How much space between cables is enough?

Rubber bands not the only thing that rots.

tony1954, Don’t try to understand or debate millercarbon. He is a tweaker supreme and is certain that his way of doing things is the only way. If you don’t buy less expensive gear and tweak the hell out of it, you are stupid in his world. All tweaks cause mind blowing improvements in sound. Trying to make sense of what he does will get you nowhere. If you want to know where he’s coming from read the Tekton Design Moab thread.

I wish I had a good answer for your original question, but I don’t. I try to avoid obvious problems like speaker cables running next to a power cable, but don’t get too deep into cable separation.

@tomcy6
I am old enough to know that I don't agree 100% with anyone. That being said,there are a lot of people out there that know more about certain things than I do. My job is to listen to what they have to say, digest the information and then separate the wheat from the chaff.However, one consideration that concerns me is whether my "ear" is good enough to benefit from the advice.Only time will tell.

The power cables will create the strongest electromagnetic interference and the speaker cables will be the least affected.     Your interconnects will be creating the least EMI (carrying low voltages and current), and the most sensitive to interference, as all are feeding a gain stage, of some sort.     If you’re an SPL lover; speaker cables might create a little more.     If you can keep a couple inches between, not parallel cables over long runs, and/or cross power cables, at 90 Degrees with anything else: you’re sweat-free.       ".........but don’t get too deep into cable separation." +1        https://www.prosoundtraining.com/2010/03/15/the-emi-project-part-1-introduction/

But doesn't that make the material and design of the elevator somewhat irrelevant? The principle focus is to have the cable suspended by the rubber band.

We don't know that to be the case. Not for sure anyway. When I first tried this many years ago anything that raised cables up off the floor was an improvement. Cable Elevators were by far the best. Cable Elevators are ceramic insulators, designed specifically to prevent electric charges migrating along the surface and since they worked the best it seemed logical to assume it had something to do with insulating from static or electric charges. 

But then I tried a thin coat of Total Contact on them and that was remarkably better. TC is extremely conductive. So there goes the insulation theory. Several very credible people say suspending on fishing line from the ceiling is even better. One of them I asked, what if you use fishing line to suspend them from a sort of trellis? Not as good. Why? Don't know. Tried it, not as good. You have to hang em from the ceiling.

Now I'll do a lot for sound but having to weave around a bunch of wires like Tom Cruise on a Mission Impossible that's where I draw the line. 

But I keep thinking about it. Why? What is different about fishing line hung 8 feet from the ceiling vs fishing line hung a few inches? Well fishing line is sort of elastic. It stretches. But not very much. Its not very springy over a short distance, but over a long one it is. Maybe that's what's going on. Its acting like a spring. 

Well a rubber band is basically a spring. Stretched over the Cable Elevator it suspends the cable like a spring. But its also close enough to still get whatever effect there is from TC. Which believe me, there is. 

So it would seem we have our answer. Its vibration control. Suspending cables in a way that allows their free movement without picking up vibrations from the room is a big improvement. Insulation may have something to do with it but the biggest difference would seem to be due to vibration control.

We're still not sure but a lot of evidence sure seems to be pointing this direction. Still, you never know until you try.