent like $3000 and then fixed it with $30 cables.
> I will update the thread soon when I get everything rewired and tested out!


Be curious if the transformers are able to reject the noise with your old RCAs though if you’re able to test it. Glad you found the issue.


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## Bmwe39528i (9 mo ago)

Yes tested just for this purpose, transformers do reject the noise. Also, even with my old headunit, which has an internal ground problem, they do reject the noise, I'd say between 95 and 99%.
I tried the old headunit, without grounding the rca ports to the body of the HU, the noise is so bad...it's louder than music. With transformers, the noise is pretty much gone.
Now I need to list these transformers on ebay lol cuz the seller doesn't accept returns.


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## yobbo7 (9 mo ago)

Bmwe39528i said:


> Yes tested just for this purpose, transformers do reject the noise. Also, even with my old headunit, which has an internal ground problem, they do reject the noise, I'd say between 95 and 99%.
> I tried the old headunit, without grounding the rca ports to the body of the HU, the noise is so bad...it's louder than music. With transformers, the noise is pretty much gone.
> Now I need to list these transformers on ebay lol cuz the seller doesn't accept returns.


Sorry lol, but at least they do work. I thought they would.


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## Bmwe39528i (9 mo ago)

Man I'm glad they work and I'm just glad everything works! I don't regret buying them, if I didn't find the problem, they would've ender my misery 
My sounds is so good now, even if I'm at full volume and pause the music, there's no static, no buzz, no hum, no nothing, even if put my ear right next to the speakers or tweeters!


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## JohnnyOhh (Feb 19, 2015)

what type / brand /model of transformers did you end up buying and having success with? - glad you got it sorted out.


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## Bmwe39528i (9 mo ago)

Jensen Iso Max CI-2RR
Really expensive but fantastic units. 
Maybe I'll keep them just in case any issues ever arise, in this vehicle or another.


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## Bmwe39528i (9 mo ago)

Well you guys all are gonna think I'm crazy, but the whine is back.
I thought myself I was crazy.
Went for a drive, whine back 100%

Geez ok, what now???
Tried those amazon rca cables again, whine is there. Hmmmm...
Tried phone jack to 4 rca cable splitter, whine is there...Wow that's new, it wasn't there before when I was troubleshooting this problem. Something new is happening.

My gf was with me sitting in the back, and I asked her to listen for the noise.
Well what's crazy, she kept saying it was the amp.
I was like, amp is not a speaker, it doesn't produce any sound and noise can't come from there. So even with car running and music on pause and low, without revving it up, she said she could hear the noise, while I heard nothing. I'm like, ok, should I order amp #5? I mean yeah, this amp is cheap, but that'd be quite a coincidence! 4 amps and all have the same problem? Highly unlikely!
What gives?? I disconnected the head unit, rca cables from the amp, noise still there.
I disconnected the remote wire, so the amp doesn't turn on. Noise still there!
Now I'm really puzzled, where is this freaking noise coming from, both amps are off, headunit is off, rca cables disconnected so they can't pick up any distortions, what's making noise???

So I started sticking my head everywhere around the amp.
Well with my gf's help we located the problem, and there's really no doubt.
I put my ear to these splitters, and the noise is coming from there loud and clear. But really clear if I put my ear next to it.










Wow, I didn't know wires can produce whine. I never heard or rear this on any forums.
So maybe I fixed the rca cables, and the moved sub around from trunk to backseat and back, and some cable got loose or something.

Both boxes are making whine.

One box is for the ground. It's grounded at factory ground location with 0 gauge wire, goes to the box on the picture, and then splits into two 4 gauge wires that go to each amp.

The other box is also 0 gauge wire, coming directly from battery positive. It goes into that box and splits into two 4 gauge wires that power both amps.

So I'll check the connections and maybe just crimp the 2x4 gauge and 0 gauge wires together with hydraulic crimper, and avoid these boxes. I'm not sure what's causing the WIRE WHINE. Bad connection or something else.


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## ItsonlyaHONDA (Sep 9, 2021)

Maybe there, where the ground and 12v are crossing and touching each other. 🤷🏽 what kind of wire is that OFC?


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## Bmwe39528i (9 mo ago)

Wire type is CCA
This kit.
Used this 0 gauge for positive and negative to the amp.

KnuKonceptz Bassik 0 Gauge Complete Amplifier Installation Amp Wiring Kit with RCA KnuKonceptz Bassik 0 Gauge Complete Amplifier Installation Amp Wiring Kit with RCA : Amazon.ca: Electronics

Should I get OFC instead?
Never heard of either OFC or CCA

No what the wires could be touching, but I'll recheck it tomorrow. Can't be sure of anything at this rate.


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## ItsonlyaHONDA (Sep 9, 2021)

Yea CCA is no good. I don't know if it would cause a wine but you never know OFC oxygen free copper, CCA copper clad aluminum. Read that ⬇ 









Cheap 4 ga wireing


https://www.amazon.com/gp/product/B01MXRVIPD/ref=ppx_yo_dt_b_asin_title_o04_s00?ie=UTF8&psc=1 litterly made a account to share this deal, yw :p




www.diymobileaudio.com


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## Bmwe39528i (9 mo ago)

Sounds good ordered OFC instead!

KnuKonceptz Kolossus Flex 0 Gauge OFC Power Amp Wiring Kit KnuKonceptz Kolossus Flex 0 Gauge OFC Power Amp Wiring Kit : Amazon.ca: Electronics

Thanks for teaching the difference between CCA and OFC.
From a brief search inline, it looks like CCA is garbage. 

_Not only that, but I've seen some CCA wire that actually broke away and separated from the battery and amplifier terminals because it literally turned into powdered dust after just 3 years in the car.

In addition, aluminum will fracture and break much sooner than copper when bending it (especially bending it in tight radiuses and repeated bending) and under vibrational loads such as the engine compartment of a vehicle._


This is from the thread you linked. I felt that was my experience when cutting it. The damn cable felt like it was falling apart and turning into powder. This can't be good...


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## JohnnyOhh (Feb 19, 2015)

did adding those clip-on ferrite beads/rings around the power and ground wires help at all? i see you have many in there. what frequency did you use? they are designed to work for certain frequencies, fyi.


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## Bmwe39528i (9 mo ago)

Yeah lol I got a bag of them and added them everywhere. Unfortunately they've done absolutely nothing. 0 difference at all.
This is a head scratcher. I've heard DC voltage doesn't produce sound. So the fact that I hear the whine from junction boxes means it has ripple maybe. I'll need to get an oscilloscope probably to measure for sure.
Or maybe just use those Jensen transformers.
I'll recheck if the ground is getting a short somehow. This whine with HU and rca cables disconnected kinda makes no sense now.


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## ckirocz28 (Nov 29, 2017)

Bmwe39528i said:


> Yeah lol I got a bag of them and added them everywhere. Unfortunately they've done absolutely nothing. 0 difference at all.
> This is a head scratcher. I've heard DC voltage doesn't produce sound. So the fact that I hear the whine from junction boxes means it has ripple maybe. I'll need to get an oscilloscope probably to measure for sure.
> Or maybe just use those Jensen transformers.
> I'll recheck if the ground is getting a short somehow. This whine with HU and rca cables disconnected kinda makes no sense now.


You just need to burn that car! 
I know you said the amps aren't on (remote turn-on disconnected), but are you sure? Sometimes the big toroidal transformers inside can whine.


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## Bmwe39528i (9 mo ago)

I wish I could just burn it and start new, if I haven't invested so much lol!

I crimped 0 gauge and 4 gauge wires together, instead of using a junction box.
There was no whine where I crimped the wires, but the whine was still coming from somewhere. So I kept looking around,

And.

So these ferrite chokes, especially around power and ground wires by the amp, were actually also making whiny noise!
I don’t know if the chokes themselves are making noise or if they're simply picking up noise and transmitting it. I really don't understand what's going on, but at least I traced them to the wires...

So I'm gonna get my girlfriend to listen and see if we can find where the whine is coming from now.

But let's say the whine doesn't go away until I actually disconnect 4 gauge power and ground wires from the amp.
What do I do next lol?


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## JohnnyOhh (Feb 19, 2015)

so after you had the problem solved ....then later you added the ferrite chokes -> and you heard noise?


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## Bmwe39528i (9 mo ago)

No the problem was solved after I put the chokes on, by simply swapping the rca cables. Literally it was the one and only variable...
So now I removed the splitter boxes, removed all the chokes, and had my gf listen for noise.

















She's saying noise is gone, so I'll take the vehicle for a drive tomorrow to double check.
I should get the OFC wires tomorrow so I can replace the vehicle ground wire and ground and power wires for the amp with good quality OFC wire instead of CCA.


