Wire Length Calculator

[NoxMorbis]

I'm not having any luck finding what I think is a proper wire gauge calculator for amp to speaker runs. Some say "enter length" but they don't specify if the 'length' is one way or x2 for both ways, to and from the speaker, and CCA vs Copper drops. (Although the price between the two is really negligible for my usage and I'll most likely use copper in order to use smaller gauge wire.

Any links?

PS--I did this a couple of years ago, but I actually did it the hard way by getting the resistance of the wire and speakers and calculating it that way. But I've forgotten if I should use x2 the one way run length and I'm too lazy to look up the specifics of my wire resistance etc. lol

 

[Doodski]

Just use 12AWG copper. It's not overly expensive and it will be in stock. Odd sizes are sometimes not in stock or they cost more due to not selling many.

 

[DVDdoug]

Both conductors are in series with the speaker so the total resistance is "round trip" Double the length.

 

[Speedskater]

Most of the charts are about cable length, not the sum of the conductor lengths.
Now that copper is pricey, the difference is the audiophile's piece of mind with the larger conductors.
When listening to music they will sound the same.

 

[Doodski]

If you are running a long run then use 12G and if it's only 3meters per side then use 12G. Voila! That's what pretty much everybody buys.

 

[pjug]

You can use Benchmark's spreadsheet. If you know your speaker's impedance curve (max and min) you can then find the wire gauge that gives better than whatever variation in frequency response you are OK with. edit: in the spreadsheet the length considers round trip, so just enter the one way length.

Audio Myth - "Damping Factor Isn't Much of a Factor"

Myth - "Damping Factor Isn't Much of a Factor" Myth - "A Damping Factor of 10 is High Enough" Myth - "All Amplifiers Have a High-Enough Damping Factor" Where did these Myths Originate? These myths seem to trace back to a well-known paper (PDF) written by Dick Pierce. His analysis shows that a...

benchmarkmedia.com

https://cdn.shopify.com/s/files/1/0321/7609/files/DampingFactorCalculator.xlsx?v=1591278482

 

[fpitas]

10AWG zip cord is available for cheap at Amazon. I used that for my 4 ohm woofer runs.

 

[Prana Ferox]

I have never seen anyone or any resource talk about two-conductor wire and then give data that only applies to one of the two conductors. So assume a '10 foot cord' is a ten foot length of two ten-foot conductors. It's an AC signal so there's not really a 'going to' and 'coming from' in the first place.

 

[Blumlein 88]

10 gauge is 1 ohm per thousand feet one way. So .1 ohms for 100 ft one way or 50 feet of speaker cable.

12 gauge is 1.6 ohms per thousand feet one way. So .16 ohms for 50 ft of speaker cable.

16 gauge is 4 ohms per thousand feet one way. So .4 ohms for 50 ft of speaker cable.

While the Benchmark article is correct, and good info, I think it is a little-bit overkill for most cases. Using it as a guideline, for most speakers 10 gauge is good to 20 ft, 12 gauge to 12.5 feet and 16 gauge to only 5 feet. With some simplifying assumptions. This is assuming nearly zero output impedance for the amp and 2 ohm minimum equivalent for the speaker. Heck if your speaker gets below 2 ohms, you might want to have a bit extra in the cable anyway. Unless you have a highly unusual situation I'd probably multiply those lengths by 1.5x.

 

[NoxMorbis]

Just use 12AWG copper. It's not overly expensive and it will be in stock. Odd sizes are sometimes not in stock or they cost more due to not selling many.

12? HUUUUUUGE and WAAAAAAAAAY over kill. LOL.

 

[Chrispy]

This is a popular one http://www.roger-russell.com/wire/wire.htm#wiretable

 

[NoxMorbis]

10AWG zip cord is available for cheap at Amazon. I used that for my 4 ohm woofer runs.

You must be looking at CCA not pure cooper?

 

[Doodski]

12? HUUUUUUGE and WAAAAAAAAAY over kill. LOL.

