Trying to kill the whine...

[rtscout]

I found the source of all my noise is in my RCA cables running to the (first) amp, an Infinity 7541a. I also found that if a get a small jumper wire to connect the two outer jackets of the RCA connectors at the amp input, thereby making a common ground, all the noise is eliminated. Is there some sort of device that can I can use as a permanent solution? I've also seen RCA's with a separate ground wire at the end... is that what this wire is for? Though I'd hate to replace on otherwise good set of cables.

Click to read more...

 

[disturbedfuel15 10+ year member]

You're not running your RCAs down the same side of the car as your amp power wire are you?

 

[rtscout]

Nope. The RCA's don't ever get near any power wires. I also have an MTX 4240 hooked in; I have both amps grounded together under one bolt (both ground wires are less than 12" and the ground is to the body and clean) - I've read that this is the preferred method, but I've also read that they should have separate grounds...?? I suspect it may be the HU's ground... and I've read that this ground should actually be extended all the way to the amp's grounds to ensure they are all at the same potential, which goes against the "shortest ground" rule. Lot of conflicting stuff out there.

 

[Big Dee 10+ year member]

RCA's with a separate ground wire at the end... is that what this wire is for?

That's for the remote turn on wire, not a ground.

 

[disturbedfuel15 10+ year member]

This should help ya //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

https://myeporia.eporia.com/resources/company_38/tech%20note%201002.pdf

 

[rtscout]

Great troubleshooter d.f.15 - thanks! (Big Dee... my reference for the HU ground wire installation: http://www.crutchfield.com/S-TxQkEwbSQoY/tech/kb348.html where they talk about ground loop).

 

[helotaxi 5,000+ posts]

You're not running your RCAs down the same side of the car as your amp power wire are you?

That doesn't matter.

What HU do you have?

 

[AJ²06 5,000+ posts]

That doesn't matter.
What HU do you have?

//content.invisioncic.com/y282845/emoticons/word.gif.64b12e39f936af3b4fff38a1c0bd0244.gif

 

[smd4life 5,000+ posts]

You're not running your RCAs down the same side of the car as your amp power wire are you?

the same power thats running through your power wire is running through the intire car

 

[reneeb7363 10+ year member]

WHAT!!!!??? //content.invisioncic.com/y282845/emoticons/eyebrow.gif.fe2c18d8720fe8c7eaed347b21ea05a5.gif

have ya never heard of RF energy????... by nature, DC is terrible about RF noise. If your signal and power wires are not HEAVILY SHIELDED you can, and in most cases WILL get a "whine" from the electrical system, if they are run parallel to eachother. (usually a poorley grounded alternator, charging system, or regulator or from having multiple grounding points in a system with multiple components; ie: a ground loop problem).

It is long known you should keep your signal from power in "longer" runs (front to back of trunk). If you MUST cross they should only do so at 90 degree angle of eachother.

 

[rtscout]

That doesn't matter.
What HU do you have?

An Aiwa CDC-X504MP... not a very good HU, but I don't want to go out and spend another couple of hundred bucks.

 

[helotaxi 5,000+ posts]

WHAT!!!!??? //content.invisioncic.com/y282845/emoticons/eyebrow.gif.fe2c18d8720fe8c7eaed347b21ea05a5.gif
have ya never heard of RF energy????...

Yes, I'm quite familiar with it.

by nature, DC is terrible about RF noise.

How? RF is radio frequency. RF ranges from high kHz into the MHz. DC is 0Hz.

If your signal and power wires are not HEAVILY SHIELDED you can, and in most cases WILL get a "whine" from the electrical system, if they are run parallel to eachother.

Really? Mine are run right next to each other and my system is SILENT.

(usually a poorley grounded alternator, charging system, or regulator or from having multiple grounding points in a system with multiple components; ie: a ground loop problem).

Ahhh, now you're getting somewhere. But this has nothing to do with RF or radiated noise or running your power wire and signal wire next to each other. A ground loop is caused by a bad ground on one or more components and is the source of 99% of system noise. Usually is is symptom of a difference in ground potential between the source unit and the amp.

It is long known you should keep your signal from power in "longer" runs (front to back of trunk). If you MUST cross they should only do so at 90 degree angle of eachother.

"Long known" doesn't mean squat excwpt that it's been wrong for a long time.

 

[Big Dee 10+ year member]

"Long known" doesn't mean squat excwpt that it's been wrong for a long time.

Amen to that. The earth was "long known" to be flat, and way to drop some knowledge.

 

[disturbedfuel15 10+ year member]

All you guys keep saying it doesn't matter, but when I had my first system, and I ran my RCAs and power wire right next to eachother, I was complaining about system whine. I talked to the audio installer's over there at Circuit City, and he said the first thing to try is to seperate the RCAs from the power wire. As soon as I ran them down opposite sides, the whining stopped //content.invisioncic.com/y282845/emoticons/eyebrow.gif.fe2c18d8720fe8c7eaed347b21ea05a5.gif Just a coincidence? I think not. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[helotaxi 5,000+ posts]

Just a coincidence? I think not. //content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

I think so.