I don't think you've been reading, but I understand. It's all a little dry. It is understood that extraneous variables must be removed. But does the knowledge/belief that there is no difference before test count? In fact, knowing that they're testing for differences in cables sets up all sorts of biases in people's minds. Some will try to look for things that might not exist, while others may become blind to whatever might be there. Other factors such as those others that I have mentioned must also be considered and dealt with properly also. My general reservations include the fact that the finer points of our hobby is a bit of an acquired taste and requires developed senses and some are more acute at picking up these things than others. This can play a big factor on results. For example, if one expects a bunch of people to be the indicator to whether cables make a difference, do we know if the same group of people would agree on another test in the same environment but with changes that are actually more pronounced and deliberate? To me it's like measuring something without first calibrating your measuring equipment. Anyway...
It's already been stated that you cannot prove the null hypothesis. However cable enthusiasts and sellers who claim to be able to hear an obvious difference should be able to tell in a DBT. Unless they're being fooled by placebo. It is only common sense to treat these claims with suspicion, let alone spend a thousand dollars on them.
And I was under the impression that a lot of people are saying that cables have no effect as long as they are functional. (We ARE including wire hangers, after all.) So they do have an effect on the sq now? That's good to hear, thank you.
The 'simple' answer is 'no, there is no difference'. However a simplification is by definition different to the truth.
0.5dB difference is in audible? It's not all that far below audibility. http://www.audiocheck.net/blindtests_level.php?lvl=0.5 some people can go better than that. It's amazing.
A 0.5dB absolute level difference, perhaps. But what we're dealing with here is something like 0.2dB down at 10kHz, and 0.5dB down at 20 kHz. I can't even hear at 20 khz anymore,
I don't think I've said anywhere that cost=performance. It's an interesting result, nonetheless. It sort of shows that that particular $2/meter cable sounds "better" than the 'audiophile cable'. So if we call the $2/m cable an audiophile cable, would that change things? The point here is whether or not cables can make a system sound different or not (i'm refraining from 'better' here). The $2/m cable seems to say that it does.
Better is subjective. That cable has less distortion, but the amount is insignificant for most cable lengths.
So at the magic 3 m, it somehow matters. As I do not see anything intrinsically magical about the number 3, i assume the same factors whatever they are that matter at 3 m remain important at 10, 19 or 1 meter, correct? May be at a lower magnitude but still there, may be? This kindda goes against the "all cables are the same and if you think they're different you're imagining things" posts I've been reading.
You know, I'm sort of with you on this one, though. Between my gungnir and mjolnir I use the schitt cables at 6" and I can't think of anything that will better them cos 6" of decent cabling should at least do less damage (if it does at all, granted) than anything 1 m long, no matter how amazing. So up to a point, if you go extremely short, things probably don't matter. I think there's a wireworld youtube clip where the guy talks about this. But I don't think this discussion has any limits on length however.
Obviously it depends on the length of the cable. Those posts are simplifications designed to prevent clueless people from spending huge amounts on cables without reason. Of course if someone wants the full explanation, nobody here is going to stop them.
You seem to have respect for proper engineering of things and so do I. Given that, I'm sure you also know that there is no such thing as "the best" design in engineering. That $2/m cable I'm sure can be made better too. If the task is taken up by someone who works for a company that makes audio cables and he/she ends up improving on it and sells it for $20/m, would that be somehow a scientific impossibility suddenly?
Better cables already exist. The point here is that nobody needs to pay more for a cable that delivers an improvement below the threshold of audibility.
Finally, I included the second link to which you refer as an example of how a dbx test may not be so successful at times. Or at least sometimes results are not entirely reliable.
Not all experiments will be well designed, this is real life. Just look in a scientific journal. However, the more effective the blinding is, the better the experiment. This is why we have things like peer review, clear reporting of methodology and data, etc. Sadly some 'research' has none of these.