Adventures with CAT 5 Speaker Cable
(Lazy 4-braid Cat 5 Speaker Cables)

I was curious about using CAT 5 for speaker cables since I had a pile of "Mohawk/ CDT E153612 Megalan (tm). . .M56168" scraps laying around. I wasn't too keen on all the braiding that Chris VenHaus advocated ( Chris VenHaus's Cat 5 Cable. ) So for the first version I got lazy and 4 braided 4 sets of CAT 5 wires.
(After I made my own "lazy" version of this cable, Chris's version of the cable is definitely on my to do list! Good job Chris!)

I first stripped the PVC outer insulation off by pulling the fiberglass string in the cable and ended up saying "Doh!" because I didn't wear a long sleeve shirts, gloves and safety glasses when I did it.  Even thought I was using a pair of needle nose pliers to hold the fiberglass, I still ended up being impaled with those nasty fibers.

The 115 inch long stripped sets of 4 twisted pairs had a light natural twist (about 1 turn/foot) so I decided not to braid the individual twisted pairs on this set of cables (more sloth).

I clamped the ends of the 16 sets of twisted pairs to a work table. Don't use your wife's nice dining room table! Note: The end of the cable in the clamp gets cut off after you are braiding, so clamp at the very end of the cable.

I then "figure 8" coiled the tails of the twisted cables until I had 3 feet of cable hanging loose. The circle diameter of the loop in the figure 8 coil was about 4 inches in diameter. The wire naturally took this bend with not much force. I lightly secured the middle of the "figure 8" with a pair of twist ties from a box of garbage bags. As I "4-braided" the cables, I would let more wire off the coil. These cables braided fast. I like the "rope" look of the finished cable a bit better than the 3-braid pictures I've seen too. (Proud papa syndrome again?)

The 4-braid goes like this:
Each color represents a set of 4 twisted pairs. The braid was fairly loose (not limp). Each braid ended up about 1 3/4 inch apart. The numbers on the side of the diagram count the braids. Every four "4-braids" the overall pattern starts over.

After the 4-braiding was done, I untwisted and separated out 6 inches of the individual strands from each end. I put all of the striped conductors to the left and the solids to the right. These were given a light twist by repeatedly and gently twisting the 16 individual wires so that the natural wave in the copper caused them to tangle into a reasonable looking twist.

Some of the individual wires were a little longer than others, so to make the cable look neat,  I cut the ends back to about 5 inches before I started stripping the Teflon (tm) off.

I stripped 1 1/2 inch off each wire, tightly twisted the exposed copper and solder the ends (Kester 44). I then crimped Radio Shack 278-311A Deluxe Snap Spade Connectors on the ends. (Yes I know this is not the best way to connect spade lugs to wires.) I used the Red cover for the striped and the Black cover for the solid wires.  After I ohmed them out, I hooked them up to the Paramours and Horns: I was favorably impressed. Everything seemed tighter and cleaner even with no break-in time. Before I installed these cables, I was using Tara lab's "Space and Time" cables.

Using a cheap hand held capacitance meter I measured 2000 pF for the cable capacitance. Using a power amp with a 3 ohm output impedance feeding a 8 ohm speaker (2.2 ohm node impedance) the -3 dB point from cable capacitance is: 1/(2 * pi * 2000 pF * 2.2 ohms) = 36 MHz.

I don't know what my output transformer's loading capacitance is, so I don't know if the extra capacitance will pull the - 3 dB point below the CB radio band. ;-)

(1) 16 AWG # 24 wires is the equivalent to AWG # 12. Every time you put two wires in parallel, they drop 3 AWG.

Two # 24 = one # 21
Four # 24 = two #21  = one #18
Eight # 24 = four #21 = two #18 = one # 15
Sixteen #24 = one #12
(2) I've been told a crimp covered with a heat shrink filled with thermal set epoxy is the best connection. I believe it. I just happen to like solder and I don't know where to buy that special epoxy filled heatshrink (I really haven't looked very hard.)

(3) "Figure 8" coiling of cords and cables tends to not get tangled up like when you make circle coil of wire.

(4) More ways to braid can be found here:  Braids

(5) From the Mohawk cable page, the following are the characteristics for the CAT 5 cable I used (remember, I used this cable because it was scraps I already had):

Plenum 4 Pair (100 ohm input impedance)
24 AWG
UTP FEP Teflon
Jacket: **  White ThermoPlen *
.186   4.7 24   36 UL, c(UL)
(6) The leakage inductance of the transformer working into a 8 ohm load will make the -3 dB point much much lower than 36 MHz.

I like these cables enough that I am now wanting to pre-braid the individual 4 twisted wires in the cat 5 cable before I do the final 4-braid.

I'll probably end up using Chris's 3 by 3 by 3 braid (27 strands of wire.) My fingers are starting to ache already.

You can also do 3-braids of three 4-braids and 4-braids of four 3-braids etc.

First edition 4 Jun 2001 Last update 7 Jun 2001