JVC head unit alternator noise trouble

[xclusivecar]

OK--

Replaced the becker with a JVC HD radio receiver. Bought thru Crutchfield using their wiring harness and PAC oem-2 adapter to retain the oem amp and speakers. Install went fairly well with the exception that I now have the dreaded high pitch whirring noise in all speakers. This sound is RPM dependant. After checking all grounds and re-grounding the noise still exists. After a call to Crutchfield and the service tech making me splice/re-splice different wires he determined it was a power issue and not a grounding issue. I was told there was nothing I could do to get rid of the whirring noise.

Anyone who has replaced their receiver had this problem and had a solution??? I guess I would try to splice in one of those noise cancellation devices..but this seems more like a band-aid than a fix.

Sorry so long...BTW--I LOVE the HD signal in Chicago!!!

Thanks!

[JFERR]

Your problem is a common one. Anytime you replace a headunit in a car and use an adampter to plug into the existing OEM amp, you get alternator whine. I'm not an installer, but every installer I spoke to (5), said the same thing. You must also replace the amp or you will get alternator whine.

In the past, when I've replaced head unit's myself, I got alternator whine.

I know it's expensive, but put back the Becker, return the new head unit to Crutchfield and have a professional install a new head unit & amp. At least this way, you don't pay him/her until the sound is clean.

Good Luck

[DAAM421]

NO NOISE HERE. i replaced my head unit with an alpine unit,5 channel amp, alpine door and dash speakers along with an alpine 10inch sub...1 farad cap....sounds clear and no engine whine.....

Loser. Your a load of help. I replaced mine the exact same way and im not getting the whine. Mines a 99 BTW

[DAAM421]

WE UNDERSTAND!!!! YOUR A DICK...OK...WE KNOW YOU DON'T LIKE ME, BECAUSE ??? i bashed your painted tail lights,,,,lets be civil......you dont have to reply that im a loser and im no help...what does your reply say in helping this guy,nothing!!!!...i have no problem with you,just the **************** job you did and the safty issue. get over it and lets help this guy out

When I say your a loser, I am not implying anything other than what you said in this thread. What I said was that I did the same thing as him except I have a different year car and that its not normal if his car does it. I don't care about the lights, so what? I think your some 13 year old kid who can't even drive and wants to annoy people because you have a bad life. You certainly seem to have the grammar and education of a 13 year old. Why are you even on the forum if you "have already done everything" (including your list of "mods" and stereo stuff), won't help anyone, or post anything original? You need an attitude adjustment that your father never gave you. Why don't you try and figure out your problems instead of being unhelpful and a burden on this forum.

[DAAM421]

BOO HOO my dad hates me you can't get a rise out of me.trust me

[RandallNeighbour]

Xclusivecar, you could simply buy a noise eliminator and put it on the power lead going into your head unit. Crutchfield and Radio Shack both sell them.

I had my Alpine head unit installed by a professional and they reused my stock amp and speakers and that alone made a world of difference. The new head unit cleaned up the sound so well beyond the nasty original becker unit that I'd never go back to a factory-look becker unit.

[xclusivecar]

Originally Posted by RandallNeighbour

Xclusivecar, you could simply buy a noise eliminator and put it on the power lead going into your head unit. Crutchfield and Radio Shack both sell them.

I had my Alpine head unit installed by a professional and they reused my stock amp and speakers and that alone made a world of difference. The new head unit cleaned up the sound so well beyond the nasty original becker unit that I'd never go back to a factory-look becker unit.

RandallNeighbor--

You win!!!!! I installed a noise filter and now the noise is DRAMATICALLY reduced. This is how it should sound! The funny thing is that I talked to Crutchfield, an installer in my neighborhood, and asked online and EVERYBODY said I was basically screwed. I would either have to live with it or put the Becker back in. Even Crutchfield told me to return my car to stock after running through many tests with me. They said a noise filter would not work. Oh well...20 bucks for the filter and I decided to give it a try...and as you stated my man...IT WORKED!!! Thank you!