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## ckirocz28 (Nov 29, 2017)

Bmwe39528i said:


> I wish I could just burn it and start new, if I haven't invested so much lol!
> 
> I crimped 0 gauge and 4 gauge wires together, instead of using a junction box.
> There was no whine where I crimped the wires, but the whine was still coming from somewhere. So I kept looking around,
> ...


The chokes can't MAKE noise, they can only REACT to noise. Does that car have a CAN bus? That's the only thing I can think of that might be so pervasive in a car, some CAN bus signal grounded out somewhere or just running through everything everywhere.


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## Dark Winter (9 mo ago)

Something very weird is going on here...

Consider for a moment: your household wiring is 60hz AC; and carries both relatively high voltage (120 or 240 volts) and high power (an electric dryer or oven plug can supply up to 12,000 watts)... and is totally silent. Even with something electrically nasty connected like a high-power PWM motor controller without proper line filtering; the wiring is still acoustically silent.

So, even if the 12V DC power connected to that wiring had a huge amount of AC noise on it - both voltage and current - it shouldn't be physically capable of producing audible sound.

Devices that _do_ produce audible sound from voltage or current always involve either a substantial magnetic field (speakers for example have comparably strong electromagnet coils and permanent magnets to magnetically react against), very large voltages (for example, in electrostatic speakers - but this is in the kilovolt range, well beyond what would fry all the electronics on your car), or very large surface area (electrolytic capacitors, for example, have a very long roll of thin metal film inside their can, and that adds up to a _lot_ of area between the two plates of the capacitor - something a simple wire just doesn't have).


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## Bmwe39528i (9 mo ago)

ckirocz28 said:


> The chokes can't MAKE noise, they can only REACT to noise. Does that car have a CAN bus? That's the only thing I can think of that might be so pervasive in a car, some CAN bus signal grounded out somewhere or just running through everything everywhere.


Well, whatever it was, the noise was coming right from those chokes. Removed the choke, the noise disappeared from that spot. I don't know what's going on. Beyond anything I understand.
But before that, the noise was coming from junction boxes for 0 gauge to 4 gauge wires! How's that possible? That box has nothing to make noise it's a metal box that connects wires together with a screw. But the whine was coming from there, loud and clear!

If a signal was grounded improperly, shouldn't I get voltage measurement at ground points?
As to canbus, I don't think there's much in my X5 2002.


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## Bmwe39528i (9 mo ago)

Dark Winter said:


> Something very weird is going on here...
> 
> Consider for a moment: your household wiring is 60hz AC; and carries both relatively high voltage (120 or 240 volts) and high power (an electric dryer or oven plug can supply up to 12,000 watts)... and is totally silent. Even with something electrically nasty connected like a high-power PWM motor controller without proper line filtering; the wiring is still acoustically silent.
> 
> ...


Well, all I can say is that there's bo AC voltage. #1 I installed alternator filter, #2 I measured AC voltage and it's super low.
That's why I don't think AC is causing it
If AC was the issue, then I'd be able to measure it, right?

So the only other thing from your explanation to produce noise would be magnets. Because I don't have kilovolts in my vehicle 

So now that I've looked at the pictures again, right where those "T" junction boxes are, I also had those chokes right next to the boxes.
Maybe it was those chokes producing the whine, since they are made of magnets!
I don't remember if I checked if T boxes made noise without the chokes or not.

I'll do some more testing. I'll add the T boxes without the chokes and see what happens, and then add chokes.
Either way have to do some rewiring to use OFC wires instead of CCA


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## Bmwe39528i (9 mo ago)

Installed OFC for ground and power wires going to the amp, I think the whine is gone.
Also, I used 0 gauge wires from battery and ground to the amp. I used 4 gauge to 0 gauge reducer connector to use 0 gauge wire.

Installed an extra fusebox and fused both amps at 40 amps as per manual from RD400 JL.
The new amp I bought for my speakers, RD400 JL, has a clip light to set the gains.

So after setting everything up, I don't hear the whine anymore. I think those magnets were making things worse. Power wire was probably creating a small magnetic field, and these magnets were making it worse. Who knows!
Now I do get a slight static from the speakers/tweeters when the music is paused. My gains are dialed in properly.

The static at some point got extremely bad as I was testing, and I saw that one rca cable fell out of the headunit. I put it back, and as I was wiggling the rca cables in the headunit, the static would change. 
Now I'm thinking it's the rca cables causing static due to not being well grounded inside or smth. I bent the rca connectors to make them tighter, so they're super tight on the headunit plugs, but the static is still there.
I dont know how to exactly describe it, it's like a static mixed with some hissing/sheeshing and is rhythmic. It sounds like a small bird flapping its wings.
I'm thinking Monoprice rcas are not high quality cables and I heard people complain in reviews about loose connections.

I ordered Amazon basics rca cables again.
I also ordered BJC LC-1 Stereo Audio Cables.
There's so much mumbo jumbo on the internet with regards to interconnects, but I think BJC are considered no shill high quality cables. They set me back $250 but I hope a pair or BJC and Amazon rcas will allow me to figure out if the static is caused by rca cables or something else.


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## ItsonlyaHONDA (Sep 9, 2021)

I have both stinger, and knukonceptz RCAs in my build. not expensive, not cheap, no noise. But I'm also not running RCAs across the car so 🤷🏽‍♂️


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## seafish (Aug 1, 2012)

If the RCA cable simply fell off during your install, then likely the barrel is not crimped tightly enough to make a solid connection...static from wiggling the RCA is also a sign of a poor connection.

Prolly time to lightly crimp the female barrel connectors a LITTLE tighter (you do want to be able to pull them off without breaking anything) and then reconnect them to see if static is gone.


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## Bmwe39528i (9 mo ago)

That's exactly what I tried. Made them tight by crimping them slightly.
But there's still a bit of static in the speakers and tweeters. So I'm going to try other cables. I don't want this static to be there, I don't think it should be there.
Cables are a bit tricky. There's digital and analog audio cables.
I'm not sure what the deal is. I know digital audio needs coaxial rca cables and analog doesn't need them.
I don't know if my car audio is digital or analog.
I know coaxial are better at radio interference rejection, and analog are better at electromagnetic interference.
Since I don't have radio in my car, analog should be better.

I know these are high quality coaxial cables 
BJC Coaxial Digital Audio Cable, 3 foot, Black https://a.co/d/2ARv9M6

And these are analog. So I guess I'll try both. 
BJC LC-1 Stereo Audio Cables, 15 Foot https://a.co/d/c5Zn3GA

At least with blue jeans, I know it's high quality cables. Enough high quality not to have bad grounds...


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## Bmwe39528i (9 mo ago)

Tried amazon coaxial interconnects, and have the same problem. No change.
Here's what it sounds like:




__





Vocaroo | Online voice recorder


Vocaroo is a quick and easy way to share voice messages over the interwebs.




voca.ro




If I disconnect the cables from the amp, the noise disappears.

I tried using the 3.5mm adapter to 2 rca again, and again 95% of that remaining static disappeared. 
I used this connector, by the brand of Monoprice





__





UGREEN 3.5mm to 2 RCA Male to Male Aux Audio Cable Cord 3.5mm Stereo Jack to 2RCA Phono Plugs Connector for Speakers, iPod, MP3 Player, Smartphone, Tablet, Laptop and More, 3ft : Amazon.ca: Electronics


UGREEN 3.5mm to 2 RCA Male to Male Aux Audio Cable Cord 3.5mm Stereo Jack to 2RCA Phono Plugs Connector for Speakers, iPod, MP3 Player, Smartphone, Tablet, Laptop and More, 3ft : Amazon.ca: Electronics



a.co





And when I connect the rca cable just to the amp side, not even the headunit, I can hear that noise.

So like, this is really weird.
Just the simple fact of connecting rca cables to the amp, and I only used front channels, introduces this static.

So really, I connect even one single rca cable to the amp, and I'm getting static.
I insert a different cable into the amp, the Y adapter, and there's no noise. Regardless whether I connect the other end to my phone or leave it disconnected.

This means I gotta keep trying different rca cables?
Any thoughts??


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## Bmwe39528i (9 mo ago)

So I can't even use the Jensen transformers for this problem, because they go between the headunit and the amp. But in this case, even with headunit disconnected completely, I can hear the noise.
Actually if step on gas pedal, even if I touch it ever so slightly, I can hear change in the noise. I feel this is still a remnant of the alternator whine...

So this is the testing set up.

Amp powered from the battery. RD400 JL
Headunit disconnected completely.
Just 2 wires connected for left front speaker.
Only one amp connected in the system.
But as soon as I connect rca into the amp, I get that faint static?


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## Bmwe39528i (9 mo ago)

At this point, it boils down to this:

- I connect one end of rca cable (monoprice or amazon basic) to amp output, I get static in speaker/tweeter.
(Even if I pull this rca cable outside of my trunk, so that it doesn't pick up any interference from even being in the vehicle.)


