Wire shielding?

[Frankensuby 10+ year member]

Hey guys, I'm having an issue. I'm cramping all of my wiring for 2 amps, 4 speakers and a sub in one spot. It is resulting in a very small amount of power wire feed into the signal. AKA alternator whine. I know it is not a ground issue.

So is there any material I could use in order to separate and protect my signal cables from the close power cable? Maybe a form of wrap?

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[Boulderguy 10+ year member]

tin foil, grounded on either end. Wrap in electrical tape to hide the ugly factor.

 

[Wonger 10+ year member]

Lead somehow.

 

[Boulderguy 10+ year member]

Lead somehow.

Then cement, followed by titanium & hermetically sealed in thermowrap. //content.invisioncic.com/y282845/emoticons/biggrin.gif.d71a5d36fcbab170f2364c9f2e3946cb.gif

 

[n2audio 5,000+ posts]

shields don't block emi

they block high frequency RF, and that's not what's causing the noise.

I highly doubt the power wire is causing the noise anyway. My guess is there is some relatively high current pulsed dc (ignition?) flowing through the chassis near the signal wire.

 

[dleccord 5,000+ posts]

I usually electric loom the ends of the RCAs. Works good.

 

[helotaxi 5,000+ posts]

And you're sure it's not a grounding issue how? The signal ground isolation of the Audiobahn amp that you have on your speakers is probably the issue.

 

[Frankensuby 10+ year member]

I know it isn't the loop, because I've hammered out the isolation regarding grounds before. The ground checked out when i had the wires split apart, but as soon as I scrunched the wires together to install both amps and the sub, the noise came. It isn't very loud.

The only other thing I could think of is I rant he 8 gauge for the sub amp over the audiobahn, but not touching it, and it clear the audiobahn by about 1.5"-2".

That's the current setup. Even when I trade this ugly setup for my finished product, I will be running all of my wires with each other.

Do you think that overhanging power cable is radiating enough to get into the unshielded top of the amp?

 

[Thnking 10+ year member]

And you're sure it's not a grounding issue how?

X2.

What are your resistance readings.

Alternator whine is solely a grounding issue.

 

[davesmith]

The Only thing i can think is that you might need a ground loop for your RCA's if that doesnt work maybe you have to increase the resistance to the sub run your amps in parallel or in series muck about with different settings

 

[helotaxi 5,000+ posts]

What is the construction of your RCAs? Switch to a basic twisted pair design. The Stinger cables from the Hyper series (the blue ones) up and the Knu cables are twisted pair type. There are many others but these fall into the affordable range. This type cable is basically going to be immune to the type noise you might encounter in a car.

 

[Frankensuby 10+ year member]

The Scosches are twisted and shielded. I'm going to play with this tomorrow, but I'm fairly certain that it is because I have the 8 gauge close to the top of the Audiobahn.

And I got the same whine noise when my amp came loose and sat ontop of the distribution block(inbetween box and amps) before I put the mono on top, so it isn't always ground loop, or atleast not always ground cable loop.

I'll post an update tomorrow.

 

[Thnking 10+ year member]

The Scosches are twisted and shielded. I'm going to play with this tomorrow, but I'm fairly certain that it is because I have the 8 gauge close to the top of the Audiobahn.
And I got the same whine noise when my amp came loose and sat ontop of the distribution block(inbetween box and amps) before I put the mono on top, so it isn't always ground loop, or atleast not always ground cable loop.

I'll post an update tomorrow.

Alternator whine is always because of a ground loop. There's no arguing it.

Twisted and shielding isn't contributing or reducing anything.

The field flux generated by DC carrying copper/silver/etc. wire is so small, it's not inducing anything into the wiring.

 

[Patri0t]

shields don't block emi

they block high frequency RF, and that's not what's causing the noise.

I highly doubt the power wire is causing the noise anyway. My guess is there is some relatively high current pulsed dc (ignition?) flowing through the chassis near the signal wire.

I know this is an old thread but this is bad info and needs corrected.
"High Frequency RF" is redundant.
While any electrical field can cause electric and/or magnetic wave generation, generally only rf is powerful enough to propagate to another conductor over distances over a couple millimeters with regular insulation.
A solid metal covering will create a magnetic eddy canceling effect and grounding it will cause a full Faraday effect through both the inability to be penetrated by any length frequencies and capacitive coupling grounding out any magnetically induced currents. This isn't really a problem with steady dc current, but frequency noise from the alternator & other car electronics can pose problems.
Still nothing that a solid grounded shield can't overcome.
Cheers