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Discussion Starter · #1 ·
First a little info:
2000 Jetta 1.8T
HU - Eclipse 5441
Amp - Orion 500.4 (65x4w rms)
Speakers - MB Quart Components
Sub - (1) JL 10w3
The noise is a constant, scratchy "weeeeeeeeee" and it also matches revs. My subs make no noise. The strange thing about it is that the noise comes and goes. It usually comes on when I gas it. When I turn off the car, the noise goes away. When the car is in ACC mode, there is a scratchy noise coming from the tweeters when I step on the accelerator.
I brought it back to the shop that installed it and they set the gains low and threw in a ground loop isolator. The noise went away temporarily and eventually came back. The second time I brought it back all they did was set the gains low (although the gains weren't high in the first place). It magically went away, then came back today. This is seriuosly bugging me out, anyone knows what's wrong?
 

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Re: Ground noise driving me crazy - Please help (specialk_lsi)

Here's an easy question, did they run the RCA cables next to the power cable ?
DId they try a different grounding location
 

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Discussion Starter · #3 ·
Re: Ground noise driving me crazy - Please help (supertle)

i thought of that too, but wouldnt the noise be constant if that were the case?
 

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do u know where did they put ur xovers? cuz i had the same problem and it was the crossvoer next to some power cables.
 

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Re: (specialk_lsi)

same problem on my system. I was thining partly due to my plugs, but there probably is a bad ground somewhere.
 

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What you are describing is called a ground loop and the solution is so simple you'll want to cry: You need to ground ALL your car sound equipment to the same physical spot. Amps, crossovers, equalizers, AND head unit should all be grounded in the same place. Try running a (at least) 18 ga wire from your headunit to where your amp is grounded, and disconnect the ground that's connected to the HU. In 95% of the cases a proper grounding of all your equipment will solve all of those annoying litttle noises.
 

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Discussion Starter · #9 ·
Re: (cheebs)

i wonder what the shop will say if i tell them that, haha.
currently it's not making any noise (hope i'm not jinxing it). but thanks for the info, i'll check that if it comes back.
 

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Re: (specialk_lsi)

Just an fyi i had a similar problem noise was making me nuts. Nothing worked, ripped the wires out re wired again and again. Untill I started to look else where and took it to my mechanic and he told me that one of my spark plug wires was bad and was arching he changed it and BANG the noise was gone so sometimes it is not the obvious. Hope you got it fixed.
 

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Re: (andru1313)

Quote »
Untill I started to look else where and took it to my mechanic and he told me that one of my spark plug wires was bad

Your car has spark plug wires?!
 

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Re: Ground noise driving me crazy - Please help (specialk_lsi)

You would think a professional installation shop would be able to install audio equipment. Have them really fix it and not just cover up the problem with a ground-loop isolator.
 

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Re: (genixia)

Quote, originally posted by genixia »

Your car has spark plug wires?!

I'm a fan of spark plug wires and always try to have at least a few in my car.
 

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Discussion Starter · #15 ·
Re: (andru1313)

i'm taking it back to the shop today, asking them to CHECK THE GODDAMN GROUNDS!!! instead of saying hmm, your gains are too high (2/5ths the way up ).
wish me luck!!
 

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Discussion Starter · #16 ·
Re: (specialk_lsi)

ok.....i want some opinions, fact or total b*ll****....
when i brought it back, the guy said, i think you need a new amp. i told him that it worked in my other car just fine and he said, "your car is not grounded good. if you put that amp in a dodge stratus, the noise will be even louder. different cars are like that." personally i think it's total bs. i bet they're not even gonna look at it.
 

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BS BS BS BS BS if it works in one car it MUST work in another!!!
That just sounds like some dumass salesperson trying to get you to plunk down more cash for a new amp. Get him to put in a grounding block, and to ground all your gear to that block (which in turn is connected to the chassis with a hefty 8 or 4 ga cable). I'm willing to bet that will solve your problems.
Dude I've been doing my own installs for over 20 years and learned about ground loops the hard way.
Here's a diagram of the power part of my system to illustrate, as you can see ALL the gear is grounded at one point:


Modified by cheebs at 11:06 PM 7-11-2003


Modified by cheebs at 11:07 PM 7-11-2003
 

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Re: (andru1313)

Quote, originally posted by andru1313 »
I guess my car is special...... Lucky Me do you have spark plug wire envy?

No, I got lucky with my coilpacks.
I didn't realise that the VR6 still had a monolithic coil and wires.

Quote, originally posted by Ratamahatt »
I'm a fan of spark plug wires and always try to have at least a few in my car.

Fair enough. A '90 Corrado wouldn't run too well without spark plug wires. Some 2001/2002 1.8T drivers became 'fans' of their coilpacks in a similar way...they wouldn't leave home without spares!
 

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Re: (genixia)

I had a similar problem... it turned out to be noise coupling into the RCA cables... I did have good quality ones... but I had a 4 ch amp,with two stereo RCA cables... as soon as I connected one ground, or + of the second RCA cable, the alternator whine started!
It is because you create a loop area between the two cables...
Only way to slove the problem, is to have a RCA lead with 4 positive (inner) conductors, and a single Ground (shield) around the outside of the 4 positives...

Or use a ground loop isolator... its basically just a transformer (or impedance matching circuit) I don't know why people are against them... cause I couldn't hear any difference at all... except that the whine was gone!

I suspect you have the same problem... a 4ch amp, with common grounds on all the channels!
Try what I said, disconnect the one pair of RCAs, and I'm sure the sound will dissapear...
So look if you can find a 4ch RCA cable like I described, or just put a ground loop isolator in the line goign to one of the stereo channel pairs.
Good luck!
PM me if you still have problems
 
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