How much space between cables is enough?

I understand that proximity between power cables and interconnects or power cables and power cables is a problem, but is there a rule of thumb as to how much space is required to NOT be a problem. 1/2", 1", 6"? Also, are all cables the same? I would assume that the higher the current, the more isolation, but belief and reality are seldom the same.
No rule, not the same- and belief and reality, depends on who we are talking about. There's way more going on here than space. Check out my system. A long gradual process of trial and error going on there. Those cables are routed the way they are because it keeps them at a good distance, from each other and components, keeps them off the floor, and suspends them where they are largely free of floor-borne vibrations. 

The last picture in my system pics is a close-up of the most recent thing I have learned, that cables sound a whole lot better when suspended in free air. Having them away from each other reduces electrical interference. This is critical with phono leads, important with interconnects, somewhat important with power cords and speaker cables. Keep at least a few inches space around them, and where they must come close its better to be at right angles than parallel. 

Aside from phono leads, with line level interconnects, power cords and speaker cables the biggest improvement by far is the rubber band trick shown in my system. Elevating them off the floor is second. Interference runs a distant third. It may make more of a difference if yours are all tangled in a mess but if they are already fairly far apart then dressing them a little better won't do much. Rubber bands however, different story.
No offense to your photography skills, but I can't tell what is going on in the last picture. All I see is the cardboard "tunnels". Is the idea to have the cable supported solely by the rubber band? Like a small hammock?
Cable art, I got pretty good at it...  then BUMP it! like dominoes. Then there's one kinda tweaked, way the heck in the back of some place.

Mine looked like crop circles at the bass bins.. LOL, coiling XLRs or RCAs. My dog is an acrobat, never touches a thing, good girl.

I been thinking on MC cradle suspension, I'd need a few and rubber bands rot. Need something with a longer life, I think. I've seen clear zip ties, last 30 years, out of the sun. Beed, ladder, flat or round, zip ties might be an ART option, also... They are called Cooler ties, round stock with round cleated locks.

Cable Elevators are ceramic insulators commonly used on telephone poles. The top has a cradle or saddle shape with the cable normally laying in the saddle. Yellow rubber bands are stretched across this saddle. The rubber band stretches and supports the cable just above the saddle. There's not a lot of space, but if you look at the earlier photos you can see the cable is resting down more in the saddle. They don't have free range to bounce like the speakers but the bands do hold the cable away from the elevator leaving it free to vibrate on its own. 

The cardboard tunnels are PPT eMats cut and shaped into tubes and painted with Taytrow TDF.
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.
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.
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
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. 

+1 @rodman99999 

Power cables can run in parallel, closely, and should cross everything at 90 degrees. If you must coil power cables, do it far from everything else, and make the circles as big as possible.

Speaker cables should cross interconnects at 90 degrees.

Interconnects can run in parallel, closely, if they are shielded, like co-ax.

Closely ~ 1".  More than that is diminishing returns, IMO.

Interesting, I wonder what effect suspending cables from weak springs or 'floating" them on 6" inner tubes would have.
Interesting, I wonder what effect suspending cables from weak springs or 'floating" them on 6" inner tubes would have.

Try it and let us know.
Tony, I suggest that you stick with the physics until you have 6 figures invested. Physics suggests that putting anything ferromagnetic, like a spring, close to a signal line is a bad idea.
Researching the idea of suspending cables I came across a post on another site about using rebar chairs for this.  They come in different sizes and look like they would enable the rubber band trick.  Cheap hack if you think it would work.  Personally I doubt I could hear the difference but if I ever get things settled down enough that I'm not always moving stuff around I might give it a try.

And rather than buying incredibly expensive audiophile vibration isolation gadgets I would love to know why these guys wouldn't work almost as well:
@pinwa, good calls imho....

The r-bar chairs could be hot glued onto a strip of wood, spray the thing to match the floor.  Fab spaced as needed, spaced as desired...

Cheap seats.....pardon d pun....;)

Better:  EVA 'twist chair & wood....*S*  EVA under makes it non-slippish...

The suggest EVA would work & look nice, but that's lotsa $ for a ribby tiny thing.  Instead....

Get EVA where I do....

This page has the thicker sheets; there's thinner available, and others in different densities. Glues, cutting things, all that....

What's left over you can make into your audioholic that tinfoil ones y'all seem to be drawn to....*smirk*

If you must cheap out, they have seconds'....
I would love to know why these guys wouldn't work almost as well:

A very common mistake. Why does why matter? What matters is if. Not why. If. You can go round and round to infinity fantasizing about why. Or you can get spend five bucks and in five minutes listen and know. One way you find out. Other way you never know.

Choose wisely.