- I connect/plug one end of the Y adapter (2 rca to 3.5mm aux jack) and there's no static in the speaker.

Why does this happen, what different between these two cables?

Now if someone says it's a ground loop. I don't think it's possible. Ground loop is the difference between ground points in the system.
My only system is the amp, grounded on super clean sanded oem ground point stud with 0 gauge ofc wire.
So it's like, there can't be a loop, because there's nothing to loop with. Its one single audio component connected right now, which is the amp.


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## Slave2myXJ (Dec 18, 2021)

Is the body of the amplifier touching the body in any way? Try the opposite...

Most "shielded" cables are anything but. The braided shield is connected to the "-" terminal within the cable, and even worse, on both sides of the cable, creating the potential for a ground loop. This is why it's advised to ground the HU to where the amplifier is.

The next step up, the shield is only connected to the "-" terminal, making it a "directional" cable. It will have some indication that one end is different than the other; often times an arrow following the general convention of grounding the shield to the source. These remove the ground loop issue.

The proper way to do this, as is done in professional audio and generally speaking, "the real world", is to connect the shield to ground, entirely separate from the signal wires.

If you take a look at a NVX LOC, often times they have a selector switch for "Ground Isolation"; ground-tied, 200 ohm resistor or isolated. High-end sources, such as a LOC or DSP, have isolated outputs, completely eliminating the potential for ground loop issues. With isolated output and isolated input, you can use twisted pair cables. Twisted pair + separate ground wire is the "ultimate" (see CAN wiring), but if it's twisted-pair and shielded, and doesn't at least have a "direction" to the cable, run...

Most head units do not have isolated outputs, therefore twisted pair isn't helpful, so you have to rely on plain ol' shielding to keep the noise out. Ferrites have their place, but you either have to truly know what you are doing, or try configurations until you get improved results. The can make your problems worse just as easily as they can reduce it...

Your mentioning of noise when you tweak on the RCAs at the source; that's suspect to me. But I agree with your last; it should be quiet with an external source. Try flipping whether the case is grounded or not from what you have now, as I mentioned at the beginning. If so equipped, the resistor trying the inputs to ground on the amp may be suspect...


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## Bmwe39528i (9 mo ago)

Slave2myXJ said:


> Is the body of the amplifier touching the body in any way? Try the opposite...
> 
> Most "shielded" cables are anything but. The braided shield is connected to the "-" terminal within the cable, and even worse, on both sides of the cable, creating the potential for a ground loop. This is why it's advised to ground the HU to where the amplifier is.
> 
> The next step up, the shield is only connected to the "-" terminal, making it a "directional" cable. It will have some indication that one end is different than the other; often times an arrow following the general convention of grounding the shield to the source. These remove the ground loop issue.


The amplifier is absolutely not touching anything, it's sitting on plastic right now.

The thing is, I don't even have the headunit connected right now, while I'm trying to isolate and troubleshoot the problem.

From what you're saying, I should be able to just ground the outside of the rca connector to where amp is grounded and the noise should disappear, right? 
Because one side or rca cable is now plugged in the amp, and the other side is not connected anywhere for testing purposes.
So if I simply ground the other side of rca on amp ground, static should be gone?

Before I disconnected the headunit, it was grounded exactly st the same point where thr amp was grounded. But I still had static in all speakers. Any idea why?

As for directional cables, I do have one spare like that. It has arrows. Arrows point from headunit to the amp. The same story. I get static with it. Whether connected to both sides, amp and headunit, or only amp alone.

Any plausible explanations for this?
If I


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## Slave2myXJ (Dec 18, 2021)

If your amp is designed for ground-tied inputs, then yes, you could probably just ground the outside electrode. Measure resistance between the input and the case of the amp. Also, any of the switches or potentiates in the input section, either selectors or crossover are suspect as well. As mentioned, amps have various circuits to either tie the inputs to the case, or to isolate it from them. 

If it's getting noise with the vehicle off, the amp is highly suspect. If it only does it with the vehicle on, I'd be using my worst pair of rca cables as an antenna to find the source of the noise...


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## Bmwe39528i (9 mo ago)

It's my fifth amp at this point, so I highly doubt it's the amp. It's also a highly reputable amp, RD400 Jl. Not some no name brand.

I'll have to double check this one, but I believe it's only with the vehicle on.
How do I use rcas as antennas to find the problem? 
Please share!

Still pretty interesting that noise is not there if I plug into the amp the rca to 3.5mm adapter, instead of rca to rca cable. I'm not sure how that can be explained?


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## ItsonlyaHONDA (Sep 9, 2021)

Did you run your RCAs through the same route as the first time. 
If not I second burning the car for an insurance claim. Lol 😆 jk but maybe you should consider noise canceling headphones instead 🤣


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## Bmwe39528i (9 mo ago)

Slave2myXJ said:


> If you take a look at a NVX LOC, often times they have a selector switch for "Ground Isolation"; ground-tied, 200 ohm resistor or isolated. High-end sources, such as a LOC or DSP, have isolated outputs, completely eliminating the potential for ground loop issues. With isolated output and isolated input, you can use twisted pair cables. Twisted pair + separate ground wire is the "ultimate" (see CAN wiring), but if it's twisted-pair and shielded, and doesn't at least have a "direction" to the cable, run...
> 
> Most head units do not have isolated outputs, therefore twisted pair isn't helpful, so you have to rely on plain ol' shielding to keep the noise out. Ferrites have their place, but you either have to truly know what you are doing, or try configurations until you get improved results. The can make your problems worse just as easily as they can reduce it...


Could you please provide a link for the device you're referring to - NVX LOC?
This is interesting. If I install this device, it goes after my amplifier, and clears up the signal sent to my speakers? I'd gladly buy it.

Also wondering what do you mean by (see CAN wiring)?

So what you're saying, I need a headunit with isolated output?
Or instead a DSP or NVX LOC to fix it?

I see what you're saying about ferrite chokes. I had no idea what I was doing, I just put them on all the wires I could think of, and they didn't help. Maybe there's a special way they need to be installed.


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## Bmwe39528i (9 mo ago)

ItsonlyaHONDA said:


> Did you run your RCAs through the same route as the first time.
> If not I second burning the car for an insurance claim. Lol 😆 jk but maybe you should consider noise canceling headphones instead 🤣


Lol no dude! Like I said, I only connected 1 single rca. 1 rca instead of 4. So only one channel, instead of 4, to isolate and test the issue.
I didn't even run it anywhere at this point. I just connected one rca end to the amp, and the other end I didn't even connect anywhere, just have it hanging out my trunk, so it doesn't pick up any interference inside the vehicle.
Other than that, I only connected speaker wire for front left speaker (2 wires total, positive and negative).
This way im only testing one channel at a time.
I really gotta do a video on this, cuz maybe I don't explain things well.


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## ItsonlyaHONDA (Sep 9, 2021)

Why not run Bluetooth straight into your amp and bypass the head unit.


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## Bmwe39528i (9 mo ago)

That'd be ideal!
Since I only play music from my phone via Bluetooth, headuhit doesn't matter for me.
How can I bypass the headunit?
Some Bluetooth device that connects to my amp via rca?
Would that not negatively affect music performance?
Please share the device I can use and I'll look into it!


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## ItsonlyaHONDA (Sep 9, 2021)

No it won't negatively affect the performance. Yup Bluetooth to RCA in. Find a higher quality one like the Audison B-con I think it's called. I'm considering getting one too. There was a conversation today about it









dongle for streaming android audio to dsp


just finished a build, same old story, due to the integrated media system on the car I was forced to hook up the dsp to the factory amp speaker outputs. Im using a minidsp 8x12 that has optical and coax digital inputs, i need to find a solution to be able to send clean signal to the dsp from an...




www.diymobileaudio.com


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## Slave2myXJ (Dec 18, 2021)

What you replaced the OEM battery ground? Not inspected, replaced?

And I apologize for likely asking the same question you recently answered, but does it do it with the engine off as well?

Controller Area Network (CAN) is used in planes, trains and automobiles to move information around the vehicle...

The NVX device won't work for what you want, just a reference to the functionality...


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## Bmwe39528i (9 mo ago)

I replaced the battery cables and the ground cable in the trunk with this 0 gauge OFC cable

KnuKonceptz Kolossus Flex 0 Gauge OFC Power Amp Wiring Kit KnuKonceptz Kolossus Flex 0 Gauge OFC Power Amp Wiring Kit : Amazon.ca: Electronics

Yes, it does it with the engine off!
So I'm just uploading a video right now that I will share.

*BUT I MADE SOME PROGRESS JUST NOW*

I tried grounding the rca cable's outer jack shield, and the noise disappeared!!

