Which wire gauge for a far away sub?

Printed From: the12volt.com
Forum Name: Car Audio
Forum Discription: Car Stereos, Amplifiers, Crossovers, Processors, Speakers, Subwoofers, etc.
URL: https://www.the12volt.com/installbay/forum_posts.asp?tid=68333
Printed Date: April 29, 2024 at 6:56 AM

Topic: Which wire gauge for a far away sub?

Posted By: vbel
Subject: Which wire gauge for a far away sub?
Date Posted: December 14, 2005 at 2:27 AM

I know that a 16 gauge wire is fine for subs, but what if the sub is located about 7-10 feet from its amp? Amp puts out 600 wrms and sub can handle 500 wrms. Will I be ok with 16 gauge?

Replies:

Posted By: dwarren
Date Posted: December 14, 2005 at 2:34 AM

Not according to the chart...https://www.the12volt.com/info/recwirsz.asp

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Posted By: menace2sobriety
Date Posted: December 14, 2005 at 3:20 AM

Wire Size	2 ohm load	4 ohm load	6 ohm load	8 ohm load
22 AWG	3 feet max	6 feet max	9 feet max	12 feet max
20 AWG	5 feet max	10 feet max	15 feet max	20 feet max
18 AWG	8 feet max	15 feet max	23 feet max	30 feet max
16 AWG	12 feet max	25 feet max	37 feet max	50 feet max
14 AWG	20 feet max	40 feet max	*******	*******
12 AWG	31 feet max	*******	*******	*******
10 AWG	50 feet max	*******	*******	*******

dwarren that's power and ground chart. Do you use 4 or 2 gauge for your 15" subs? posted_image

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Posted By: Ween
Date Posted: December 14, 2005 at 5:46 AM

hi,

this has been about posted before...use this to help

https://www.h-o-alternators.com/TechCalcs/speakerwireselectorassistanthoalt.swf

Posted By: stevdart
Date Posted: December 14, 2005 at 8:02 AM

The above mentioned group of calculators are handy...everyone should save them to file. The basic way to find how much amperage could possibly be carried through a wire so that you can select the proper wire gauge is to use Ohm's Law. Use two known factors to find the third.

posted_image

In this case you know the power output of the amp and you know the impedance load that this output is going into. So to find current use I = SQR(P/R). If the impedance load is 2 ohms and you know that the amp may output 600 watts, the current would be 17.3 amps. Peaks in the output would not have to be considered because if they occur at all they would be very short durations.

With 17.3 amps as your current, consult a wire gauge like those listed on this site (linked above by dwarren). The chart shows that 16 guage is good to 15 amps, so you could step up to 14 gauge. Mind you, the vast majority of the time the current will be well under 15 amps, so 16 ga. is what I would use if it were me. But just for the sake of being detail-oriented, the chart says to go to 14 gauge.

Using a beefier wire like 14 gauge, you wouldn't need to worry about the run length. But if you were to use 16 ga. you might also look at loss that could occur if your wire gets to be on the long side. You can see by using the calculator (linked above by Ween) that the loss with the smaller 16 ga. wire would be minimal on a 10' run (only losing 1/3 db)...so using 16 ga. would be fine in any event. Whatever wire you have on hand...

But if by chance you're running the amp at 1 ohm, you'll see a greater current and more of a reason to use 14 ga. speaker wire.

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Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

Posted By: vbel
Date Posted: December 14, 2005 at 1:34 PM

Thanks everyone for help. The amp will run at 4 ohm, and according to all these charts and calculations, 16 gauge is sufficient. I just have a 50 feet roll of 16, that's why I want to use 16.

Posted By: Francious70
Date Posted: December 14, 2005 at 3:22 PM

16 gauge wire will be fine. I would personally use 14 gauge, but that's just me. You'll want to start to go bigger than that if you speaker is located over 50 feet away.

Posted By: alpine_king
Date Posted: December 14, 2005 at 6:23 PM

haha

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1993 Ford Ranger.
Head Unit.Alpine CDA-9831
Front Speakers.Infinity 6010 Reference Series
Amp.Alpine MRD-M1005
Subs.3 Kicker CVR10
Rear Speakers.SPL CS-573
20" Boss 312's, lowered 3/4

Posted By: gus1
Date Posted: December 14, 2005 at 8:13 PM

Could double up the 16ga.... will give you an approx. 13ga equivalent.

Gus

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Wherever I go, that is where I end up......

Posted By: dwarren
Date Posted: December 14, 2005 at 9:41 PM

menace2sobriety wrote:

Wire Size 2 ohm load 4 ohm load 6 ohm load 8 ohm load
22 AWG 3 feet max 6 feet max 9 feet max 12 feet max
20 AWG 5 feet max 10 feet max 15 feet max 20 feet max
18 AWG 8 feet max 15 feet max 23 feet max 30 feet max
16 AWG 12 feet max 25 feet max 37 feet max 50 feet max
14 AWG 20 feet max 40 feet max
*******
*******
12 AWG 31 feet max
*******
*******
*******
10 AWG 50 feet max
*******
*******
*******
dwarren that's power and ground chart. Do you use 4 or 2 gauge for your 15" subs?

Damn right I do! You can never go too big.

Damn, that was a late night post, what was I thinking. I thought those were a little off posted_image

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Posted By: ophidia311
Date Posted: December 15, 2005 at 10:02 AM

i have 10 gauge running from my amp to my sub and then 10gauge on the sub itself. i did notice better sound from the sub but it certainly wasnt louder. and it wasnt the "well its bigger so it has to do something feeling" scine ive done it on all my friends cars and it was the same way. ill never use less than 12gauge on a subwwofer system again.

Posted By: Steven Kephart
Date Posted: December 15, 2005 at 7:05 PM

I personally prefer this site: https://www.bcae1.com/wire.htm

With 18 awg wire 10 feet long and 600 watts going through it, there will be a loss of .27db, .54 db at 2 ohms. This is completely inaudible.