The Bose Companion 5 speaker system (a sub-woofer, a left speaker and a right speaker) is meant to be used on a computer desk so the cables are pretty short. I wanted to place them on bookshelves further away from the sub-woofer but Bose does not sell extension cables and I didn't want to cut the original cables when extending them.
Each speaker is connected by a cable that has 4 wires inside the cable sleeve and it so happens that each of the 4 wire perfectly fits a standard breadboard wire (a male breadboard jumper wire to the speaker end and a female breadboard jumper wire to the sub-woofer end).
Step 1: Parts
To make an extension cable you will need:
1) A long network cable with 8 wires inside the cable. Or any other appropriate cable you can find.
2) 8 male-male breadboard jumper wires, can be purchased here, for $2.
3) 8 female-female breadboard wires, can be purchased here, for $2.
4) Soldering iron and lead
5) Electric Insulation tape
Step 2: Build
1) Cut the network cables heads off.
2) Cut away 1.5 inches off the network cable sleeve to expose the 8 multi colored wires.
3) Strip the 8 wires of the network cable on both ends (i use a pair of scissors with gentle pressure and twisting)
4) Remove the plastic clips from both ends of the 8 female-female breadboard jumper wires (there is a little clip you can lift up)
5) Remove the plastics clip from one end of the 8 male-male breadboard jumper wires.
6) Solder the male-male jumper-wires to one end of the network cable and the female-female jumper-wire to the other end of the network cable. Tip: when soldering, fit the network wires inside the metal clips of the the jumperwires.
IMPORTANT: Make a note of the colors! You want to have the same color jumper-wires on both ends of the network cable.
Example: Blue Female Jumper -- Blue Network Cable -- Blue Male Jumper
Grey Female Jumper - Blue/White Network Cable - Grey Male Jumper
7) Using Electric Insulation Tape, tape all the soldered parts.
8) Attach the male jumper wires into the speakers and tape down.
IMPORTANT: make a note of where you plug them in so as to match it to the correct place in the sub-woofer.
9) Attach the female jumper-wires into the sub-woofer.
10) Tape down the network cable so the ends don't accidentally get pulled out.