Ocos speaker cable is a coax design and exhibits no loss out to 200 feet. Double runs improve bass extension. This cable is available through Sumiko Corp. They have an office in the East Bay (San Francisco Bay Area)
This cable is fast and is very good at imaging. They come with adapters to convert the coax termination to spade. They are about the same diameter as RG-59 cable used in cable tv. However that's where the similarities end. I am using my Ocos with Nearfield Acoustics Pipedream speakers.
A search on Audiogon indicated the phone number: 510-843-4500.
And the best part. Unless you want to spend 100.00$ a foot or more, you can't beat the Ocos. Yes that's an opinion. Maybe it's 92.00 or more but after all it's just an estimate. I find this cable used at about 10 to 15$ a foot. Most used lengths aren't as long as 50 feet. Being coax in doesn't lend itself to splicing well, so lots of short length are not recomended. Sumiko terminates your lenght with a crimped metal terminal that friction fits into the spade adapter. Two adapters are available, black and red. Some tweeters exhibit "ringing" and the red termination helps avoid this. Sumiko can explain the science.
New, Ocos cable is somewhere around 20$/ft.. It's worth a call to Sumiko. Do a google search under ocos sumiko to see reviews by other owners.
Summing it up: it's good out to 200 feet, great imaging, small and flexible but stiff enough to feed up through walls, smooth frequency response, and in multiple runs it just gets better. And it's cheap!