I formed my basic believes that it is not hard to make a fully adequate cable for speakers and interconnects. I had the pleasurer of working with an engineer from Gore who designed cables for a living. Really high performance for studio and RF. We did a lot of measuring and a lot of listening. Once you get over junk level, we found no differences. I bought or borrowed several "boutique" cables of the era (mid 80's) and found when I heard a difference it was negative and when said cables were measured, they had very high inductances or capacitance. I have not changed them much.
Here is a newer discussion from a former Belden engineer. I encourage everyone to wade through the obvious self back patting ( probably well deserved) in what can be done as apposed to what can be heard, to get to the digital parts.
As it is You-Tube, you have to search for it.
Interview with Glen Gareis on the Intellectual People Podcast channel titled "Do Audio Cables Matter" Almost 2 hours but worthwhile. Glen is the real deal.
If you believe that extraordinary measurements matter, then through a secondary Blue Jeans WEB, you can buy such cables.
The only surprise I had not dealt with was problems on very short Ethernet with ringback. But as my TV has no sparkles, pixilation's, stutter, or any other artifact when streaming HD, I don't have that probem and it is not hard to understand the trivial BW needed for audio is also not a problem. OK,. if a Gig-E network has crap cables and it handshakes down to 10M, so what? I just ran a test and am betting 360Mbs. Great as I only pay for 250. My dime store plain old Cat-5 is just fine thank you. Bonded CAT-5 has a typical error rate of 10 to the -13 so not over burdening the stack in error correction. I did have a lot of problems with HDMI cables which I have discussed before. ( incorrect connections, incorrect shielding etc) My conclusion is to pay the price for Blue Jeans or Belden and be done with it.
I also looked at some other "making" videos. Although the Cardas RCAs may have a pretty good 75 Ohm impedance, I do not like the crimp and friction fit on the pin from my long term issues experience in Failure Analysis. When RCAs were invented ( for HF by the way) the center was soldered inside the pin and the shield soldered all the way around the outer shell as opposed to an extended tab. Things like that matter at 50 MHz. Not at 5Khz.
After thinking about this presentation, think about a few other things. Your speaker can't produce RF and you can't hear it if it did.
Most low level outputs feed through a small resistor. If an op-amp, typically 10 Ohms. So, what does a few mili-Ohms do to that? Look at the input RF filter on the next stage. Yea, a CAPASITOR! Higher than the cables. What is inside your speaker? BIG inductors and capacitors. What does the output Zobel in your amp look like? OK. Just because you can measure something by it's self does not mean it has any impact to how it performs in a system. Think, then spend whatever makes you happy as it is what your brain invents is what you hear, not the actual pressure waves.