[MNBoxster]

Hi,

A line Noise Eliminator is just a Band-Aid and reduces the noise but doesn't eliminate it. It also has an adverse effect on the sound, though undetectable by some.

I suspect the issue is with your Alternator. Either it's not properly grounded, or one of the 3 Diodes is shot. Do a load test on the Alternator to be sure, but I bet this is the source of your problem. Hope this helps...

Happy Motoring!... Jim'99

[JackG]

Originally Posted by MNBoxster

Hi,

A line Noise Eliminator is just a Band-Aid and reduces the noise but doesn't eliminate it. It also has an adverse effect on the sound, though undetectable by some. Happy Motoring!... Jim'99

The filter doesn't eliminate the source of the noise, but it does reduce or eliminate it from the power supplied on the load side of the filter. All head units have some basic filtering in their power inputs, the noise eliminator (filter) is just a filter targeted to that characteristic alternator "whine".

The "adverse affect on sound" that MN alludes to can only be from the limitation on dynamic current swings that music will require. One of the main components of the filter is likely a large choke, (coil, inductor) that all the DC current must flow through. One of the main electrical properties of inductors is that once current is flowing through them, they resist any change in that current flow. That would limit the dynamic range of a amplifier that is attempting to drive speakers, as it takes that 12v current flow to produce the power that drives the speakers.

In xclusivecar's case, he has no worries. He retained the OEM amplifier, and since the noise filter wasn't installed in its power lead, the amplifier still has a direct source of current supply. The head unit isn't requiring any appreciable dynamic current, since the low level audio signal paths and the outputs to the amp only require a few hundred milli-amps of current (far less than 1/2 amp).

Obviously, eliminating the source of the noise is best. Until then xclusive, enjoy the new tunes!

[MNBoxster]

Originally Posted by JackG

The filter doesn't eliminate the source of the noise, but it does reduce or eliminate it from the power supplied on the load side of the filter... Obviously, eliminating the source of the noise is best. Until then xclusive, enjoy the new tunes!...

Jack,

Great explanation! You must be a double 'E'?...

Happy Motoring!... Jim'99

[xclusivecar]

Thanks for the info JackG and MNBoxster! The noise is still there but *very,very* hard to detect now...Many people have brought up the bad diodes diagnoses but since the noise is now gone should I still have the alternator tested? Maybe its on its way out.?.?. and needs replacement? Again...thanks to all....funny how Crutchfields' techs advised me to just deal with it...or return the unit.

[MNBoxster]

Originally Posted by xclusivecar

Thanks for the info JackG and MNBoxster! The noise is still there but *very,very* hard to detect now...Many people have brought up the bad diodes diagnoses but since the noise is now gone should I still have the alternator tested? Maybe its on its way out.?.?. and needs replacement? Again...thanks to all....funny how Crutchfields' techs advised me to just deal with it...or return the unit.

Hi,

The noise is now undetectable, but the ear is a funny thing. I had a similar issue once, and each week, the sound which had initially been undetectable became more and more noticeable.

So far as the alternator, there are 3 pairs of phase (or output) diodes and 3 Field Diodes which convert the AC current produced to DC current which the car can use. They're actually pretty fragile. They usually fail individually, reducing the current output by ⅓ for each diode which has failed and also a potential cause of the noise you hear.

Most people don't even recognize a failing alternator until 2 diodes fail leaving insufficient current production to recharge the battery and run the accessories. So, aside from excess noise in the Sound System, you may have a failing Alternator which will reduce the life of your battery with time as well. So, there's a two-fold benefit to getting it checked out.

There are lots of local Auto Electrical Shops which will rebuild an alternator usually for under $100. They can often even add additional windings allowing the Alternator to produce more current than before as well ...

Happy Motoring!... Jim'99

[JackG]

Originally Posted by MNBoxster

Jack,

Great explanation! You must be a double 'E'?...

