Todd - here's an 18 gauge Van den Hul speaker cable made specifically for speakers. High quality silver plated copper you could use for the signal - cheaper than solid silver and very effective
http://www.vandenhul.com/products/cables/speaker-cables/single-lead/scs-18-halogen-free
I used VDH cables for many years and they always provide excellent sound quality.
Another option would be a 16 gauge silver plated Mil Spec wire from Take Five Audio
https://www.takefiveaudio.com/products/334-mil-spec-16-awg-silver-plated-copper-wire-green-cryo-trea...
If you go with a helix design you can ease up on the number of "winds" per in inch.
I would start with one wind every inch and then try 3-4 winds per inch.
The problem will be keeping the neutral evenly wound. This might help
https://www.takefiveaudio.com/categories/118-convoluted-teflon-tubing-flexes-without-kinking
I've also found keeping the two conductors completely separate by an air gap wider than 1/2" worked very well - so give that a try as well
Keep me/us posted on your findings - Thanks :-)
http://www.vandenhul.com/products/cables/speaker-cables/single-lead/scs-18-halogen-free
I used VDH cables for many years and they always provide excellent sound quality.
Another option would be a 16 gauge silver plated Mil Spec wire from Take Five Audio
https://www.takefiveaudio.com/products/334-mil-spec-16-awg-silver-plated-copper-wire-green-cryo-trea...
If you go with a helix design you can ease up on the number of "winds" per in inch.
I would start with one wind every inch and then try 3-4 winds per inch.
The problem will be keeping the neutral evenly wound. This might help
https://www.takefiveaudio.com/categories/118-convoluted-teflon-tubing-flexes-without-kinking
I've also found keeping the two conductors completely separate by an air gap wider than 1/2" worked very well - so give that a try as well
Keep me/us posted on your findings - Thanks :-)