Yeah, unbelievable, car off, engine off, amp is the only thing powered on. Powers front speakers. No noise.
Then I plug the rca cable into the amp, only 1 cable, and the front left speaker and tweeter are making the static noise!

Now I carry the other end of the rca cable (disconnected end) with me to the door. That's where I also run a ground cable from the trunk grounding point.

I put my ear next to the speaker and tweeter, and as soon as touch the metal jack of the rca with the ground wire, the problem disappears!

I have yet to try it with headunit connected and engine running, but so far this is great progress!

I also received the very expensive blue jeans rca cables, and they did the exact same thing.

Now I wonder if you were right about what you said with regards to the shielded cables. That in fact they're not shielded at all, because the shielding is connected to the ground of the rca cables and thus it created a ground loop inside the cable??

This would be insane. Does it mean no rca cable is properly grounded/shielded?
Like I don't get it, when I plug one end of the rca cable into the amp, doesn't the amp provide ground? Or when amp and headunit are connected together via an rca interconnect, and both amp and headunit are grounded in the same location, don't they both (amp and headunit) provide ground to the rca cable??


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## Bmwe39528i (9 mo ago)

I feel you're sharing lots of useful information, but I'm not knowledgeable enough to understand it all.

When you say

_The proper way to do this, as is done in professional audio and generally speaking, "the real world", is to connect the shield to ground, entirely separate from the signal wires_

What do you mean exactly?
Like running two separate cables per channel? One cable with signal wire, the other cable with ground wire?

I don't think I can measure resistance on the case of the amp, because it's painted. Unless I scratch the paint on it?

_If your amp is designed for ground-tied inputs, then yes, you could probably just ground the outside electrode._ 

What does it mean an amp designed for ground tied inputs? Aren't they all this way? Sorry for asking so many questions...


_Measure resistance between the input and the case of the amp. Also, any of the switches or potentiates in the input section, either selectors or crossover are suspect as well. As mentioned, amps have various circuits to either tie the inputs to the case, or to isolate it from them._ 

My amp case doesn't seem to be conductive.
And there aren't many switches there.


It's set to 4 channel, low input, all HPF are off, turn on mode set to REM, input set to stereo.

_If it's getting noise with the vehicle off, the amp is highly suspect. If it only does it with the vehicle on, I'd be using my worst pair of rca cables as an antenna to find the source of the noise..._

It's literally my 5th amp. High quality, highly rated on crutchfield. I mean who knows, maybe the 5 amps were bad, but how can I tell for certain?


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## Slave2myXJ (Dec 18, 2021)

No, I highly doubt you've had 5 bad amps. With the vehicle off, if you still have noise, it's either the amp, or a ground loop... It's pretty hard to have a ground loop with just one device, so you can understand my train of thought... Having the RCAs disconnected one the signal end is all but an antenna, so you grounding it and the noise going away is good. Now, you should be able to hook up your head unit to it and be noise free... The output of your head unit _should_ be tied to ground inside...

It's the input side of things that allows the crap RCA cables we get to work. If your RCA cable doesn't a ring terminal coming out from the body of the cable, to be connected to ground, it's not a properly shielded cable. Next step down is directional, with the shield connected to the "-" on one end only, generally the source because of the above, it's tied to ground. Non-directional shielded cables are anything but; they're a ground loop waiting to happen. Only because the inputs on high-end gear are not tied to ground does all this work. 

With the car off, and absent any other noise sources, such as LED drivers, stepper motors, etc, none of this _should_ matter. What you're saying leads me no to believe there's an issue with the head unit. Check the resistance between the shell of the RCA connection and the case and report back...


----------



## Slave2myXJ (Dec 18, 2021)

Now one to advocate throwing money at a problem, if we can't get this fixed, this may be worthwhile if for nothing more than the support that would come with it... 









Noise Gate Module


The ARC Audio NGM (Noise Gate Module) is a must-have for any High end or OEM integration audio system. Today’s factory audio systems continue to offer more challenges while installing aftermarket audio components into your new Car or Truck.




www.arcaudio.com


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## Bmwe39528i (9 mo ago)

Slave2myXJ said:


> Now, you should be able to hook up your head unit to it and be noise free... The output of your head unit _should_ be tied to ground inside...
> 
> Check the resistance between the shell of the RCA connection and the case and report back...


I'm curious why you think I should now be noise free? I haven't changed anything.
All I done was to disconnect the headunit to isolate the problem.
I just connected the headunit back, with car off but ignition on, it's the same problem, same static.

Highly doubt it's the headunit.
It's alpine headunit, less than month old.
Resistance between headunit body and rca ports is 0.

I was just following the troubleshooting diagrams, where they said to disconnect rca cables from the headunit but leave them connected to the amp and test for noise. And then disconnect from the amp as well, and if noise disappears, it indicates a caulty cable.
But you're saying cable is not faulty, it's just that now rca act as an antenna. Which makes sense.


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## Slave2myXJ (Dec 18, 2021)

I am by no means what-so-ever even remotely competent in that which we speak. After 251 posts, just trying to help... My thinking that it _should_ work after connecting it to a head unit is that the RCA outputs on the head unit should/are connected to ground. _Should_ be no different than grounding the cable out like you did, and eliminating the noise. I assumed we were past a bad cable, same as we're past a bad amp... 

My next question is, what's the resistance between the radio shell and the radio negative wire? Is the radio shell touching any metal when installed? I'm looking for ground loops basically... A difference in ground potential between two points that causes current to flow, thereby creating noise...


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## ItsonlyaHONDA (Sep 9, 2021)

Lol should I say it again. ❤‍🔥 insurance claim.


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## Bmwe39528i (9 mo ago)

I agree with you. I think we're past bad amp, past bad headunit and past bad rca cables.

That's the weird thing. When I connected the rca to the amp, and had the static, by grounding the other end of the same rca to a ground wire running from trunk ground, it stopped the static.

Now this is the exact same ground wire I'm using to connect to the headunit connector.

BTW the static gets worse if I turn the volume higher.

Let me share some more measurements and observations.

Test 1 - adding a Jensen transformer between headunit and amp doesn't seem to do anything.

Test 2 - adding an inline rca ground loop isolator does not seem to do anything.

Test 3 - Resistance between body of the headunit and each of 6 output rca ports - 000.1 This is with car off

Test 4 - Resistance between amp grounding point in the trunk and body/rca ports on headuint - 000.3 - 000.4

With car off, when I plug the other end of the rca cable connected to the amp into the headunit, the noise goes away, just like in my test prior, where I was grounding the rca cable and it worked.
After that noise goes away, I still hear a very tiny bit of static. So I guess I forget how bad the static was before.

So when I remove the cable from the rca and I hear the static, it's noticeable. And when I plug rca cable into headunit, noise almost goes away. It's easy to tell. But then if I keep listening, I probably get used to it and now can hear it lol.

Now I turn ignition to "on". Resistance between ground point in the trunk and headunit jumps to 054.5 ohms. Not sure if it's normal?

So far the headunit is not connected to Bluetooth. If I move the volume dial on the headunit all the way up or down, it doesn't change.
Now if I pair my phone to the headunit and turn volume up while a song is on pause, static becomes louder. Resistance between rca ports and headunit is still 000.1 or 000.0 with music playing.

With headunit paired to my phone, resistance between main ground and headunit is 090.0 ohms
If I play music, resistance goes to 096.0

I guess my next step, I can try one more time to power the headunut from the car battery, with vehicle off and ignition off to see if I can hear the static. But the static is very faint now, maybe I just didn't notice when/how things improved.

But still interesting that the rca to 3.5mm jack/adapter doesn't even do any noise when plugged into the amp by itself or plugged to my phone at one end and amp on the other end.


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## Slave2myXJ (Dec 18, 2021)

You can't read resistance while the circuit is powered, so those high values you're getting aren't real...

Powering the head unit directly from the car battery with the ignition off would be a good test.


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## Bmwe39528i (9 mo ago)

Powered from battery with ignition off, it does the same static, but pretty faint. Overall, I'd be happy to live with it!

But now the final test. I start the car and can hear the good old whining through the speaker and tweeter lol! This is with one rca connected, BJC LC-1.

Well I gotta switch back to Amazon cables and see if whine goes away..


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## Slave2myXJ (Dec 18, 2021)

Were you powering the head unit directly from the battery when you started it here this last time? How did it sound with just the ignition on? It would be easy enough to power the head unit directly from the battery using a relay triggered by the factory wiring. Adding a capacitor to the newly added power wire would further help to reduce noise. But before I did that, I'd probably try moving the head unit around to see if I could identify the cause of the noise...

An old XJ trick you can try, may help in this situation; add a short ground wire from the metal structure of the dash over to the sheetmetal body nearby...


