Speedskater

CD players! end of story.

Power cord and hum : maybe. Speaker cable and amp instability : maybe. * * * * * * * * * * * * Twisted pair or Quad speaker cables are always a good thing. Twisted power cords are always a good thing.

the Pacific Northwest Section of the Audio Engineering Society has a ton of great papers and Power Points: http://www.aes.org/sections/pnw/ by j.j. (James D. Johnston) http://www.aes.org/sections/pnw/jj.htm by other experts: http://www.aes-media.org/sections/pnw/ppt/

Why do automobile magazines measure dozens of parameters (and to a level of precision) that won't matter to the readers of the magazine, thinking about getting a new car?

From reading Henry Ott, my take is zero distance is best.

any AC power line filter should be placed as close to the component that it's powering as practicable.

Well designed equipment should not be sensitive to external AC to DC supply's. But when we talk about audiophile equipment, it's a different ballgame. But any differences will show up in the measured Signal-to-Noise ratio at the component's audio output. This needs to be a wide band measurement, best done with a battery powered meter. Also an O-scope check for high frequency noise.

It will come down to the skill level's of the design engineers involved. An 'active crossover' has a lot more parameters to mess up. It happens often with DIY 'active crossovers' they look at the specs for their speakers and put those numbers in, but what comes out is not the same as the original design.

Actually that cable is optimized for much, much higher frequencies (like 12 gigahertz) than digital S/PDIF audio. Better to chose a coax optimized for 1 to 20 megahertz range. Like Belden 1694A, 1505F or 1695A.

An excellent 1 meter BNC digital cable will cost about $25. One wonders about why there is a market for lesser cables at inflated prices?

While it's true that the BNC is a much better connector design, how many audiophile components have BNC chassis connectors.

For S/PDIF there is no electrical difference between RCA and BNC connectors. The digital audio frequencies are way to low to be bothered by connectors. This connector business is just another audiophile misunderstanding.

The minimum digital cable length thing is just another audiophile misunderstanding. Some great US suppliers: https://www.markertek.com/ https://www.redco.com/ https://www.bluejeanscable.com/store/digital-audio/index.htm

As far as DIY speaker cables go, those are an amazingly low value.

It's interesting that the link in post #2 does a good job of describing each plating material and then quickly jumps to some alternate reality about the sound of each material.