our canadian electrical code book and nema standards list the current carrying capabilities of the following wire sizes as such 14 ga =15 amps 12ga =20amps 10 ga=30amps 8 ga=40a 6ga=60amps and so on

 

Um, based on what voltage at what length?

The factory runs 50 amps through 10 gauge.

Under test conditions I have pushed 80 amps through 10 Gauge wire with no heating of the wire, so again I wonder what length wire they are referring to.
A 450 amp battery cable is only 4 or 6 gauge.
Chris

 

Exactly Chris you have made my point for me, 80 amps thru a 10ga wire. So then ask yourself how much overkill really are these huge honkin speaker cables. Wouldn't want too run that 10ga at 80 amps too long, it is going to heat up. Thats what the electrical safety codes are trying to guide us to. Voltage and length do not enter in to the equation. Amperage is amperage be it at 5 amps at 600 volts or 5 amps at 5 volts you still have 5 amps flowing in the conductor/wire. As you can see by my previous posted equation, how big an amp it takes to generate 20 amps of speaker line current, and that would have to be running wide open all the time. That 450 amps thru a 4 or 6 ga cable is only for short periods of time. Chris key that starter 20 times in a row, then grab the cable tell me what you feel. The electrical code current ratings are based on continous operation, and of course have a certain amount of safety factor taken into consideration. If you ever have nothing to do. Lift your positve battery cable and add in a small link of 14 ga wire (thats where the concept of the fusible link comes from)then key the starter, and stand back and watch the power of current flow.By the same token someone mentioned running 18 ga speaker wire on an 800 watt amp and i also would agree that size of wire for that application would be a touch on the small side. Length of the wire effects the voltage and not current. Now if my memory serves me correctly, if i had a 14 ga piece of wire 300' long, and i applied a true 120volts to it. I would lose in the neighbourhood 4 to6 % over that length, so i would be looking at roughly 113 volts at the other end. Thats why power transmission lines run at very high voltages to fight the voltage drops over long distances. The lower your starting voltage ,the more pronounced voltage drop becomes, but not much effect can be felt in the short wire runs in cars. The point of my whole little narrative is that you need for people to under stand that voltage and current are two completely different things. This also gives me an chance to speak out against this scam perpurtrated by these people who sell this highpriced speaker wire to the less informed amongst us. My words on that monster cable? monster scam!

 

As an Electrician and Electrical tinkerer of sorts I would like to also chime in and say that the gastly size of speaker wires is a bit rediculous.No practicality,just for show.The only wire you really should be concerned about getting the proper size for is your amp.(speaking of fires I hope all of you are smart enough to fuse your power wires,and use a rubber sleeve to pass power wires through your firewall,Ive seen many burned up vehicles caused by these simple things)Voltage drops do occur over a "long" length of wire.(over 100ft)Everything to the NEC electrical code has to be rated at 125% of continous load.But what Ive seen in these a past posts are truly correct.The current being pulled is what causes your wire to get hot and insulation to melt..You cant possibly compare audio wire to electrical wire,It just isnt the same.

 

Ohms law does not care if it is audio or electrical or otherwise. I agree however that the NEC or CEC has nothing to do with the wiring of your car. Nor does it have anything to do with actual current carrying ability of a wire. As you said the NEC uses a 125% rating. This is not the current carrying limit of the wire either, it is the current carrying limit of the installation to prevent your houses from burning down.

 

You are right Norm the electrical code has nothing to do with wiring your car. So how do YOU determine the safe current carrying capacity of wire.Run it till it smokes and then back it off a few amps. The electrical code does give you a sensible guide to go by.I haven't had an electrical fire in any of my installs ever. Ohms law only tells you whats happening in the wire it doesn't limit the current in the wire, but i think that a code that provides a safe sensible guide to keep your home safe, might not be too bad a guideline to wire most things to including your car. After all do you think maybe tens of thousands of skilled tradesmen could have been wrong all along. So when YOU determine the the current carrying capabilities of wires, please do let the rest of us know so we can start wiring everything to Norms code. There was a point to your post wasn't there? so get to it!

regards Robert R Konarski o/o of konwire solutions

 

2088bob, I think you probably know quite a lot, but try as I might I can not puzzle out your posts. For reasons of your own you are not using spacing, punctuation, capitalization, etc.
This makes your posts virtually illegible.

Do to the way they are written they are almost totally undecipherable to anyone trying to read them.
This does not reflect on the content.

I am not trying to hassle you, I think you have something to say and are trying to share your knowledge and insight.
Typing in a mono-block does not do that, it is actually worse than those who type with the Caps lock on.
Again, just hoping to help, I’m not flaming you.
Chris

 

Chris you are 100% right. I do forget about punctuation, capitalization etc. And I have no real excuse for it, except maybe laziness.So for that I apologize profusely, it takes a post like yours every so often to bring me back in line. I take no offence to your comments, and might add grammar and sentence structure were never one of my strong suits. I will make a concerted effort to improve on this downfall. Thanks Chris

regards Robert R Konarski o/o Konwire Solutions

 

Example of what really happens in a typical set-up. Given an amp producing 1000 watts into 4 ohms.
Gauge of wire------ *12AWG*---- *22AWG*
Length of wire ------- 5ft. ******** 5ft.
Resistance of wire --- .06ohms **** .16ohms
Current Draw -------- 15.56A ***** 15.2A
Amp OutputV@amp -- 63.25V ***** 63.25V
Amp OutputV@sp.---- 63V ******* 60.79V
Power output@sp. --- 992.11W *** 923.93W

