Low-Inductance DIY Hi-Fi Speaker Cables
Low-Inductance DIY Hi-Fi Speaker Cables
The 1.618wr speaker cables turned out well and I thought I would share the instructions and results. I am using these DIY low-inductance speaker cables with my DIY Hi-Vi 3-Way Speakers. The speaker cables use 16AWG strnaded copper wire, a total of 4 x 16AWG wires for each speaker cable conductor which give an equivalent AWG of 10 (see American Wire Gauge (AWG) Table for reference). The following materials were used for the 1.618wr DIY Speaker Cables:
Table 1: Required Parts for DIY Speaker Cables
|Parts-Express Part #||Item Description|
16 AWG Black Primary Wire 100 feet
16 AWG Gray Primary Wire 100 feet
Techflex 1/2" Expandable Sleeving 25 ft
Banana Plugs (2 pair)
Scale the required materials for the length of speaker cable you will be building. Of course you can use your favorite choice of materials for the wire, sleeving and termination.
Photograph 1: Materials Required for the DIY Speaker Cables
The idea behind this speaker cable design is fairly simple. Four 16 gauge wires (resulting in a combined 10AWG) are used for each speaker conductor to lower the overall resistance of the speaker cable. With regards to the speaker cable geometry, the wires are twisted together in opposite directions (see photos and description for more details). This helps reduces asymmetrical field interactions since the wires are not on either the inside or outside of the cable more than any other wire. It also helps to keep the inductance of the overall speaker cable at a minimum. For speaker cables, low-inductance is required to prevent attenuation of the high-frequency response within the audible range.
Low-Inductance DIY Hi-Fi Speaker Cable Construction
Construction of the speaker cables is fairly simple. Make four twisted pairs of 16AWG wire. The pairs are twisted together in a clockwise direction. You will need two sets of four twisted pairs for each pair of speaker cable.
Photograph 2: Four Twisted (clockwise) Pairs of 16AWG Wire
Next, take two of the twisted pairs from above and twist them together in a counter clockwise direction. Repeat this step for the remaining twisted pairs.
Photograph 3: Two of the twisted pairs twisted together (counter clockwise)
Using the above twisted cables, twist them together in a clockwise direction. Repeat this step for the remaining twisted cables.
Photograph 4: Twisted Wires for One Speaker Cable
Next, the Techflex cable sleeving is pulled over the twisted wire. Heat shrink tubing is used to hold everything in place. The ends are separated and then twisted together following the previously noted geometry.
Photograph 5: TechFlex Cable Sleeving, Heat Shrink and Cable Separation
To add a little personal touch, I used a $20,000 Markem-Imaje 7031 30 Watt laser to mark the wood. I work for the company, so I have access to this equipment. The wood is a large oak dowel that I simply drilled through. The oak sleeve was hot glued into place.
Photograph 6: Decorative Oak Sleeve
The ends of the speaker cables are terminated with locking banana plugs. Of course you can use whatever sort of termination you prefer. A photograph of the finished speaker cables is shown in Photograph 8.
Photograph 7: Banana Plugs used to Terminate DIY Speaker Cables
Photograph 8: Finished Low-Inductance DIY Speaker Cables
See the DIY Audio Projects Photo Gallery for a high resolution photo of the Finished Low-Inductance DIY Speaker Cables
Measurements: Low-Inductance DIY Speaker Cables
The end to end length of the speaker cables with the banana plugs is 13 feet (4 m). I measured the electrical parameters across the audible range (20Hz - 20kHz) and these are the average results for the 13 foot length:
- Resistance (R) = 0.0125 Ohms
- Inductance (L) = 0.600 uH
- Capacitance (C) = 0.850 nF
Table 2 shows a comparison of this DIY speaker cable project with some more expensive commercial speaker cables that are available. Note, the cable costs per foot do not include any cable termination.
Table 2: Speaker Cable Comparison
DIY Speaker Cable
12AWG Zip Cord
Cardas Quadlink-Five C*
Kimber Kable 4TC*
Kimber Kable 8TC*
Goertz MI 1*
* Commercial cables measurements are from the respective manufactures website.
** Approximately $500 for a complete terminated pair of 3 m (10 ft) cables.
As you can see, the electrical properties of these low-inductance DIY speaker cables are generally as good and in some cases better than commercial cable offerings that can cost many times more.