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## Bmwe39528i (9 mo ago)

This last time, I tried both from ignition wire and from battery.

If I don't start the car and just play music with ignition on, there's no noise.
Noise starts creeping in when I start the car. And even then I'm not sure it's very audible. Once I rev the engine up, that's when I can really hear the whine in the tweeter and some in the speaker too.

I also tried connecting through this, what looks like a capacitor, thoigh it is an alternator noise filter









Helix CAP 33 Car Audio Alternator noise supressor capacitor 12v Fast Dispatch | eBay


Find many great new & used options and get the best deals for Helix CAP 33 Car Audio Alternator noise supressor capacitor 12v Fast Dispatch at the best online prices at eBay! Free shipping for many products!



www.ebay.ca







I already have a 150 amp alternator filter by the alternator. And I tried using this Helix 33 filter to clean up my wiring powering the headunit, I tried both through ignition wires and through battery wires. Didn't do a thing.

But given I have new battery, new alternator, upgraded grounds and power wires, and alternator filter, it's highly unlikely I would have interference from power lines.

I'll try the extra ground you're suggesting just in case.

I'll try moving the headunit to the trunk and see if anything changes.

I mean the whine seems small right now, nothing like what it was when I started this thread. But it's definitely still there.



I think I already tried adding extra grounds, all grounds seem to have almost zero resistance.

I pretty much did the BIG 3 upgrade, except I didn't change the power wire running from under the hood to the trunk.

Things are probably getting better, but weirder too. Like that time, not long ago, when the whine was actually coming from the wires themselves!



I appreciate you sticking around and trying to help though all this weirdness that doesn't make sense.



What do you think about the Bluetooth dsp amp?






Dayton Audio - DSP-408 4x8 DSP Digital Signal Processor for Home and Car Audio


DSP-408 4x8 DSP Digital Signal Processor for Home and Car Audio




www.daytonaudio.com







It would eliminate the headunit from the system, and the rca wires going from headunit to amp.

What are your thoughts on just going headless?

So far the only static and whine free and consistent successful result I have is when I feed headunit from my phone. No problems to speak of. This is where I'm trying to lean now. Figure out a way to just use my phone. I only play music from my phone anyway, so if I can do without headunit, it's even better.



The only other idea I have, is there's a short somewhere in the system. I don't know how to find a short in a running system. I mean it's easy to find a short when car is off, by just connecting tester light between battery negative terminal and battery negative cable. Mine lights up. But I also tested with a multimeter. The draw is small when the car goes to sleep after 16 minutes. Draw is like under 100 mA.

Now maybe something is shorting when the vehicle is running? I'm not sure how to find that.

I can install these filters everywhere. Between amp and battery cable, between headunit power and headunit.

Install Bay IBNF50 Noise Filter 50 AMP Each https://a.co/d/6xIlWwX

I mean there's definitely some feedback loop somewhere, cuz I hear that whining though the speaker. So something is feeding back. But I can't understand how. Headunit with 3 wires lol. Ground is taken directly from the amp ground. And power is taken from either the battery, same place where amp is powered, or from the ignition. How in the world I can a ground loop I don't understand.



You said I cannot measure resistance when car is running and power is flowing. But thats my only other guess. I'm thinking when the car is running, if there's a short somewhere, it could be feeding power into the ground wire and causing feedback. I wonder how to test for that, in case my grounds are getting energized.


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## Bmwe39528i (9 mo ago)

And even the Jensen transformers and inline rca filters don't seem to help with this last bit of whine 






CI-2RR | Jensen Transformers


The unbalanced stereo design begins with gold RCA connectors to ensure optimal signal transfer. These are housed in a rugged steel enclosure that is fitted with screw-down flanges for easy installation in racks, under shelves or attached to cabinetry. The magic inside comes from two high...



www.jensen-transformers.com


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## Bmwe39528i (9 mo ago)

_A quick test for a ground loop is to pull the RCA out of the amp until only the center pin is touching. If the noise goes away, you have a ground loop. A remedy is to install a ground loop isolator. A ground loop isolator is a device with a transformer in it. The audio signal is transferred through the magnetic interaction of the transformer windings. There is no direct electrical connection between the input and output cables. With no electrical connection present, current cannot flow. The drawback of a ground loop isolator is that it can detrimentally affect the frequency response of the signal passing through it._









Differential Inputs are Your Friend


One simple technology that has helped to reduce noise issues is the inclusion of differential inputs of modern amplifiers and processors.




www.bestcaraudio.com





That's another head scratcher. If this was a ground loop issue, these steps would've shown it. But the ground isolators don't seem to fix the whine. Not does connecting rca without the outside shield touching.

I was thinking of getting a differential amp instead and running twisted pair rca cables, but not even sure if the headache is worth trying it.

I'll give crutchfield a call and see if they have a bluetooth amp in mind. I couldn't find any on their website. The goal is to avoid connecting rca cables to amplifier input, because this is what gives me noise.


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## ItsonlyaHONDA (Sep 9, 2021)

Get a Helix with a HEC slot and call it a day. The amount of money you have spent already on the issue would have paid for multiple already.


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## Bmwe39528i (9 mo ago)

Do you have a link for the unit you recommend? A video to how it works, or maybe an article? I tried googling but im not finding much. I don't mind getting Helix. That'd be available in Canada hopefully.
I've never heard of Helix or HEC


Called Crutchfield, the only amp they have with Bluetooth is ST4.1000DB
Not sure if it's good enough. It's like only $200 on Amazon and says it's for ATV??
But it's apparently 90 rms per channel which is pretty good. Not sure if the rmp is real, because it only has one fuse of 30 amps


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## ItsonlyaHONDA (Sep 9, 2021)

HELIX Processors since your in Canada I have no idea abouts the distributors out there.


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## Bmwe39528i (9 mo ago)

Thanks, from that link their lowest dsp is HELIX DSP MINI MK2








HELIX DSP MINI MK2


Digital High-Res 6-channel signal processor with 96 kHz / 24 Bit signal path




www.audiotec-fischer.de





It's 6 channels. All others have more channels.

It's available on ebay for just over $600 CAD








HELIX DSP MINI MK2 6-CHANNEL, THE LATEST DSP UNIT, DIGITAL-IN, ACO, BRAND NEW | eBay


Find many great new & used options and get the best deals for HELIX DSP MINI MK2 6-CHANNEL, THE LATEST DSP UNIT, DIGITAL-IN, ACO, BRAND NEW at the best online prices at eBay! Free shipping for many products!



www.ebay.ca





Looks like to make it bluetooth, I need a specific module for the same model, just over $300 CAD









HELIX BT HD FOR DSP MINI MK2,HIGH DEFINITION BT AUDIOSTREAMING MODULE NEW | eBay


Find many great new & used options and get the best deals for HELIX BT HD FOR DSP MINI MK2,HIGH DEFINITION BT AUDIOSTREAMING MODULE NEW at the best online prices at eBay! Free shipping for many products!



www.ebay.ca





I can give this a shot if there's no better products on the market, such as amp and dsp 2 in 1, which would make it less complicated.


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## ItsonlyaHONDA (Sep 9, 2021)

Bmwe39528i said:


> Thanks, from that link their lowest dsp is HELIX DSP MINI MK2
> 
> 
> 
> ...


I suggest you find a local dealer if possible. If you get it from ebay you will have no warranty and no support if needed. 









Distributors







www.audiotec-fischer.de


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## ItsonlyaHONDA (Sep 9, 2021)

Bmwe39528i said:


> Thanks, from that link their lowest dsp is HELIX DSP MINI MK2
> 
> 
> 
> ...


And they do have anp/ DSP combos 









HELIX Amplifiers


High-end amplifier from HELIX. ✓ Over 30 years of experience ✓ Made in Germany ✓ Car-Hifi for highest demands




www.audiotec-fischer.de


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## ItsonlyaHONDA (Sep 9, 2021)

But not all have a HEC slot


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## Bmwe39528i (9 mo ago)

Oh yeah only a couple of them do.
The cheaper one is $2000 CAD
HELIX P SIX DSP MK2 + DIRECTOR HIGH-END 6-CHANNEL PROCESSOR-AMPLIFIER BRAND NEW | eBay

I guess I'll try the Bluetooth $50 dongle, then these cheaper Bluetooth dsp and bluetooth amp

- Soundstream Stealth Series ST41000DB 4 Channel Class D Amplifier

- Dayton Audio DSP-408 4x8

Unless there's a specific reason why Helix would have a better chance of taking care of the whine?


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## ItsonlyaHONDA (Sep 9, 2021)

The Helix is better at everything. But I don't know if it's going to help with your whine from the head unit.


