Get raw 12-4 cable from cameltraders.com, and get connectors from fullcompass.com (best price I have found if you buy 10 each. I get the gold ones).
I know this is a old post.
But for those that still use the search engine instead of posting a new questions.
I make allot of custom cables for people. Also being an Electrician by trade. If you don't have a wholesale number. cameltraders.com has great prices on raw / bulk cable as well as for
Neutrik connectors. Also check out automationdirect.com for
wire. They are second inline with great pricing. Also for Automation Direct, if you order more than $300 it's free shipping. That's a plus when it comes to paying for S/H on
wire that has a
bit of weight to it. For those that live in a area that has a Home Depot or Lowes. Look up Electrical suppliers in your area. You will get way betting pricing on SJ and SO
cord over buying from the Big Box stores. Some names to look for are Consolidated Electrical Dist also known as "CED" or PLATT
Electric. Also try googling for Electrical Supply.
I recommend using SJ
cord for making
speaker cords. The difference between SJ & SO is that SJ in the electricity world is rated for 300volts max. It has a little thinner
jacket compared to the SO type
cord jacket. SO
cord is rated for 600volts max. So why spend the extra money on SO when it's not needed and weights more to
hall around unless you just want a more durable
jacket cord.
Ampacity is the same for both types of cords types and only depends on the
gauge wire inside the
jacket. For what it costs to buy 14/2 or 14/4SJ. I recommend spending the little extra money and buying / using 12/2 & 12/4SJ for making
speaker cords. It matters when you want to run a
cord to a
speaker 100 or so feet away and need to couple two or three cords together to get it there.