Problems with an installation

cindy100

Hi again! Quick question (I hope) about an installation done on my car. I have had to take it back twice, one reason being there is a high pitched whining sound that was not there when I originally took the car in. Sorry, but I can’t think of another way to describe it. As I was driving home last night, I could still hear the noise which to me is very annoying and unacceptable. The first time this happened, I called the dealer and he referred to it as engine noise (I think, just can’t remember) and said it should be easily fixed. The installers said it was no problem to fix but it is still there. Any ideas what is causing this? I had new everything installed in my other car and did not have this problem. There is also a low hissing sound in addition to the whine; both noises are there even when the stereo is turned off.

I hope this made sense and someone can tell me what might be causing this. Thanks in advance for your help, again!

Cindy

exalted512

its called engine whine. Its electrical interference coming through your wiring. Most of the time the culprit is a poor ground or poorly shielded RCAs
-Cody

henee2

http://www.polkaudio.com/forums/showthread.php?t=46820

here the issue is explained by Mac Leod.

Btw. How do you like your momos now? I read that you were disappointed a bit Did they break in yet?

cindy100

Cody & henee2,

On the engine whine... going by what you said and the post by Mac Leod, shouldn't they be able to fix it or am I just being too picky? Since the noise was not there until they messed with it, would I be correct in assuming it's wiring they put in?

As for liking the speakers, they do sound a little better and I am going to give it a little more time as was suggested.

I have no idea what is in my other car; it has been so long since it was put in and I suppose I'm used to the way it sounds. Although I know they will make it right, I'm tired of messing with it but I also know I'm not going to be happy until it's fixed.

Thanks again,

Cindy

exalted512

Yes, they should fix it for you. Having noise in your system is unacceptable. You should be able to have the volume at 0, have your car in park and neutral and rev up your engine and hear absolutely nothing from the speakers.

What RCAs do you have? If theyre a really cheap kind, you might have to pay for new and better RCAs, but they certainly shouldnt have let it leave if it had noise. If I was to let a car go at our shop that had a noise problem, Id get my **** chewed out.
-Cody

Jstas

Engine whine can also come in through a poorly grounded antenna. Most antennas I have encountered in cars are poorly grounded to begin with. For some reason, Japanese cars tend to be the biggest offenders. Don't know why, it may be because of materials used or maybe thinner/less dense materials used. It may just be shoddy antennas too. Who knows.

How do you solve it? It can be hard. Something as simple as a ground loop isolator available at almost any parts store will usually fix it. Sometimes soldering a ground wire to the underside of the antenna mount and then using a lock washer and nut/bolt to secure it to a more solid body ground solves it too.

My most extreme solution was to leave the crappy motorized antenna in an Acura and I took a one-piece aerial antenna and secured inside the passenger side front fender with zip ties. I disconnected the motorized antenna and connected the new one to the radio. Reception was no worse than it was before but the whining stopped. That was the goal, to stop the whining.

Another source of whining is a tape deck. If you have one. Unfortunatly, there is little one can do to stop that. It's not a grounding problem, it's the tape head picking up the em field generated by the engine. About the only thing you can do is make sure your battery is grounded properly and check any engine ground straps for corrosion or damange and replace if necessary.


Also, your radio power and turn-on leads plus the ground in the wiring harness of the car itself could be bad. Wiring harnesses are not always the best way to go and previously, I have pulled ground and power wires for the head unit out of the harness and run my own power and ground wires to the head unit to solve whining and clicking problems.


You will get the whine mostly from high voltage sources. A turn-on/switchable lead or other signal lead like RCA or antenna will likely not cause a problem unless they are not grounded properly. Power leads will pick up noise. Most power leads are between 11.5 and 14.5 volts and if the car's electrical system is running in the same voltage range and pumping out scads of unconditioned power even slightly out of phase, it can cause serious whine. I've even seen power problems generate so much EM energy that they can move the speakers without the stereo power being on. However, speaker wires are usually not a source of noise because the power running through them is backed by ample power and is already conditioned. Plus, the signal frequency and strength is so variable that it is unlikely that a harmonic could be picked up and manifest itself in relentless EM noise.

The other place that noise can come from is a power lead bleeding over to a signal lead. Since the power lead has such a high energy level compared to the low voltage signal lead, it's EM field stomps all over the signal lead and forces noise into the system. It doesn't have to be stereo power to do it either. Something as simple as a signal lead running underneath a power seat motor could do it too.

The only really proven way to fix these problems is trace every wire, reroute where necessary and ensure that all grounds are properly contacted to something that can mimic an earth ground. In other words, for a ground to work, the ground point must have a mass larger than the power circuit can completely energize. This mimics an earth ground because there is no man made power source on earth capable of charging the earth as a whole. So the best place to make grounds are on the car's frame or on body panels with direct contacts to frames. In many newer cars, certain body panels are isolated from the frame to reduce vibration, road noise and improve fit/finish. Those body panels would not be an ideal grounding point. One other good way to minimize noise is, if it is absolutly necessary to run a power wire near a signal wire then cross the perpendicularly so that the fields of each wire are at polar opposites and any interference is more likely to cancel itself out.

cindy100

Hi! Just wanted to let you know I finally got the problems fixed in my car and couldn’t be happier with the sound, for now! I am already wishing I had gone with the other Polk speakers but I always do that any time I buy something like this. The engine whine is completely gone and I feel the speakers have broken in.

Thanks to everyone for all your help and suggestions; I would have been lost and certainly didn’t want to walk in the store not knowing anything. I appreciate everything!

Cindy

Jstas

What did the problem end up being?

black magic

does this whining noise come from the speakers or the engine?

brettw22

Is it possible for engine whine to be created by putting in aftermarket headlight bulbs?

black magic

brettw22 wrote:

Is it possible for engine whine to be created by putting in aftermarket headlight bulbs?

I have after market bulbs so do a million other people i know, and there's no whining. I don't know, it might be possible but i don't think it ever happens.

MacLeod

Yes it is possible.

An easy way to check if they are the culprit is to go pull the negative lead to them both (if you can get to it) and see if the whine goes away. If it does then you know.

The first thing Id do to remedy it would be to find a better ground location for them.

Joelsbass

Ground is probably the most common culprit, followed by RCA's being too close to a power source...

black magic

i noticed right after i installed my first sub, there was a whine, but it seems to have disappeared. I don't know what happened, but i'm not gonna complain either.