IC design

If it matters, for my 3rd system, I am putting together one pair of ICs that will be 11" long and the other pair about 14" long. I guess there is probably little RFI/EMI in the area because the other 2 different systems, in different parts of the house, have almost no noise during silent portions of CDs. I have to put my ear within about 2 inches of the drivers to hear anything. The longest IC run for one system is 15 feet and it has the same quiet background as the other system with 1 meter ICs. This makes me question wether I need a drain wire in my DIY ICs that are to be 11 to 14" long. They are to be made with Eichman bullets, Neotch upocc silver, pure cotton sleeves and ptfe tubing. I have tested this 3rd system with 1 meter audioquest ICs and the backgroung noise is very low.

Thanks,
henrylr