Cable elevators

In ground wire radials on antennas, raising the wire off the earth ground will actually change the characteristics of the antenna, ergo the wire.  What electrical change, I don't know and have never measured the actual wire.  I do know it affects SWR.

How that translates to speaker cable, I'm not sure but under certain conditions I wouldn't doubt it affects sound, especially in longer runs.

I think it depends heavily on the construction and shielding in the cables. I couldn’t tell anything different with my AQ cables with DBS. But with tiny and thin Mapleshade cables with virtually no shielding by design, it makes sense to get them off the floor. 

There are some ridiculously expensive cable risers out there. I made my own from some scrap butcher block that I used for my shelving. It was a fun project and they look great. Do they make a difference? If they do it is very small but it did get my cables off the floor and easier to dust....!

Joe from Kubala Sosna says let them sit on the floor.  I agree with @jallan , depends on cable design.

Impress your friends. Use Champaign goblets.  Glass is an even better and more consistent dielectric. Just don't admit they came from Ikea for $12 a 6-pack as of course, they can't sound as good as Waterloo crystal.  :) 

In reality, if you believe they sound better, it is your enjoyment that matters.  In the world where physics still rules, maybe if you were on a steel raised floor ( computer room) and ran hundreds of feet, with too-thin insulation, OK, maybe it does not violate any laws.    Full disclosure: I run 12 gauge twisted pair with pretty thick vinyl insulation. Only about 8 feet.  I have heard differences, but only in fancy cables screwing up. Shielded cables for instance have much higher capacitance and in a long run can, can, roll off the top end. Maybe.   Twisted Zip cord is near perfect for speaker cables. Funny, the original Monster cable was actually very good. 11 gauge, twisted, thick insulation. 

Yes, at RF frequencies, a lot matters. Speakers do not respond to RF. SWR in a speaker, ( fractional Ohms into several) also do not matter in AF.*  Do not fall for salesmanship that take valid physics from a different a domain and try to apply it to audio. 

There is a HUGE amount of money that can be spent that actually damages the sound less in speakers, amplifiers, DACs, and of course the room than thinking magic tweaks will help. I really want to hear an Aries II in my system to see if it is any smoother than the Atom+ as far as female vocal sibilance.  So far, no one has beat it. ( thanks Amazon returns) Clear, audible, repeatable differences. 

* I had an odd case. Amp had no RF filter in the output. No Zobel.  Long cables. A yahoo with a 1000W CB radio in his truck blew my tweeters as the RF was picked up by the cables, detected by the amp feedback and amplified. A set of Kimber cables made it sufficiently immune.  Then I solved the root of the problem when I identified the truck.  A strait pin can do wonders when pressed through a coax. So, defective amp design, illegal transmitter and a real problem.  Hack ( cable) mitigated until I fixed both root problems with a better amp and "fixed" his footwarmer. The good outcome was the Seas tweeters I used to replace the T-2000's were much nicer.