You will never see double-blind testing done for any "high-end" audio equipment, especially the cabling. It would show up the bullsh*t for what it is.
Actually, 20 or so years ago, one of the audio magazines actually DID a double-blind audition of Monster Cable, zip cord, and a couple of other choices of speaker wire. Once wire gage went above, IIRC, 18 gage, nobody could hear a difference.
Nobody.Now, it makes sense to have good connectors, but as for the wire itself . . . I bought 12 gage speaker wire from Builder's Square (used to be part of the K-Mart chain) for 13 cents a foot during a half-price sale, and soldered on some decent connectors from a local electronics store. It's still working fine, and the wires haven't worn out from all the electrons passing through.
BTW, you DO realize that the large diameter transparent insulation on Monster speaker wire serves to magnify the image of the wire, making it look bigger than it really is, right?
As far as interconnects go . . . it makes sense to spend a
few dollars to upgrade, as the thin-gage stuff the component manufacturers put in the box is prone to failure, kinking, and corrosion/oxidation on the connectors. But if someone tries to sell you a meter long interconnect for hundreds of dollars, the salesman must be thinking you have the word "SUCKER" written on your forehead.
(Applies to video cables, too . . . even on the AV forums, people have caught on that buying a short HDMI cable from Best Buy for $140 is idiocy, when you can get competely functional cables from Amazon.com or monoprice.com for a small fraction of the price.)
