Best way to hear sonic signature of a cable?

A better way is to blindfold yourself and have someone else switch the cables
and see if you can even tell which is which. If you can't, then don't buy the
hype. If the more expensive happens to sound like crap, keep the cheaper
one. Lather, rinse, repeat. Next, take all of the money you were going to
spend on expensive cables and go out and listen to more expensive speakers.
See what kind of speaker upgrade you could get with that money. Ask
yourself which is the larger bang for the buck upgrade. Listen to the different
speakers with your eyes closed or have someone else switch between them --
see if it is as hard to tell the difference between speakers as it is to hear the
difference between cables [while blindfolded]. Ask yourself if you'd rather
have better speakers with inexpensive, but well-performing cables or the
same speakers but with more expensive cables. These are the tests I would
suggest.

Actually, I think Newbee is correct.

When you've run your rig a week with the cable you're evaluating, then swap back to your old cable you instantly "feel" the results.

Do you connect with the music better, or do you instantly feel a loss of involvement? This is what works for me anyway.

I've learned that what seems "better" is often just "different"...this is why cable evaluation takes patience.

try to listen on the most efficient set of speakers possible- you will hear more of the differences...

"try to listen on the most efficient set of speakers possible- you will hear more of the differences..."

This is not always true. One can argue that high efficient speakers has lower requirement. Therefore, you can't hear as bigger difference because it doesn't draw as much current/voltage through the cable. I found the less efficient setups can hear the same amount of differences too. It really depends on your overall setup.

Consistency is the key to test the sonic signature. It doesn't matter how many setups you test, you should always get identical results.

I've always compared any cable over 5 totally different setups and found the result always identical.

The old/new/old drill many of the posters mention is something I apply to all equipment, not just cables. I am doing that right now with two different amps.

In general, I listen to each component switch for about a week. And I weigh both the immediate difference I hear when making the switch and the long term feel I get for each component as I spend time with it. The reason I spend time with it is so that I can listen to a broad range of my favorite and familiar music. I've also found that certain gear needs a little more time than others to re-settle in with the system.

I realize the way I conduct my test includes many other components in the chain, which could influence my overall impression. If you're trying to get a feel for the character for a cable by isolating it the best you can, your method may be optimal.