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## Bmwe39528i (9 mo ago)

Yeah, the thing is that I can't really get the benefits of DSP anyways, because I already have crossovers in my doors. Unless I rip up the car again, rerun the wires to the speakers and tweeters and throw out the crossover boxes. It I were to do that, I'd replace the CCA wires for my speakers with OFC wires this time.
So I'll try the other options first. If they work but just have issues cuz they're lower quality, I can upgrade to Helix amp with Bluetooth.


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## ItsonlyaHONDA (Sep 9, 2021)

You should replace anything that's CCA regardless lol it's junk dude. Noise is probly coming from there


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## Bmwe39528i (9 mo ago)

Well now you're pushing it!😂


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## Slave2myXJ (Dec 18, 2021)

Mondays... 

If it's completely quiet with the engine running and the RCA cables disconnected, there's a good chance you could fix this by streaming directly to the amp/dsp, or using a digital connection. Finding a head unit with a digital connection is the trick though...

Have you had a chance to try it with the head unit at the rear of the car? Doing so would reduce some likely culprits, such as spark plug wires, stepper motors in the gauges and/or HVAC box, HID lights, etc.

When you did your upgrades to the OEM wiring, what have you done to the ground wire running from the engine to the body/frame/battery? No clue exactly how yours comes factory... Does it have the braided ground strap running to the firewall?

The passive crossovers are a great antenna. I can't think of anything in the doors that should be allowing current to pass when it's just sitting there doing nothing, but if there is... Doors are not a good place for them, particularly from an environmental standpoint. Water is bad juju...

Finding shorts, stray current, noise, etc is a royal PITA, particularly with a "smart" car that's doing stuff you're not asking it to do. Not sure I have a good answer for "how" other than to isolate circuits, turn things off, pull the fuse for the dash, disconnect the alternator, etc. Unfortunately you can't bypass the spark plug wires. Any aftermarket parts?


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## Bmwe39528i (9 mo ago)

So I got the Bluetooth dongle.

Test #1
Bluetooth feeding the amp on channel 1.
Vehicle completely off.
Headunit disconnected and rcas disconnected.
Music plays but when I put it on pause, there's static in the tweeters and more of a hum in the speaker.
Asked my gf to listen, she says it sounds like an old VHS on pause.

Test #2
Unplugged the rca cable from the dongle. Noise got a little bit quieter. Maybe by about 20%

Test #3
Unplugged rca cable from the amp. Noise got a lot quieter, maybe by 80%, barely audible. But still there. Though I'd be totally happy with this level.

Test #4
Removed power from remote wire for the amp. Noise gone completely 100%.

Tried another 50 amp filter on the power going to the amp. 0 change in results.


2015 e550 4matic


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## Bmwe39528i (9 mo ago)

Tried with headunit in the back. Didn't start the car yet, just testing the hum/static.
With headunit in the trunk and car off ignition off, still hear the static in speaker and tweeter.
Next gonna test with direct aux phone connection instead of bluetooth.
Gf says it sounds like a DVD player connected to a TV and put on "pause" when the volume is loud.


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## Bmwe39528i (9 mo ago)

I just feel it's related to some kind of a short.

So next test I connected the Bluetooth dongle.
One rca cable between dongle and amp. Car and ignition off.
No noise at the speakers or tweeters. Actually I hear some faint noise, but it's like white noise. So it's completely fine and doesn't really have any pitch to it.

This is with the dongle not powered on, I.e. not connected to the power supply.
As soon as I connect it to the power supply, I get the static in speaker and tweeter!



So this kinda tells me, it has to do with power. I.e. the static.

I also have a battery tender connected to the positive and negative terminals of the battery.

So the next test I do, I disconnect dongle from power supply and keep the rca cable plugged in dongle and amp.
Listen for noise - no noise.
Plug in the battery tender - can hear the noise right away!


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## Bmwe39528i (9 mo ago)

I thought to power the USB dongle with a power bank, as it needs very little, but power banks wouldn't work. It would turn off almost right away. Maybe power banks give too much power.

So I used the supplied USB cable to power the dongle with USB port from headunit.
It worked, no uptick in noise. Pretty much just very faint whine noise which just sounds clean and doesn't bother me. Extremely faint.
But then if I played music, I kinda heard some weird noise coming from the tweeter, almost like some interference. I turned on high pass filter and set it to 120 and I don't know if it's placebo or not, but that interference disappeared. So was playing clean and was quiet when on pause, no more static!

Then I decided to try to play music from headunit. Flac wouldn't play from USB, but mp3 played fine. Again, somehow all noise was gone as on the dongle, and really no noise and no static when paused. Just very faint and very acceptable white noise, correlating with volume level.

Then I tried BT from my phone to headunit, and that worked fine too. Hmmmm....where did the static go....

All these tests were done with car off, and it was actually in a sleep mode. X5 E53 goes into sleep more after 16 minutes of inactivity.

I then woke up the car by turning the key to ignition, but without starting. Definitely static got significantly worse. Turned the key off, so now the car was off but out of sleep mode.
I think the white noise might've increased very slightly, but nothing like when key is turned to ignition.

So from off I turned the key back to ignition, but it seems it didn't get bad this time. 

So I'm not exactly sure what's going in, but the static it pretty much gone at this stage.
Now I just need to start the car to see if whine is there or gone as well. As I'm not sure, maybe whine is just the static getting amplifier with rmp. At 1 a.m. I decided not to start the car and not to wake up neighbours but will continue testing tomorrow. 

It looks like the car is extremely sensitive to any voltage/current. Any electricity seems to spike the static. Be it ignition on, charging the battery or plugging USB dongle into house outlet. Tomorrow I'll try powering the dongle from a cigarette charger to USB adapter, instead of powering through headunit.

But it's interesting, the current somehow gets introduced into the system and makes things worse.
I can understand the battery tender making static worse, since it feeds power directly to the battery.

But i really don't understand how the power to the dongle makes static worse.

The dongle is connected with 1 rca cable to the amp. That's it. The only other wire to the dongle is the power adapter that I plug into house outlet, and the noise automatically appears. So it's like, the power for dongle gets transferred somehow on the rca cable, and probably pollutes the shield/ground of the rca?
I'm not smart enough to know what's going on. But the vehicle is hyper sensitive to any voltage.
So in this case, when I rev the car, it makes sense that it whines, as more power is going into the ground somewhere. It's like, maybe there's a short somewhere.

Also weird that the 150 amp filter by the alternator and 50 amp filter on the amplifier doesn't take care of this interference.

I'm thinking that maybe now an oscilloscope is in order?


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## Bmwe39528i (9 mo ago)

Slave2myXJ said:


> Mondays...
> 
> If it's completely quiet with the engine running and the RCA cables disconnected, there's a good chance you could fix this by streaming directly to the amp/dsp, or using a digital connection. Finding a head unit with a digital connection is the trick though...
> 
> ...


Well ideally I'd like to avoid a headunit.
But I heard it's also the type of amp. Amp had to be differential instead of rca(unbalanced, single ended). I'll have to do some more research on that.

The oem ground wire from engine block to chassis was a black wire, probably 4 gauge.
I replaced it with 0 gauge ofc cable. The length is probably no more than one foot .

I'm not sure I've seen a cable running to the firewall.

Crossovers ended up in the door cuz my buddy was installing them for me and he said it was fine. Before that, I had now idea what a crossover was. I still don't know 

Now the next step, I can remove one of the crossovers/tweeters/speakers combo from the car and keep testing that separately.

For aftermarket I have some stuff like rolls royce headliner, remote starter, front and back cameras, maybe something else.

Yes shorts would be hard to find in this situation. I wonder if oscilloscope would be of any help looking for frequency on the power wire, or whatever I need to look for on that device.


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## Slave2myXJ (Dec 18, 2021)

No difference between a short moving charge into the ground plane and a device doing the same thing. It's only when the ground plane can't dissipate the charge that voltage builds up. That's why I keep asking about grounds...


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## Bmwe39528i (9 mo ago)

I totally get your concern. I once bought an old 1998 5series bmw, and it wouldn't start no matter what. Lots of people looked at it, nobody could fix it. Changed half of the vehicle. Some mechanic said it had to be Immobilizer module, which was at least 2 grand to replace and program.
The vehicle had a cable between the chassis and the engine block that was corroded. So all I had to do was to use jumper cables, and ground a few points together. Body of the vehicle, engine and chassis, and the car started!

This is the ground wire I replaced on my current vehicle. Factory one was 4 gauge at most looks like. I installed 0 gauge, it's between the engine of the vehicle (engine mount) and the chassis.

The power supply for the Bluetooth dongle is so tiny, I don't understand how it could ever be possible for this little current not to be dissipated, given my amp is grounded to the body of the vehicle.


