whys the ground wire so short?

[helotaxi 5,000+ posts]

Mine is 5 feet. But it's dual 1/0 guage...

It's only 5 feet between your battery and amps?

 

[XDrkmanX 10+ year member]

the longer the wire, the more the voltage drops
voltage drop = bad

I could be wrong but doesn't the ground wire have no voltage.

 

[yo0123yo 10+ year member]

so if i dont do competition shit at all then is it ok if my ground wire is like 4-5 feet? would i notice anything instead of if it was like 3 ft?

 

[XDrkmanX 10+ year member]

found this on another forum

Letter from JL

Here is the reply I received from JL Audio when I asked why the owner's manual reccommended a short ground to the chassis and the installer was referred otherwise;

Mike,

Thank you for your interest in JL Audio. In the owners manual, you are going to find a recommendation to have the ground as short as possible. This can be done with most vehicle and most audio amplifiers. You can run a ground wire back to the battery. This can be better then grounding to the chassis of a vehicle. As long as the ground wire is as large as the positive wire, there is no problem.

We have done some testing on all different vehicles. This test was to measure the resistance of frames and uni-body constructed vehicles. The best are the vehicles that have a true frame rail, like your Suburban. You want the ground wire from the amps to be mounted to the frame. You also want to upgrade the factory ground return wire. This runs from the negative side of the battery to the frame. Now the best results only equaled the same resistance as a 4awg wire. Uni-bodies are like an 8awg.

This installer made sure that the ground return of the amplifiers do have the least amount of resistance. This preventing any type of voltage choke.

There is no problem doing this. As long as it is done correct. In this case, I am assuming it was.

 

[yo0123yo 10+ year member]

sweet so it dont matter how long it is as long as its as big as the power

 

[helotaxi 5,000+ posts]

I could be wrong but doesn't the ground wire have no voltage.

Anywhere current flows and there is resistance (there is always some resistance) there has to be voltage. For the perfect ground, there would be zero voltage potential, i.e. zero resistance, but the only place you will really have that is the neg post of the battery.

The higher the resistance of the ground path of the amp, the more voltage is lost as heat between the amp and the battery/alt. If there is not a high current draw from the amp, this usually won't be enough of a drop to be of concern, however, in high power systems that are regularly cranked up and draw a lot of current, you must work to minimize the resistance of the ground path as well as the positive power wire. This is where large power cables and battery direct grounding comes into play.

 

[iamamp3pimp 5,000+ posts]

sweet so it dont matter how long it is as long as its as big as the power

shoud be a similar length to the power wire as well.

I am putting a batt in the back, so i wont have that problem.

 

[spudracer326 10+ year member]

so I could run my ground to the negative post of my batterey then???

 

[Mr. Opportunist 10+ year member]

mine went straight to my battery so idk 14ft give or take

 

[iamamp3pimp 5,000+ posts]

so I could run my ground to the negative post of my batterey then???

yes

 

[helotaxi 5,000+ posts]

shoud be a similar length to the power wire as well.
I am putting a batt in the back, so i wont have that problem.

If you are grounding the rear battery to the frame, you will still have the same problem with the car running as you would if you just had the battery up front. With the car running the point of zero potential (ground) is the case of the alternator and your amp ground is only as good as its connection to that point.

 

[iamamp3pimp 5,000+ posts]

so youre saying that i need to run 4 ga or w/e from the front to the back....twice?

 

[helotaxi 5,000+ posts]

To do it right? Yes.

 

[Rsx_03 10+ year member]

i though all you had to do is run 2 wires (+,-) from your alt to your battery in the back of the car