ground wire guage

[Benny212 10+ year member]

Right now I have 4 awg wire running from the battery to a dist block in the trunk, from there I have 4 awg running to my sub amp and 8 awg running to my front speakers amp. I'm gettin some bad alt whine. But is it ok to run different sized ground wire to the different amps? I have read that the resistance of the ground wires should be equal to get rid of alt whine, but I have seen other people run wires in the same way that I did without alt whine.

thanks

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[helotaxi 5,000+ posts]

Are they both grounded to the same point? Are the ground wires as short as possible? Is the ground point sanded to bare metal? Is the ground point a major piecs of sheetmetal on the car? If you can answer all of these questions yes, then the problem is likely with the ground on your headunit, not your amps. Try regrounding your headunit to a major piece of metal under the dash (not part of the dash but rather a spot on the firewall or such). As a last resort you can run a ground wire from the HU back to the spot that the amps are grounded.

 

[pavengmike6 10+ year member]

My first question would be are you getting wine through your subs or your mids and highs?

Alternator wine comes from a number of areas. It is usually the amplification of an outside electircal source being inputed into your amps. This will usually happen when you run your RCA's and speaker wire near your power wire. If you RCAS and speaker wire are run on the same side of the car, I would move them. I would have no less than 1 foot of distance between the power and the other wires.

Alt wine does also come from a problem with the amp not being able to get rid of the power it brings in (faulty ground). Yes you can run 2 different size ground wires, but it is not reccomended. Also the ristance will change when you stack 2 grounding points on the same ground area, making the amp not work as well as it should.

Did you use connectors for you grounds, or did you strip wire and wrap it around a bolt? IF you are goind to use 1 grounding point, you need to get a distro block to stop you from rasing the resistence of the ground.

If you did not use high quality wire (for your power) you will have a large electronic field around the power wire, and you will get a lot of feedback if other wires are near it.

 

[DBfan187 5,000+ posts]

get some wire here for a good price! http://www.caraudioforum.com/showthread.php?s=&threadid=180412 He's a good guy!//content.invisioncic.com/y282845/emoticons/wink.gif.608e3ea05f1a9f98611af0861652f8fb.gif

 

[helotaxi 5,000+ posts]

Alternator wine comes from a number of areas. It is usually the amplification of an outside electircal source being inputed into your amps. This will usually happen when you run your RCA's and speaker wire near your power wire. If you RCAS and speaker wire are run on the same side of the car, I would move them. I would have no less than 1 foot of distance between the power and the other wires.

The power wire is DC. If it is affecting your AC signal, then you have problems with your DC not being DC.

Alt wine does also come from a problem with the amp not being able to get rid of the power it brings in (faulty ground).

It can't bring it in if it can't get rid of it. It won't cause noise but it might keep the amp from making proper power or cause it to clip earlier than it would with a good supply of current.

Yes you can run 2 different size ground wires, but it is not reccomended. Also the ristance will change when you stack 2 grounding points on the same ground area, making the amp not work as well as it should.

As long as the wires are adequate for the amps they are grounding they are fine. Stacking two terminals won't hurt anything either. Terminals are generally tinned or plated copper and are better conductors than the sheet metal of the car. What a bad ground will do is cause a difference in ground potential between the HU and the amps. On inexpensive components the signal is not isolated from ground and the ground plane will try to equalize through the RCA. This is a ground loop and is the most common source of alt noise.

Did you use connectors for you grounds, or did you strip wire and wrap it around a bolt? IF you are goind to use 1 grounding point, you need to get a distro block to stop you from rasing the resistence of the ground.

A distro block looks nicer but is not really needed. Two terminals and a bolt will work fine.

If you did not use high quality wire (for your power) you will have a large electronic field around the power wire, and you will get a lot of feedback if other wires are near it.

Funny. I've never seen shielded power wire nor would I waste the fortune it would surely cost were it available. My Audiopipe 1/0 works just fine.

 

[pavengmike6 10+ year member]

Seeing I am not this good with the quote thing I will just say what is from the post before.

It does not matter if it is AC or DC. There is an electronic field around all wires. (that have power going through them) The field size can be different sizes based of the amount of power going through the wire, and the amount of sheilding on the wire. The wire that your stereo is using is AC, but that too can pick up a signal from your DC power wire if they are run to close to each other. YES HELO rubber is used as a shield, so you have seen sheilded power wire. I was not talking about the 100.00 a foot aircraft wire. Take a look at different wires, and you will see what I mean. The cheaper wire is cheaper for a number of reasons. 1st is the amount of wires inside the rubber coating, 2nd is the material the wire is made of (copper, steel, tin) 3rd is the amount of rubber shielding around the outside. Your cheaper wires will have half the amount of strands on the inside made out of a different material, and the rubber coating will be smaller. That is what I meant by shielding.

Now if you stack your grounds you can raise the resistance at the grounding point. Electricity will follow the path of least resistance, which in some cases will be through the RCA's (groundloop). Same thing you were saying. Plus grounding to the sheet metal in your car is not the best way to ground a system. (because as you said the sheet metal is not the best conductor). By stacking the grounds and grounding it to the sheet metal you are asking for groundloop problems.

The whole object to what I was saying is space your wires apart, and do not skimp and buy cheap wire. Do it right the first time to keep any problems from comming up. Anything is possible when you are dealing with electricity. Granted it is supposed to work a certain way, but if you have had to trouble shoot things you will know that anything is possible.

 

[helotaxi 5,000+ posts]

It does not matter if it is AC or DC. There is an electronic field around all wires. (that have power going through them) The field size can be different sizes based of the amount of power going through the wire, and the amount of sheilding on the wire.

