I make pretty nice cables from CAT5 or CAT6, high purity copper and Teflon insulated, also plenum coated (fire/off-gas resistant)... Cut the sheath back at least 6 inches, and separate out all the singles and strip them about 1 inch to expose bare copper (solids or strands, depending on type)... Now, pick all the solid colors and twist together out to the ends and really twist the copper ends together carefully and smoothly; heat this a bit with your solder iron and flow your choice of solder in between the bundled/twisted ends and the hot iron... I like a softish solder so that my speaker and amp connectors "bite" into the ends, but you may like harder silver solder. Trim the soldered end to preferred length.
Repeat for the "stripes or whites" part of the wires ( and do the other end too)... put on bananas, pins, spades if you prefer, but I play with so much gear that can't use them, and I don't bother with them.
TEST FOR OPEN CIRCUIT BEFORE USING... Use a ohm meter to make sure that you crossed no strands/colors/stipes/whites...
With many of these CATn cables tossed away every day for the simple offense of losing a cable end, or just a locking tab, you all probably have a big supply of great cable to learn on and use close at hand, and a wide range of colors too!
They sound nice too I think, though I don't hold much to cables sounding like anything if heavy enough for a low voltage drop on the run they are used for! I had/ have some of the first big copper snakes sold as speaker wire... Still use it for my mains that never switch out of the system and still hate how stiff and fat and hard to terminate/insert/clamp they are.