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Discussion Starter #1
when i use my aftermarket cd player i hear a high pitched whine that raises and lowers in pitch in direct correlation with the engine rev. someone said it could be "incorrect grounding" - i know nothing about sound systems and less about car electrical.

what should i do?

ALSO:

does anyone else find they get 90% less skip when mounting cd changers VERTICALLY? why are so many mounted horizontally??
 

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I find when I dont speed over potholes and not buy a POS it doesnt skip. :)

That whine is irritating as hell and can come from grounding or running a wire too close to another set of wires and the other wire causes "noise".
 

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Discussion Starter #3
i see you've experienced it :) how do i get rid of it cheif?
 

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I haven't had time to take my car in and let them mess with it, so I try to ignore it. Its usually not too bad.

One way is to run the wires on the opposite side of the car (assuming subs and/or amp are involved). If its just the HU, running the ground wire to another spot should help.
 

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The noise is called EMF bleed over. TO fix it:

1) Double check your ground connection on the head unit. Make sure you are grounded either to the harness (and that it's tight and no part of the wire is exposed).

2) If you have an amp double check that ground also, make sure you are grounding to the chasis where there is no paint. Also, run the RCA wires down one side of the car and the power wires down the other. This is a very common cause for the whine you get because the frequency bleeds from the power wire through to the RCA cables.

Make sure you're not using cheap RCA wires and/or other cables. Sheilding really helps in these cases.
 

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if you do have to cross wires do it at 90 degree angles. the propagation of electromagnetic waves are minimal at those angles
 

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If all fails, to isolate the ground loop you must run all aurio grounds directly to the batery.

Hope this helps.

tw
 

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Discussion Starter #8
thanks a lot gents. very much appreciated. will try asap. where the hell do i find the ground :)
 

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(i agree with everyone else about the EMF bleed, however i will add a suggestion to check just to cover all basis)
check the modulator for the CD player and see if you have a good solid frequency, sometimes the FM modulators pick up the voltage fields created by whatever (alternator, close power wire etc etc) and boosts the frequency of the station that is preselected.

btw- moving to electronic forum
 
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