" Here's what I've found in over 40 years of listening...
1. Cables (and AC cords) DEFINITELY make a difference.
2. Interconnects cannot 'improve' sound. All they can do is degrade it. The best ones degrade the sound the least (i.e. they transmit it with the least 'damage' and 'loss' of the signal).
3. Generally, these differences are MORE pronounced w/ better (i.e. more highly resolving) components. If the signal is distorted to start with, a great cable will only give a more accurate presentation of that distorted signal. It cannot 'clean it up'.
4. Lastly, to those who say 'if you can't measure it, you can't hear it'... You're assuming that we can measure everything that matters; that our knowledge of electronics, physics, and psycho-acoustics are all perfect. Absurd! If you think there's nothing left to learn... well, that's extremely foolish, isn't it?"
If you've been listening and evaluating for 40 years and didn't know that one of the primary problems with interconnects is common mode noise, then pretty much everything else you have to say on this subject is useless. It took the "audiophile community" about 25 years to acknowledge what the "objectivists" in the pro sound community have been saying all along - BALANCED LINE LEVEL CABLES ARE REQUIRED FOR HIGH FIDELITY. Finally, after many, many years - "high end" components are more often than not using balanced inputs. The problem with interconnects isn't signal loss as aalenik proclaims above - it has always been picking up stray low level interence from adjacent power cords and rf - the longer the run the more chance for very low level electromagnetic radiation to get picked up in the interconnect and passed along to the input stage of an amp where it is magnified greatly.
As for aalenik, there are very good reasons not to put your faith totally in the subjective camp or objective camp. Principal among them would be that the person inclined to do either is likely clueless. An open mind and intelligence requires that we respect both our direct audible senses and all the evidence our other senses can bring to bear to help us learn about that which we do not know. We measure. We listen. And we never stop trying to draw correlations between the two. When we do - we have disavowed the pursuit of "truth" in favor of "belief" and all scientific progress comes to a grinding halt.