It's a mag field actually and I am fully aware that it is there.

The wire that your stereo is using is AC, but that too can pick up a signal from your DC power wire if they are run to close to each other.

Noise induced in an AC circuit must come from a fluctuating mag field. A high power AC transmission cable could do that if it were close enough to your RCAs but a DC power cable with its pretty much constant mag field is not going to do a thing. I have heard of problems with people getting noise from their exciter box from a high power ignition coil but that is pulsating DC which is basically AC.

YES HELO rubber is used as a shield, so you have seen sheilded power wire.

No, rubber is an insulator and has zero effect on a mag field.

Take a look at different wires, and you will see what I mean. The cheaper wire is cheaper for a number of reasons. 1st is the amount of wires inside the rubber coating, 2nd is the material the wire is made of (copper, steel, tin) 3rd is the amount of rubber shielding around the outside. Your cheaper wires will have half the amount of strands on the inside made out of a different material, and the rubber coating will be smaller.

The number of strands only affects the flexibility of the wire I'm not willing to pay $1 a foot more for wire that is just ashade more flexible. All power wire that I have seen/used is OFC copper regardless of price. It is the best conductor for the money. The Silicone jacket is only there to protect from shorts, it provides no "shielding" in an electrical sense other than shielding from shorts. Different companies use different compounds for flexibility and chem/heat resistance reasons.

Now if you stack your grounds you can raise the resistance at the grounding point. Electricity will follow the path of least resistance, which in some cases will be through the RCA's (groundloop). Same thing you were saying. Plus grounding to the sheet metal in your car is not the best way to ground a system. (because as you said the sheet metal is not the best conductor). By stacking the grounds and grounding it to the sheet metal you are asking for groundloop problems.

If you stack the grounds of your two amps the ground potential between them will be basically zero. You then only have to worry about the difference between the HU/processors and the amps and not between the amps themselves.

The whole object to what I was saying is space your wires apart

I've zip-tied power and RCA cable together; no noise.

and do not skimp and buy cheap wire.

For the transmission of DC, OFC wire is OFC wire is OFC wire. If you want to pay several dollars a foot for Stinger Expert I'm not going to tell you don't do it, it's your money after all, but if you want to buy $1 a foot 1/0 OFC welding cable I would say that you are smarter with your money and you will not see a difference in performance from the wire and the guy who bought the cheap wire will have another $100 or so to spend on better speakers.

Anything is possible when you are dealing with electricity. Granted it is supposed to work a certain way, but if you have had to trouble shoot things you will know that anything is possible.

If you indeed do it right, knowing how it will work, you won't have unexplainable problems. Any problems that you do have can be fairly quickly resolved by eliminating all the things you did right to begin with and at that point will usually end up being a faulty component rather than wiring.

 

[nosaj070 10+ year member]

I think Helo is a good example of why the US military pretty much kicks ***. Thank god he's here, this forum has been losing a lot of knowledgeable people left and right.

 

[Benny212 10+ year member]

Are they both grounded to the same point? Are the ground wires as short as possible? Is the ground point sanded to bare metal? Is the ground point a major piecs of sheetmetal on the car? If you can answer all of these questions yes, then the problem is likely with the ground on your headunit, not your amps. Try regrounding your headunit to a major piece of metal under the dash (not part of the dash but rather a spot on the firewall or such). As a last resort you can run a ground wire from the HU back to the spot that the amps are grounded.

well, I can answer yes to all those. So i guess this weekend I'm gonna try regrounding my HU. Hopefully that will fix things. What size wire should I use to reground the HU? I was thinking just match the size of the power wire. Thanks for your help.

 

[indosia 10+ year member]

Make sure that your amp, h/u, crossover ect. are mounted so they are not touching any metal. Pull out your h/u and make sure it's case is isolated from chassis ground. Try turning down the gain on your amp. Alt. whine is usually a result of multiple and or poor ground paths.

And it's important to use high quality, high temperature multistrand ofc cable. Also good if it has a flexible gas and oil resistant jacket.

 

[pavengmike6 10+ year member]

Well Helo is not the only one that is in the military. Helo should take part of my name and apply it to all the HELOS in the military, and he will know what I do.

 

[helotaxi 5,000+ posts]

Yep. I know several of the pilots in that unit, if you are active duty. I was working a slot in that A/C but the pipeline was not open when I was up for an assignment.

 

[Benny212 10+ year member]

well, I still haven't had a chance to try regrounding the H/U but I forgot to mention some stuff in my previous posts. When I unplug the RCA cables from one of the amps the whine stops. I've tried grounding at two spots, both of them resulted in the whine.

to respond to indosia, I think the H/U is touching some metal because it is mounted behind the dash to a peice of metal where a H/U is normally mounted. I'm going to check if the amps are touching any metal when I reground the HU, probably this saturday.

thanks for the help

 

[indosia 10+ year member]

Ya it's a ground loop. Put some electrical tape over any metal your h/u might be touching.

 

[Benny212 10+ year member]

Ok, I finally got around to messing with the H/U ground today, here is what I tried.

Two ground spots up front and one in back (the same spot as the amps are grounded to). All three didn't work. Also I made sure the H/U wasn't touching any metal and I covered the spots that were with electrical tape. I did notice however, is that when the ground wasn't plugged in at all the H/U still turned on. I'm guessing that this means it is grounding somewhere else and that spot is the source of the problem. I'll try to track that spot down the next time I have an hour free. if someone has any other ideas or tips I could try I would really appreciate it.