Does raising speaker cables off the floor really make a big difference?

Carpets are often made of one of those "fancy" dielectrics, i.e. polypropylene, and polyethylene, and because it is a open weave, would be similar to foamed polyethylene and foamed polypropylene, which are the best dielectrics for cable w.r.t. low dielectric constant, even better than teflon which is difficult to foam. Teflon is used for high frequency cables because it is dimensionally stable which is necessary for high frequency operation (constant impedance).  Wood is a so-so dielectric. Of course a worse dielectric than wood and much worse than carpet would be porcelain what those cable insulators are typically made of.

I have to say this thread is almost like beers but not quite though :-)

Actually, putting a drumkit on a riser drastically effects it’s sound, and some recording studios do so for that very reason. But not as much so as where in relation to the walls the kit is placed. Avoid at all costs cinderblock walls, as I learned at one studio in North Hollywood. Too close to one made the sound all "phasey" (think "Itchycoo Park"). Out as far as possible into the room is a good rule of thumb.

Interesting timing. 

I'm of the mind it really isn't going to change things in the slightest. But, I'm game to see. 

I ordered a set of fuses and when I got the invoice it said congratulations we're sending you a free set of cable risers for free.

Box is delayed somewhere between here and Philly so gonna have to wait longer to hear for myself. 

Wondering if my box would have been ontime if it was raised off the floor of the truck? 

I have found that any sonic benefit of raising the cables is negated by the irritating noise made by the mice feet when they do the limbo under the cables.