I want to know where I can buy some supplies that will allow me to make my in-wall speaker cable look like this or this. I saw parts exrpess had a kit you could buy, but it looked like it had a bunch of stuff I wouldn't need. Any advice?
Yep, it's just techflex-- you can even call them and they'll send you a complete sample kit with all their products (including kevlar and teflon stuff, lol).
The second one uses cheap PET techflex, their cheapest product- which you can get from Markertek for like $17 a roll (for the stuff for about that size). The blue one seems to use something a little nicer, but it's probably still a techflex product.
Buy the CC (clean-cut)product it can be cut with scissors, expands well and won't fray easily. Unless you want fancy disco colours, stripes or intend to use your cables in combat (Kevlar)its all you need. Tech-Flex does make a cheap covering (PET). Its thinner and needs a hot knife to cut properly, avoid it for DIY projects.