The voltage drop is there. The power drop is there, which amounts to less than 1/2dB in SPL, not an audible amount. Taking your set-up to 2 ohms changes all that. While 12AWG may be close to ideal for 4 ohms in the above example, it will not be "AS" ideal with 2 ohms. It would work and would still have inaudible effects, but gee whiz, speaker wire is cheap. Let's all get the correct size and let our amps do their thing. As an exaggerated example, 6 gauge would allow the above amp to produce 996+watts. The resistance of the wire is almost nonexistant, and the voltage drop to the speaker from the amp's terminals is less than .1V. Is it overkill? Let the buyer and user be the judge. It certainly is better than 22AWG, which would limit the amp to 856watts, with 40X the resistance of the 6AWG, and a voltage drop of over 3V from the amp to the speaker. The loss in SPL would be getting to the point of being audible to the listener. On top of that, there's always the issue of being sensible and safe. A 2 ohm set-up increases the the current draw on the 12 AWG from 15.5A to over 22A. This is why you want the correct wire.

The bottom line is, if the wire isn't CAPABLE of matching up with the rest of the components in the system, those components cannot work to their optimum.

By the way, I used 22AWG only as an example. If anyone is really using it for subwoofers, WOW!!!

 

Hey Bob, there are charts available that show actual current carrying limits for different wire gauges. Google it. There is no need to create a Norm's code nor any reason to be a ****. The point of my post is that home wiring codes have nothing to do with car wiring but Ohm's law applies to both. Reading comprehension not your strong suit? The electrical codes are written such that you could short out your outlets and draw full current (125% of labeled limit (not physical limit)) until the breaker trips without the wires melting or catching on fire. Speaker wire size just needs to be big enough to carry the signal without loss. Of course you do not want to use too small a wire for anything in your car. There is potential for shorts and fire there as well but on a greatly different scale.
Show me the 12 volt car wiring section in the NEC or CEC.

97f250 has it right.

 

If I am reading this right, you are pushing the example to an extreme. Really, 22 vs. 12 wire at 15-22 amps?
You’re kidding, right?

22 amps to a speaker would only happen on an amp that is drawing 100 amps of power at 12.5 volts. That's 1250 RMS amps or about 3000-4000 watt rated amplifier.

Remember, we are talking speaker wire here, not Sub woofer wire.
And not power/ground wire. This is the wire that carries sound from the amp/headunit to the speaker itself.

Who uses speakers that can handle 300 RMS?

We are talking regular trucks with regular sound systems, not competition.

And look at the drop at say one fourth that output, still many times what real world people are using. The loss drops to 16th. Or 1/16 of an amount that may not be audible at the full amount.

And even on a sub, except in competition how many people are gonna be putting that kind of power to their speakers? Of course the guys with two or six 12 inchers may be doing that, but they will be running big wire for show anyway.

The choice is not always 22 or monster. A nice 16 gauge wire will carry more sound than any non-show truck will ever use. And I truly doubt that anyone in the real world could tell if you put 22 or 12 in a regular truck. Or 22 vs. 6 gauge wires.

Overkill in projects is an American tradition, but don’t think that just because someone changes their oil every 100 miles, washes their truck every day, rotates their tires weekly and uses 4 gauge wire on their speakers that they are doing it for any practical reason. They are just doing things like this because men love overkill.

Hey, I like shooting rabbits with my 458 WM as much as the next guy, but I don’t try to tell people I NEED the Magnum to pot bunnies…
Chris

 

The purpose of posting replies here is to inform those who ask questions. I clearly stated that 22AWG was for the purpose of an example. And, do you think that there aren't knuckleheads around who try speaker wire that is too small? When the set-up is capable of drawing over 20 amps, which 1000 watts IS capable of into 2 ohms, the speaker wire will try to draw that current, even if it isn't capable. That's where problems occur. It's like configuring your amp to drive a 1 ohm load even though its outputs are not capable of anything lower than 4 ohms. The outputs will still TRY to deliver the current. 22AWG wiring, if anyone was to use it, would TRY to deliver the current from the amp, although unsuccessfully. That's the whole point of this thread. USE THE CORRECT WIRE.

And, would you care to explain the difference between speaker wire and subwoofer wire?

My component speakers are rated to handle more power than my subs. What's the point of asking, "Who uses speakers that can handle 300 watts RMS?" That has nothing to do with this discussion. If the speaker can handle 25 watts RMS or 1000 watts RMS, it's immaterial to what the current draw is from the amp. Only the resistance matters.

What does the next question have to do with this discussion? It doesn't matter if the system is competition or a daily driver.

The comment about 16 gauge being able to carry "more sound" than any non-show truck will ever use is ridiculous. How do you know what someone has in their daily driver, or as you put it, "regular truck"? 16AWG is probably suitable in the vast majority of cases, but it is NOT suitable if it cannot handle the current from the amp. General statements like that are one reason so many newbies are confused about what is true and what is not.

The rest of your response makes no sense to me for the purpose of it adding anything to this thread.

Like I said, overkill is for the user to decide. That's the great thing about this hobby. We can all do what we want, right or wrong.