# power wire separate from speaker wire



## baker001 (Nov 5, 2006)

Is it necessary to run speaker wire to the back of the car separate from the power wire? I have a 4ga. power wire and 3 pair of rca's plus remote wire and speaker wire. I would like to run them all in the same groove.


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## SteveLPfreak (Sep 26, 2005)

As a rule of thumb, signal cables (RCAs, speaker wire is not usually affected) should be run perpendicular to power cables, not parallel. However, you may be able to run them down the same groove together with no ill effects. Try it and see.


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## pupsi (Nov 22, 2006)

some people get alt whine and some dont, like above, just try it and see dude


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## yermolovd (Oct 10, 2005)

I get the alt whine even with signal and power wires on different sides haha.
Just try it man, never hurts.


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## Thoraudio (Aug 9, 2005)

power wire + signal wire is not a problem.


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## solacedagony (May 18, 2006)

Didn't someone do an RC challenge type thing saying that power wire can't cause audible noise or something? Maybe I'm way off.


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## Relax (Apr 24, 2006)

Your power wire is DC therefore has no change(well small ripples) in the electrical field = no noise (AC) can be introduced.

Speaker wire near RCAs would hurt- but only if you are sending rediculous amounts of power through them, i.e. 1000 watts. Or if you are in a home environment where an AC power cord comes near your signal wires.


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## legend94 (Mar 15, 2006)

I have never had any problems with running different wires together. I have so many I use the left, right, and middle for my wires. I run the rcas down the middle if possible to get the shortest rca length.


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## solacedagony (May 18, 2006)

Relax said:


> Your power wire is DC therefore has no change(well small ripples) in the electrical field = no noise (AC) can be introduced.
> 
> Speaker wire near RCAs would hurt- but only if you are sending rediculous amounts of power through them, i.e. 1000 watts. Or if you are in a home environment where an AC power cord comes near your signal wires.


So only AC can introduce noise?
I guess we should get a definitive answer on WHY noise is introduced.  I know nothing of electronics.


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## chad (Jun 30, 2005)

Because DC does not have an expanding and contracting feild. Gotta have that to have induction.

Chad


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## baker001 (Nov 5, 2006)

thanks for the quick responses.


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## tdgesq (Apr 16, 2006)

So am I the only one who has experienced alternator whine due to running power wire along with rcas? That figures. Here's what sucks, when you have whine coming from two different sources. I had a ground loop and noise coming through my rcas. I fixed the ground loop (used muting plugs and all) and then figured out noise was coming through my rcas as well. Used different interconnect, still had noise. But, once I picked up the rca cable away from the power cable, the noise went away. You could actually hear the noise get fainter and fainter as you slowly moved the interconnect away. Once you started moving it back, noise got stronger. I don't have a technical background, but I wouldn't run them together. Then again, I believe that evil spirits inhabit my system.


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## Thoraudio (Aug 9, 2005)

tdgesq said:


> So am I the only one who has experienced alternator whine due to running power wire along with rcas? That figures. Here's what sucks, when you have whine coming from two different sources. I had a ground loop and noise coming through my rcas. I fixed the ground loop (used muting plugs and all) and then figured out noise was coming through my rcas as well. Used different interconnect, still had noise. But, once I picked up the rca cable away from the power cable, the noise went away. You could actually hear the noise get fainter and fainter as you slowly moved the interconnect away. Once you started moving it back, noise got stronger. I don't have a technical background, but I wouldn't run them together. Then again, I believe that evil spirits inhabit my system.


I'll bet a dollar, if you had left the RCA's and moved the power wire, the noise would have stayed.


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## B&K (Sep 20, 2005)

I'm with Thor on that one, I have never seen it make a difference.


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## tdgesq (Apr 16, 2006)

We'll find out this weekend since I have to install my sub amp anyway. I hope you're right because I would love to run my rcas down that same path.


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## Relax (Apr 24, 2006)

chad said:


> Because DC does not have an expanding and contracting feild. Gotta have that to have induction.
> 
> Chad


SLightly more eloquent then I said. lol

But exactly right- In order for noise to be introduced into a wire- a changing electrical field must be present. A DC power wire has very minimal changes in its field, therefore introducing little if any noise.

Speaker wires and AC power have rapidly changing fields surrounding them which introduce noise into other wires nearby. Modern shielding and wire wrap reduce the effects dramatically though.


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## MarkZ (Dec 5, 2005)

x100 -- it makes little difference.

Well, except for the guy who told me my 4 gauge wire acted as an antenna and blew my rear interior module through induction.


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## solacedagony (May 18, 2006)

MarkZ said:


> x100 -- it makes little difference.
> 
> Well, except for the guy who told me my 4 gauge wire acted as an antenna and blew my rear interior module through induction.


That guy knows more than all of us


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## Ianaconi (Nov 11, 2006)

Well guys..

Here in Brazil we have a different concept. We usually run interconnect and speaker wire away from the power wire.

I have installed a few systems, and also many installers here with plenty of experience in IASCA,etc always recommends that.

