Why are digital streaming equipment manufacturers refusing to answer me?

Jmphotography, in the system you describe there is no fiber optic blocking all noise and as a result I completely understand that there could be improvement with a good streamer. Thank you for that feedback.

Given the light discussion around ab(x) testing, as a scientist with phd training in human data collection and cognitive functioning, I object to the (x) part of the judgment task.

Identification should not be the goal. We listen to equipment to decide which we prefer... which is better.  That should be the decision when doing (blind) ab testing.

If I were designing the test for audio equipment, I'd let people switch back and forth as many times as they like, taking as long as they like for each (level matched) sample.  Eventually they just decide which they like best. Repeat that task over and over throughout the course of listening to music and I guarantee that people will begin to find their true preference and that that preference will be consistent. 

It's very easy for the brain to develop and make decisions based on good/bad/preference and much harder to make the decision based on label identification. They are different processes in the brain and preference is the more basic, a primary system. Newborns know what they like and what they don't and will often show good a/b consistency. The brain doesn't even need to identify a stimulus to make this judgment. That comes later because it's less important. First, figure out if something's good or bad, then if you've got time, figure out what it is.  This is the order of processing for all of us.

The eye doctor uses this ab-preference testing when they're figuring out your prescription. They flip between two possible magnification factors and you just tell them which is better. It works great for letting you find your own way to an optimal solution. They don't care about labels or giving you mystery options and having you say whether it corresponds to a or b because that's irrelevant. It would make the process less effective. 

And finally, I'll just say that if you don't believe in blind testing, you're lying to yourself. There's decades of research demonstrating the impossibility of avoiding the biasing effects of pre-existing knowledge. People have used samples of scientists trained in this area of research and they are just as influenced as you or I. You are not immune.

That said, it's hard as hell to do blind testing and I never do. Fortunately placebo effects are very real and they help your preconceived decisions feel right even if they were wrong.

If you were a PhD with said qualifications, you would know the X has nothing to do with identification, it is to test reliability. If you can't match A or B to X, then you can't tell the two apart and you hence have no preference as you don't as actually prefer either.

Given the light discussion around ab(x) testing, as a scientist with phd training in human data collection and cognitive functioning, I object to the (x) part of the judgment task.

Identification should not be the goal. We listen to equipment to decide which we prefer... which is better. That should be the decision when doing (blind) ab testing.

Please tell me how matching is different than identification.

And please see above for a discussion of why the brain is better at determining preference than identification.

https://scholar.google.com/citations?user=NQGcNPQAAAAJ&hl=en

Again, you obviously don’t understand ABX testing which is NOT about absolute identification, i.e. picking out the 98 Bordeaux from the 96 and the 99, it’s about having 3 bottles, two 98, and one 96 and being able to tell the two 98 are the same. If you can’t tell a 96 and 98 apart then you don’t actually prefer one over the other. ABx increases the statistical reliability of an AB test. ABx testing IS a preference test essentially as it requires no absolute identification.