In my last post on cables, one of the respondents replied with a couple of great links. One of them was to Roger Russell’s site on a discussion about speaker wire. In that article, he had a very useful table on wire gauges and maximum cable lengths you should use. I grabbed the table, reformatted it for GuitarGear.org. Here’s the table:
|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||16 feet max||24 feet max||32 feet max|
|16 AWG||12 feet max||24 feet max||36 feet max||48 feet max|
|14 AWG||20 feet max||40 feet max||60 feet**||80 feet**|
|12 AWG||30 feet max||60 feet**||90 feet**||120 feet**|
|10 AWG||50 feet max||100 feet**||150 feet**||200 feet**|
The “**” indicate that in reality a 50 foot cable length is actually optimal.
I dig information like this because it’s a great reference for when I’m buying cables.
With speaker cables, what you’re concerned with is not capacitance, like you are with instrument cables. What you’re concerned with is resistance. You COULD use a material that has much less resistance than copper, like gold, but you’ll get much more bang for the buck by just going up a gauge (down in number). Personally, I just use 12 gauge wire for my speakers, and the lengths are only 4 feet, so I can use pretty much any load and be assured that I won’t create too much resistance between my amp and cab.