Speaker Cable Spacers

There is a capacitance between the two cables that carry power to the speaker.
As the two cables approach, the capacitance increases. As a result, high frequency treble sounds are weakened. 

Spacers prevent attenuation of high frequencies.

Modeled with TPU filament. The cable is AWG18. The outer diameter of the cable is 2mm.

The distance between wires is 20mm.

When I measured the line-to-line capacitance of the completed speaker cable, It was about 36pF when stretched in a straight line, and about 35pF when put together as shown in the picture.