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## Slave2myXJ (Dec 18, 2021)

The Bluetooth dongle may just be providing a pathway for the noise. Doing a bit of research on this vintage of BMW, maybe not the exact vehicle, and they appear to have ground straps all over the place. One model had a ground strap on the exhaust system !!! Most likely candidates for the noise are the fuel injectors (seen a ground strap on those), the spark plug wires (seen a ground strap for those), fuel pump (seen a strap for that), HVAC Blower and stepper motors, such as the Idle Air Control Valve, power mirrors, perhaps the gauges in the dash. The add-on ground wire from the dash to the body would take care of the later. Making sure any ground straps you do have are in good condition would take care of the former two...


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## Bmwe39528i (9 mo ago)




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## Bmwe39528i (9 mo ago)

This is the ground I added when replacing old factory wire.


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## Bmwe39528i (9 mo ago)

I guess what I can do is plug the USB dongle to its power supply and try to add different grounds around the vehicle and see if the static goes away. This is without even starting the car.
Somebody suggested to me earlier getting Alldata subscription and going through each ground on the vehicle. That would imply ripping everything apart in the engine compartment and under the carpet...


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## Slave2myXJ (Dec 18, 2021)

I think I'd try pulling fuses to see if I could isolate it that way. May be an easier route to figuring out which ground is the problem...


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## Slave2myXJ (Dec 18, 2021)

But yes, disassembling, cleaning to bare metal, reattaching and sealing the grounds on older vehicle like this is never a bad idea. My XJ is only a few years older and there's a whole list of things that _should_ be done on the electrical system to keep it working well.


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## Bmwe39528i (9 mo ago)

I grabbed jumper cables and some extra wires and connected together all the main grounds I could think of.
Ground in the trunk where amp and battery is grounded to underdash metal reinforcement, to ground under the hood, to ground between engine and chassis, to strut tower bolt.
No luck, static is there if I turn on only the amplifier and plug the battery tender or the BT dongle, even with the car in sleep mode.
Maybe I don't know enough, but even if there was a ground missing somewhere, why does it make this static noise with the vehicle off?
All the grounds connected together in the vehicle cannot dissipate the extra 5v/100mA?

Tried starting the car, and the whine is still there.

I will power the BT dongle with its adapter and plug it into wall outlet. Then I'll try pulling all the fuses one be one to see if anything changes, with the vehicle off.

If that doesn't work, I'll probably just have to live with it and move on. I'm approaching a point where I have no idea what else to try.


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## Slave2myXJ (Dec 18, 2021)

Bmwe39528i said:


> I'm approaching a point where I have no idea what else to try.


You and me both...


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## ItsonlyaHONDA (Sep 9, 2021)

😈❤‍🔥 insurance claim


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## JohnnyOhh (Feb 19, 2015)

why do you keep changing the title of the thread? just curious.


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## Bmwe39528i (9 mo ago)

ItsonlyaHONDA said:


> 😈❤‍🔥 insurance claim


The vehicle is like worth 2k, all the time and effort and parts I've put into it are probably worth like at least 20k.
If I had to do it all over again, I would've purchased a brand new car. I just like working on my own car and fixing things, but not being able to fix something and there not being anyone who'd fix it for money sucks.


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## Bmwe39528i (9 mo ago)

JohnnyOhh said:


> why do you keep changing the title of the thread? just curious.


Just trying to have the title reflect the latest state of affairs. But more and more I feel I'm chasing my own tail...


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## ItsonlyaHONDA (Sep 9, 2021)

Bmwe39528i said:


> The vehicle is like worth 2k, all the time and effort and parts I've put into it are probably worth like at least 20k.
> If I had to do it all over again, I would've purchased a brand new car. I just like working on my own car and fixing things, but not being able to fix something and there not being anyone who'd fix it for money sucks.


I was just kidding, I dont actually want you to set your car on fire 🔥. But if you did just make sure you take a video 😉 so we can all watch. Lol I bet the static would go away then.


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## Bmwe39528i (9 mo ago)

What if I ground the battery negative cable on something outside of the car, like the metal frame of my garage door opener. Would that rule out bad ground in the vehicle?


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## Spud100 (Mar 30, 2015)

No "ground" in an auto situation refers to the body / chassis and the return to the non live battery terminal.


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## ItsonlyaHONDA (Sep 9, 2021)

Northsound said:


> I fought with alternator whine for weeks last summer on a Chrysler 300 and tried everything you listed pretty much. Just couldn't eliminate it no matter what i tried.
> In a last ditch effort i put 50 amp inline noise filters that i bought of Amazon between the battery and amps and voila, its gone! Now i have clean sound and no hair because i pulled it all out.😎


I just read this somewhere else. Have you tried this.


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## Bmwe39528i (9 mo ago)

Yes if you look at post #274, I posted a picture of 50 amp filter between the battery positive terminal and power wire for the amp.
This is in addition to 150 amp filter right after the brand new bosch alternator.

I guess these filters are required to clean up ripple and interference in the current.

And I think at this stage we're trying to figure out if my problem is caused by bad ground or "dirty" current. Having tried these amp filters, I'm pretty sure that this should not be a problem. But I guess I can get an oscilloscope and do another test to test for AC ripple, just to make 100% sure.
AC ripple is what can cause alternator whine from what I heard.

As to the ground, I'm not sure how to test if the ground is the problem.

My only other thought was whether it's possible to install a second power source system to insulate the audio system from the rest of the car. Like installing a second battery specifically to power just the amp. But I don't know if that's something that would work and if it's possible not to have a common ground and to avoid interference from my main system.


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## Slave2myXJ (Dec 18, 2021)

I can't find an article for it at the moment, but I remember reading somewhere that batteries themselves can put off noise. Also similarly referenced here 









2019 Genesis G70 - High-End Sound Quality - Accuton...


Here it is, one of the latest and greatest high-end car audio installs from Vanguard Automotive Design. This time, in a 2019 Genesis G70. Let me get this out of the way right now.. this car is awesome, and the Kia/Hyundai brands really stepped their game up over the past few years. Seriously...




www.diymobileaudio.com


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## JohnnyOhh (Feb 19, 2015)

edit:
removed comment for ignorance to battery noise emissions.


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## Bmwe39528i (9 mo ago)

That's interesting. Looks like in this case the DSP was picking up noise wirelessly from the battery, as it was located almost right next to it. I can definitely cover the battery with a piece of soundproofing foil. But I have previously moved the amp to the backseat, far away from the battery.

With the amp powered from the battery and the car off, there's no noise unless, for example, I connect that usb dongle to an exterior power source. Like when I plug the adapter into household outlet.
But if I power the dongle from USB port on the headunit, there's no noise (that's with the car off). But when I start the car, even if dongle is powered from HU usb port, I can hear a small whine, suggesting some interference is getting into the amplifier.
That's why I'm not sure if the battery can be causing it.
I'll double check again, but when I use my phone via rca adapter to send input into the amplifier, I don't have any noise or whine.

So maybe I'll just have to settle for using my phone via 3.5mm jack to play music.

But if the battery is causing any interference, what I'd really like to know if how to test for it. I haven't heard of having interference from battery if a filter is installed, like I did in my case.


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## ItsonlyaHONDA (Sep 9, 2021)

Bmwe39528i said:


> That's interesting. Looks like in this case the DSP was picking up noise wirelessly from the battery, as it was located almost right next to it. I can definitely cover the battery with a piece of soundproofing foil. But I have previously moved the amp to the backseat, far away from the battery.
> 
> With the amp powered from the battery and the car off, there's no noise unless, for example, I connect that usb dongle to an exterior power source. Like when I plug the adapter into household outlet.
> But if I power the dongle from USB port on the headunit, there's no noise (that's with the car off). But when I start the car, even if dongle is powered from HU usb port, I can hear a small whine, suggesting some interference is getting into the amplifier.
> ...


You know what I feel for you and your situation sux. 300 post and a grip of effort you have put out and no solution. I wish I could help. I say you find the quietest of all of the solutions and live with it. I would have quit a long time ago and just used headphones.


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## Slave2myXJ (Dec 18, 2021)

JohnnyOhh said:


> c'mon man..... ^^ this is not a thing. you go find that article... let us know.
> please don't post unless you have real information.
> 
> batteries themselves are quite sources of DC voltage. 🔋


Without a doubt, batteries are a great source of DC voltage. But we're not talking about voltage here... Did you even look at the post I linked to?


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## Slave2myXJ (Dec 18, 2021)

Lithium Ion Cell/Batteries Electromagnetic Field Reduction in Phones for Hearing Aid Compliance


“The Hearing Aid Compatibility Act of 1988 (HAC Act) generally requires that the Federal Communications Commission (FCC) ensure that telephones manufactured or imported for use in the United States after August 1989, and all ‘essential’ telephones, are hearing aid-compatible”. The...




www.mdpi.com


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## ItsonlyaHONDA (Sep 9, 2021)

Slave2myXJ said:


> Lithium Ion Cell/Batteries Electromagnetic Field Reduction in Phones for Hearing Aid Compliance
> 
> 
> “The Hearing Aid Compatibility Act of 1988 (HAC Act) generally requires that the Federal Communications Commission (FCC) ensure that telephones manufactured or imported for use in the United States after August 1989, and all ‘essential’ telephones, are hearing aid-compatible”. The...
> ...


