Having started this thread, I will weigh in with a comment. First, I can't understand how Judit can flatly say that DBT "serves no useful purpose." I DBT'd cables using a Marantz 8300 DVD-A/SACD/CD player (this has two L/R outs so cables can be directly compared back to back, and also has coax and optical digital outs to compare those). The result was that by keeping everything else in the system constant, we were able to listen for differences between the IC's we compared (Audioquest Python vs. Tributaries SCA 150 and Nordost Red Dawns). We were also able to identify the sonic characteristics of each cable. Some of the differences between the Pythons and the Red Dawns were subtle, but readily identifiable. I found the ability to DBT invaluable. I then put both cables into my system for a while to get a "feel" for each over time and many different LP's and CD's. I certainly don't say that DBT is the be-all and end-all of decision-making, but it is difficult to say that it serves no useful purpose. I am waiting to DBT cables several steps up from the Pythons and see what a huge expense in $$ buys in identifiable differences! I think Redkiwi is also correct in saying that sonic differences do not necessarily translate to more musical enjoyment.
Why is Double Blind Testing Controversial?
I noticed that the concept of "double blind testing" of cables is a controversial topic. Why? A/B switching seems like the only definitive way of determining how one cable compares to another, or any other component such as speakers, for example. While A/B testing (and particularly double blind testing, where you don't know which cable is A or B) does not show the long term listenability of a cable or other component, it does show the specific and immediate differences between the two. It shows the differences, if at all, how slight they are, how important, etc. It seems obvious that without knowing which cable you are listening to, you eliminate bias and preconceived notions as well. So, why is this a controversial notion?