Happy Motoring!... Jim'99

Now you've done it!! You called me an engineer. Your payback is coming...

[Sammy]

Originally Posted by JackG

Now you've done it!! You called me an engineer. Your payback is coming...

And what are you trying to infer about engineers (granted I'm not a gEEk)???

[RandallNeighbour]

Originally Posted by MNBoxster

A line Noise Eliminator is just a Band-Aid and reduces the noise but doesn't eliminate it. It also has an adverse effect on the sound, though undetectable by some.

This makes no common sense to me. The noise eliminator is put between the power line coming from the car and the head unit. It simply eliminates certain frequencies to pass through the power leads. It should have no bearing on what the head unit produces and sends to the speakers, but it does have a bearing on what the head unit does not transfer to the speakers.

[MNBoxster]

Originally Posted by RandallNeighbour

This makes no common sense to me. The noise eliminator is put between the power line coming from the car and the head unit. It simply eliminates certain frequencies to pass through the power leads. It should have no bearing on what the head unit produces and sends to the speakers, but it does have a bearing on what the head unit does not transfer to the speakers.

Hi,

Not exactly true. This type of noise can be signals which the power leads pick up and transmit (along with the power) to the Head Unit's circuitry. This can then be amplified. Noise filters block specific frequencies or a range, but often these stray signals fall outside the range of the filter and some still passes through.

With alternators, AC is produced and converted to DC current. But, some stray AC can still be present and cause the noise.

Another issue, as I stated, over weeks, the human ear can adjust and pick up this noise once again. In any event, the Lister will subconsciously be listening for it.

I say it's a Band-Aid in that it merely covers up the problem, when the cleanest sound will be had through eliminating it. As I said, I suspect theere's a Diode or two not up to snuff in the Alternator and this is where the noise emanates from. But, it also means that the Alternator is not 100% and may need attention anyway in short order which is why I recommend having it checked and killing both birds at once...

Happy Motoring!... Jim'99

[JackG]

Originally Posted by RandallNeighbour

This makes no common sense to me. The noise eliminator is put between the power line coming from the car and the head unit. It simply eliminates certain frequencies to pass through the power leads. It should have no bearing on what the head unit produces and sends to the speakers, but it does have a bearing on what the head unit does not transfer to the speakers.

Read my previous reply to this. The only effect the noise eliminator could possibly have is to restrict the current flow into the head unit. This, in turn, can effect the dynamic range of the power amplifiers driving the speakers (if the amplifier is indeed in the head unit itself, and not outboard).

When you go from a quiet to a loud passage in music, or play a big bass note, or have a sharp drum hit, the power sent to your speakers jumps from a small value to a large one. For example, it could jump from 0.1 watts to 40 watts. This power doesn't come free, so the amplifier gets it from drawing more current on it's 12 volt input side.

The noise eliminator limits how fast the amplifier can get the extra current it needs. In effect, the amplifier now sounds softer, or muddy. Depending on what type of music you listen to, how loud, how good you ears are, and how "picky" you are about your system, you may or may not hear this effect. With the built-in amp most head units have, you may not hear it anyway, as they are pretty limited in their power output to the speakers, and therefore their power input requirements are fairly small.

Clear as mud?

[RandallNeighbour]

Jim, I've had this noise in every single aftermarket audio system I have installed in cars when the alternator was working just fine or even brand new! To say that xclusivecar needs to have his alternator checked out because there's a little remaining whine is quite speculative and reaching if you ask me.

xclusivecar, if you're happy with your system, drive the car and crank up the tunes while you're at it. I certainly wouldn't spend any money to have an alternator checked out if your battery isn't weak... alternator noise is typical in high powered head units and amps and I always assume it will be there if I don't use a filter.

Jack, I see what you're saying... so what do the high end amp manufacturers do to eliminate the ever-present alternator whine without filtering that "chokes" down the power?