And when you find out, let us know.
If I thought I could hear the difference, I might be willing to spend the hundreds to thousands of dollars on the fancy vibration isolation gizmos but I'm pretty sure I wouldn't.  I will say that putting those  E.V.A. Anti-Vibration Pad's under my subwoofer improved its sound immensely.  Instead of the booming rumbling unmusical beast it was, it became tight and a pleasing companion to my Magnepan 1.7's.  But putting those same pads under the 1.7's deadened the sound.  It makes sense that tube amplifiers should have vibration isolation so I have them under that too.  So I agree, listen and you may know, but some of us operate with more of a budget constraining our options.  I'm getting the Tekton Moabs in 5-6 weeks and it will be interesting to try the EVA pads under them.  Probably they will deaden the cabinet so I'm thinking of having a board or granite slab resting on them and the Moabs on top of that on spikes.  That is a more realistic option for me than throwing $600 at the  Isoacoustics Gaia II Speaker Isolation footers.
@millercarbon telling us how great his system is again. He is a broken record. Oh! and look at the photos. He's so proud, he wants everybody to know how cool he is.
The EVAs are similar to AV Room Service's EVPs. know these work. Also recommended by Jim Smith (Get Better Sound).
The only way to take the floor completely out of the equation is to suspend from the ceiling.  The gauge of the monofilament should de commensurate with the weight of the cable.
What if the ceiling is also the first or second story floor?
What stops the vibrations being created by way of walking around or mechanical vibrations from translating itself down the fishing line thereby vibrating your cables?
Eye hooks --> rubber band --> monofilament --> cable.
Should have been more explicit.
Always run the positive wire on your speaker cables on the right side of you room, and the negative side on the left of the room.  Then, run the power cord from your front porch outlet, around your garage and coil it 7 times around your water heater tank.
Proximity of "Power cables and power cables is a problem". Huh? That makes no sense as they are energized identically and who cares after the 120v reaches the power supplies and becomes DC. I would keep signal cables away from power cables in any situation; audio, video, computers, anywhere.
@millercarbon telling us how great his system is again. He is a broken record. Oh! and look at the photos. He's so proud, he wants everybody to know how cool he is.

Well let's see now.... its been two full days since I mentioned the rubber band tweak, and how well it works, with even a photo showing how-to. All it takes is a few rubber bands. Can't take more than 5 minutes beginning to end. 

So tell us tuberollin, how did it go? When you tried it? Oh, what's that? You didn't? So you really have no idea what you're talking about then, do you? Because that is but one of a very, very long list of improvements, the vast majority of which most around here are just like you, blather blather blather but never bother. Never bother to try.

So I am not only fine and happy but proud of what I have accomplished. And yes it does sound fantastic. Can't say it often enough, because its true- and because I keep making it better and better.

People really should study it. There's a lot there to learn. For those who want to walk the walk. For you, something tells me its talk the talk.

(Oh now this is delicious. When I first type tuberollin the sites spell-check tries to change it to tuberculin. Heh. Good one.)
I tried the rubber band thing for about a decade.  I stopped using it, but later found out my cables were probably picking up ripples in space/time from merging neutron stars and black holes.  Yeah, this was before LIGO.  My system was way too analytical back then.
My AES3,  ethernet and power cable all run down one of the legs on my speakers stands. They are hidden in the back attached with velcro and are about a couple of millimeters apart. Once they get to the floor they are all together velcroed then they separate at the rack, power to the surge power conditioner,  ethernet to my netgear switch and AES3 to the streamer. My cables are either touching or within a few millimeters. 
Do people really want to be in the room with cables floating in the air hanging on fishing lines?

"Do I coil it around the water tank clockwise or counter clockwise?"

It will heavily depend on the side of the water tank you will be doing it from.
What's left of my brain hurts!
Keep wires from touching as much as possible (within reason) and enjoy MUSIC!
Glupson is touching on how I feel about it. Not only would I not like to stare at fishing lines holding cables across my listening room (I apologize but I was being sarcastic about the fishing line weight), but I would also dislike looking at wires the size of water hoses laying across the floor everywhere on top of ceramic or whatever supports. Just me, but my listening experience is a balance between the sound and the visual. If it looks like a mess, I will feel like a mess. If it looks good, I will feel good even if I don't get that top few percentage point in sound quality. To each is own. 
tony1954If you coil the interconnects clockwise around the water heater, you must coil the speaker wires counter clockwise, assuming that the power cord has the left prong in space time alignment with the rotation of thh Earth, at least during eclipses.
Thanks guys. I like touching minds.

Once we start talking about cable elevators of all sorts, such rooms look boobytrapped to me.
Do people really want to be in the room with cables floating in the air hanging on fishing lines?
It makes vacuuming so much easier...

"It makes vacuuming so much easier..."

"Hmmm, what is that in that ceiling corner? Spider web or my speaker cables? I'd better be careful when cleaning."

I coil mine around the water heater much differently.  I go from top to bottom, and it must be a minimum of three wraps.  Phenomenal difference!  Enlightening to the Nth degree.  

Though I am kidding, of course, somebody might actually try this.  Oh, what have I done?

 Honestly though, have a good time and just maintain logic, i.e., don't run the power cables close to and/or in parallel to any signal cables.  By all means, enjoy the music.