Originally Posted by mojo
Slew rates on those scales for audio apps are meaningless. Typical line level output from a CD player or DAC is 3V peek to peek. That means that the "regular" cable could do a full peek-to-peek swing in 0.1us, or 1/10,000,000th of a second, or 10MHz. 10MHz is a bit beyond what most speakers can reproduce. So even if you played that square wave, the extreme possible example, the movement of the speaker cones would be the same with every cable. They just can't move that fast, in fact a tweeter that can go up to 44100Hz is 266 times slower.
We manufacture digital cables as well as analog and for that application it definitely is important to have slew rate as high as possible, as to the rest, you can hear the difference in resolution. It's about reproducing the micro details of the wave, which requires a very high slew rate response. There any improvement is relevant, even at very short timescales.
If you want to argue audibility, go ahead. You won't get a very good argument going from me because I have heard the difference.
-Brad