Your first link was the genesis build log.


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## ItsonlyaHONDA (Sep 9, 2021)

Ha, my bad he referenced the situation... my bad.


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## ItsonlyaHONDA (Sep 9, 2021)

This is what he used to fix the noise






ResoNix Barrier – Moldable Noise Barrier – ResoNix Sound Solutions







resonixsoundsolutions.com





I think.


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## JohnnyOhh (Feb 19, 2015)

whoa mind blown, good link. love Motorola, btw.
so all the different currents being drawn from a battery at different rates/speeds generate noise, depending on the battery cell geometry.
this article appears to be related to cell phones and cell phone pouch LiIon batteries.

you think this applies to automotive (SLA) batteries though?
I guess it probably does ... since vanguard posted about it.
f me in the b hole. thanks for posting. i'm shocked batteries can generate EMI!



Slave2myXJ said:


> Lithium Ion Cell/Batteries Electromagnetic Field Reduction in Phones for Hearing Aid Compliance
> 
> 
> “The Hearing Aid Compatibility Act of 1988 (HAC Act) generally requires that the Federal Communications Commission (FCC) ensure that telephones manufactured or imported for use in the United States after August 1989, and all ‘essential’ telephones, are hearing aid-compatible”. The...
> ...


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## Bmwe39528i (9 mo ago)

Thanks for your contribution man! My case is definitely not simple, so something crazy like this could be the issue.

So I came back to the car, it fully charged, and now I don't hear the static in the tweeter if I have my battery tender plugged into house outlet.
I'm thinking maybe the battery is full and is not drawing power and hence it's not adding extra noise into the system.

Then I tried plugging the BT dongle power adapter into home outlet, and could here buzzing in the speaker.

Then I used a cigarette lighter in the trunk and powered the BT dongle with USB cord from cigarette lighter adapter, and there was no static or buzzing.

When I started the car, unfortunately I heard the faint whine again.

I removed speaker wires from the amplifier and tested for continuity between each speaker and battery positive and negative. All readings were infinite, do definitely there's no shorts where.

I guess I'll take it for a drive and see. Last time I thought I got rid of the whine, took the car for a drive and heard the whine.

Actually now when I first started the car, I was listening and heard no whine. But after a few seconds, I could hear the whine.

I don't know if it's something that builds up after a few seconds or what's going on.


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## Bmwe39528i (9 mo ago)

ItsonlyaHONDA said:


> This is what he used to fix the noise
> 
> 
> 
> ...


I'm not sure what exactly the product is made of, but I've got multiple products from Products

I guess it won't hurt, I'll throw some of them overtop my battery and see.


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## JohnnyOhh (Feb 19, 2015)

if you think the noise is being emitted by the battery, you can try a metal battery case, you would want enclose it in metal.
the resonix stuff has a layer of lead in it.

you can try aluminum foil as a test. wrap the the battery with aluminum foul, couple layers.
you can also wrap your DSP in it to shield that see if any of that helps.

if you're doing any of that though, make sure you do not short anything out.


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## Bmwe39528i (9 mo ago)

The way the battery sits, I don't really have a way to encose it in metal. But if you look at the picture, I can definitely throw some foil overtop and it will completely cover the battery. I don't have DSP but I can also put foil all around my amp.
I don’t have any foil sheets but this product has a layer of foam so I figure that should work?








STP Black Gold - The best Sound Deadening for cars


TP BlACK GOLD is used as a vibration-damping sound deadening coating in vehicles, agricultural machinery and other objects, which must meet particular requirements of effective sound and vibration reduction. The material is designed to be used at temperatures from -45 to 100°C;



stp-canada.com














Right now I'm testing with BT dongle vs phone.

So I use 4 rca splitter to 3.5mm jack.
4 rca cables go to 4 amp channels, and 3.5mm jack goes either into my phone or into the USB dongle.


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## Bmwe39528i (9 mo ago)

I was ready to give it a go.
Added a layer of the sound insulation I linked above.
I decided to change where I was attaching positive cable for the amp. No clue if it does anytning or not, but I was attaching positive higher up on the battery clamp, where the wires from the alternator return to power the battery, and also where it has a inline battery cable fuse that disconnects the battery in case of collision. No clue if this could've caused any problems or not, as it's all on the same clamp, but I changed it as per the arrow on the screenshot.





roll site

Then I readjusted amp gains to my phone as a source and took my gf for a ride lol. We both listened and I set the music to be as loud as possible.
Even with music on pause, there no noise, no whine, no static and no buzzing. There's a tiny bit of white noise, which is more than acceptable to be and barely audible with my ear stuck on the speaker/tweeter.

The other thing I did was to move my second amp filter.
Instead of it being as I pictured previously, between the battery and the positive cable for the amp, I moved it up the chain and installed it in between the splitter fuse (where 0 gauge wire splits to power 2 amps) and the amplifier.
So it's kinda weird in a way. I way 0 gauge wire running to the fuse where it splits, and then I have this 50amp filter going between the wire splitter and the amp.
It's funny because it's like 10 gauge wire.

My amp's manual said to install a 40 amp fuse before the amp, which I did. And the 50 amp filter seems ok then.
But then the manual for the amp says that it should be powered with a minimum of 4 gauge ofc wire. So I don't know if I did any good replacing 0 gauge wire for the speaker amp with this filter lol. It only has 10 gauge wire I believe. I don't understand these filters. Their wires are tiny. You get told to use 4 gauge or 0 gauge wires for your connections, and then they suggest you put these filters with tiny wires. Maybe it doesn't matter because it's so short?

Now last thing I want to do before declaring victory is to connect the second amp and sub.

How can I feed signal to the 2nd amp?
I have two rcs pre outs on my first amp, so I was wondering if I should use them?









Or I can add another splitter to this splitter and have 6 rcas split from one 3.5mm jack. Is that ok? Does it matter to split the blue/red rca plugs equally or not?


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## ItsonlyaHONDA (Sep 9, 2021)

You could use your outputs of your amp or the splitters. Either will work. Or you can get a DSP that only needs 1 input to control your whole system lol 😵‍💫


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## Bmwe39528i (9 mo ago)

The only reason I'm not going with dsp is because I already have crossover for my speakers and tweeters in my doors. So dsp wouldn't do anything for me I think.
Unless I take apart the doors again and rewire everything.
I want to be done with this project, as you have witnessed almost first hand, it's been pretty exhausting 
All I want is to have no interference and enjoy the car and the music. And right now I'm 100% happy with the sound, just the bass is missing.

After all I've learned, I can do full throttle on my other car, E39.
I plan on doing a ton of retrofits and upgrades on it so the car will be fully stripped and soundproofed as well.
In that case I can do helix bluetooth dsp+amp and any other components.


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## ItsonlyaHONDA (Sep 9, 2021)

Bmwe39528i said:


> The only reason I'm not going with dsp is because I already have crossover for my speakers and tweeters in my doors. So dsp wouldn't do anything for me I think.
> Unless I take apart the doors again and rewire everything.
> I want to be done with this project, as you have witnessed almost first hand, it's been pretty exhausting
> All I want is to have no interference and enjoy the car and the music. And right now I'm 100% happy with the sound, just the bass is missing.
> ...


You'll be fine using the output of your amp then. It's just an internal Splitter actually meant for an other amp.


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## ckirocz28 (Nov 29, 2017)

Bmwe39528i said:


> Installed OFC for ground and power wires going to the amp, I think the whine is gone.
> Also, I used 0 gauge wires from battery and ground to the amp. I used 4 gauge to 0 gauge reducer connector to use 0 gauge wire.
> 
> Installed an extra fusebox and fused both amps at 40 amps as per manual from RD400 JL.
> ...


I have used Stinger 4000 series rca's and found them to be quite good, but, I also had to squeeze the outer ring to tighten it up a bit and open the split center pin just a hair. This might be something to try with your cables, if they have a split center pin. Both of those contacts are equally important. Very carefully use a knife to open up the center pin just a tiny bit until it fits snugly.


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## Bmwe39528i (9 mo ago)

Thanks! The only short cables I have are 1 male to 2 male rca. To run from one amp to the other. Can I plug the one male end into my speaker amp and connect the 2 male plugs on the other end to the sub amp, or does it have to be one for one, same colors?

I was wondering what's the point of actually having 6 channel output headunits, if you can split a single output into 6 outputs without loss of quality?


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