I know some people can prove with technical data/etc that it doesn't make a difference. But I have seen alt whine stop after moving just the power wire. hehe 

Maybe it only works here in the south hemisphere haha


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## chad (Jun 30, 2005)

I've had WAY more problems having speaker and signal together, but not in car audio 

Chad


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## tdgesq (Apr 16, 2006)

I asked one of my EE friends how likely it would be that in my setup the DC power cable could be introducing noise into the low level rcas. Here's what he said:

_The short answer is that there is no such thing as DC. The phrase "direct
current" implies to a lot of people that the voltage and/or current of the
power isn't changing like it is in AC. But in reality, if you have a device
pulling current from a battery, it can pull a changing amount of current. A
motor is a good example: it'll pull a wildly changing current from a
battery. The voltage to the fan may not change much but the current can go
from low milliamps to spikes of amps. Changing currents like this lead to
changing magnetic fields around the cables. If you place a second, low
voltage/current cable near this one with the changing currents, those
changing magnetic fields will induce a current in the second cable. (If you
didn't have a changing magnetic field, you'd be ok. Its the change in the
field that causes problems. Thats why if it were truly a DC system --
meaning that voltage and current never changed -- you'd be ok. But thats
never true.)

The problem of noise from a power line being induced into a signal line is
very common. It depends on five (or more) factors: the current change in the
power cable, the signal levels in the signal cable, the distance between
them, the shielding of the cables and the configuration of the actual signal
cable. I can't really get into how each of these impacts the amount of
interference (induction) between the cables but here are some tips that we
use:

1) Never run a low signal-level cable near a power cable. If you have to run
a signal cable near power, amplify the signal first.
2) If you have to cross a signal cable with a power cable, cross them at
right angles to each other. Electromagnetic (EMAG) fields don't interfere at
right angles (thats just how the physics works.)
3) It is VERY hard to shield signal cables from EMAG so don't try. Placing
steel or something between the cables could help but it could also
exacerbate the issue by providing a path for the EMAG field to pass EASIER
to the other side.
4) By placing ferrite beads in the power cables, you can slow down the
change in current in the power cables and that will reduce the magnetic
induction (or at least move the frequency of the interference lower where
you might not notice it.) But if the currents are too strong, you may need a
MASSIVE ferrite.

By the way, if the amp is a Class D or some other type of switching amp, these
amplifiers pull massive changing currents as part of the switching process.
I think only a Class A or AB would (maybe) pull a steady enough current to
not cause interference._

Like I said, I will be testing it this weekend. Will let you know how it turns out.


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## Relax (Apr 24, 2006)

By all means- if you cna prevent the power and signal wire from being next to each other- it is best.

However, if you can't avoid it don't sweat it. A changin DC field can introduce some noise- but its nowhere near that of an AC source, and DC current doesn't change as much as the guy quoted above would ahve you believe.


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## chad (Jun 30, 2005)

Also remember that DC can be pulsed, at any frequency, as long as it's going one direction it's still DC. Pulsed DC can and will cause induction, that's how the PWM power supply works in your amplifier.

As for your hints.... #1 states amplification, It can be a 1KV line and still be suseptable to induction. It's the CURRENT on the line that matters. #4 Ferrites work above certain freqs. Usually above that of alternator whine. They are great for quenching RF noise from spark emitters like motor brushes in fuel pumps and fans but not alternator whine which has it's fundamental frequency well within hearing range. To quench alternator whine you would need a torrid... And a big one at that.

Not only does a clad D amp take it's power in gulps but thay make a bunch of switching noise inthe RF arena due to switching harmonics. Most are well filtered though.

Honestly I think you are on the right track, the best method is trial and error. What if you run your signal cable down the other side and it's nestled nicely with, say, the fuel pump line, which may just make MORE noise?

Chad


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## MarkZ (Dec 5, 2005)

tdgesq said:


> I asked one of my EE friends how likely it would be that in my setup the DC power cable could be introducing noise into the low level rcas. Here's what he said:
> 
> _The short answer is that there is no such thing as DC. The phrase "direct
> current" implies to a lot of people that the voltage and/or current of the
> ...



That's a great post. Everything he said is right on the money. However, the question isn't about whether inductive noise occurs -- it's about how much of it occurs. If the induction is buried in other sources of noise, then it's not going to matter. And the fact is that in most installations (I won't say all, because I haven't done every installation on the planet ), it'll never produce an audible effect.


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## cvjoint (Mar 10, 2006)

I have issues with the PPI x3 crossover. This thing needs to have wires going out of it very clean, I actually put a bunch of electrical tape around the power, ground and remote turn on for a few inches before they go out.

I had issues with rcas but usually only where I use couplers to extend the wire or split it, electrical tape around those too.

I never thought about not putting toghether speaker wire and signal cable hmmm that might solve my current whine problem....thanks


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## Abmolech (Nov 2, 2006)

It may beg the question of running your RCA's along the return wire.... chassis.


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## DonutHands (Jan 27, 2006)

i am going to have to run some wires together. what is the least harmfull combo

power
rca
speaker

the plan now is to run the rca and speaker wire together and the power on its own.

but if it does not matter i would like most to run power on the left rcas on the right and left speaker wire on the left and right on the right.


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