Most peeps here are using 12G for long or short runs. It really fits well in both of those parameters. Try amazon for good prices.

 

[NoxMorbis]

10 gauge is 1 ohm per thousand feet one way. So .1 ohms for 100 ft one way or 50 feet of speaker cable.

12 gauge is 1.6 ohms per thousand feet one way. So .16 ohms for 50 ft of speaker cable.

16 gauge is 4 ohms per thousand feet one way. So .4 ohms for 50 ft of speaker cable.

While the Benchmark article is correct, and good info, I think it is a little-bit overkill for most cases. Using it as a guideline, for most speakers 10 gauge is good to 20 ft, 12 gauge to 12.5 feet and 16 gauge to only 5 feet. With some simplifying assumptions. This is assuming nearly zero output impedance for the amp and 2 ohm minimum equivalent for the speaker. Heck if your speaker gets below 2 ohms, you might want to have a bit extra in the cable anyway. Unless you have a highly unusual situation I'd probably multiply those lengths by 1.5x.

LOL yeah, if you get below 2 Ohms you probably want to call the fire department. But using 10 Gauge copper for 8 Ohm speakers is insanity.

 

[NoxMorbis]

Most peeps here are using 12G for long or short runs. It really fits well in both of those parameters. Try amazon for good prices.

CCA or Copper?

 

[Doodski]

CCA or Copper?

Nobody who knows buys CCA. It's pure copper that is desired.

 

[RayDunzl]

I'm an outlier:

My speakers go below 2 ohms up high.

My speaker wire is 2AWG THHN since I had it, and the terminals, and both the speakers and amplifiers can accept it.

For no reason other than I could (and did). It all came from my scrap box.

They're not flexible, and there's no need for them to be.

Those are 1/2 inch (13mm) nuts for scale.

 

[NoxMorbis]

This is a popular one http://www.roger-russell.com/wire/wire.htm#wiretable

THANK YOU! This is what I was lookng for!

I also rember being con fused when he said;

"In the early speaker manuals, starting with the XR5, I included a chart for estimating the maximum wire lengths for various sizes of copper wire needed for 4 and 8 ohm loads. I have expanded it on this page to include 2 and 6 ohm loads as well. It was based on the resistance of the speaker wire not exceeding 5% of the rated impedance of the system. The wire length is for TWO-CONDUCTOR wire. This includes one wire out to the speaker and one wire back again."

Is his table below total wire length as stated in the table, or Length *2? I think I actually did figure that out on another forum a long time ago, and I "think" his table is *2, as in if you ahve a 20' run, that's really 40'.

 

[Doodski]

THANK YOU! This is what I was lookng for!

I also rember being con fused when he said;

"In the early speaker manuals, starting with the XR5, I included a chart for estimating the maximum wire lengths for various sizes of copper wire needed for 4 and 8 ohm loads. I have expanded it on this page to include 2 and 6 ohm loads as well. It was based on the resistance of the speaker wire not exceeding 5% of the rated impedance of the system. The wire length is for TWO-CONDUCTOR wire. This includes one wire out to the speaker and one wire back again."

Is his table below total wire length as stated in the table, or Length/2:

View attachment 279360

I would be looking at the available wire and for what expense to you. Things may change when you start pricing out the wire.

 

[Chrispy]

THANK YOU! This is what I was lookng for!

I also rember being con fused when he said;

"In the early speaker manuals, starting with the XR5, I included a chart for estimating the maximum wire lengths for various sizes of copper wire needed for 4 and 8 ohm loads. I have expanded it on this page to include 2 and 6 ohm loads as well. It was based on the resistance of the speaker wire not exceeding 5% of the rated impedance of the system. The wire length is for TWO-CONDUCTOR wire. This includes one wire out to the speaker and one wire back again."

Is his table below total wire length as stated in the table, or Length/2:

View attachment 279360

Does your speaker wire have two conductors? That's the usual situation. Another table https://www.audioholics.com/audio-video-cables/speaker-wire-gauge