Recently found this video:
Apologies if it has already been discussed before, but I still have a few questions.
Now, a disclaimer, after learning about null testing, I am confident a passive cable, regardless of marketing, sounds the same as any other cheap cable with the same physical specs in terms of length and girth. In other words capacitance and resistance, and most cases these difference are too small to matter even if it is measurable, so cables sounds the same.
The video is ABing between 2 cables, $120 and $4800. The AB testing done in this video by Jay yielded mostly random results, insignificant as he says, so we can ignore those, but in his testing, he guessed correctly which one is which 9 times in a row, which is very impressive (14 minute mark). My calculation for the probability of that happening per chance is 1/512, or 0.1953%.
Which begs the question, was he just lucky or do the cables actually have a difference.
Now, I did not see him mention anywhere the specs of the expensive cable, e.g. if it is passive or active and its size. Secondly, the AB testing he is doing here with guaranteed switching can and will induce a bias in which the listener will be forced to find a difference since he knows it has been switched for certain.
Can someone help me out here? My guess is that he used an active cable.
First let me admit that I sort of skimmed the video.... I did watch all of it... but not all carefully.
First - I agree with you entirely - there is no reason for "a more expensive cable" to be able to do ANYTHING better than a cheap cable in terms of actually transmitting the signal to the speaker. There may be a few amplifiers out there that are very sensitive to RF interference picked up by the speaker cables - in which case a shielded speaker cable might help. But there are also a few amplifiers that are sensitive to capacitance - and those few may have problems with the extra capacitance in a shielded cable. It is worth mentioning that some expensive cables DO have really odd electrical characteristics which may cause some amplifiers to act oddly... and could cause the audio to sound different... but, if so, they are ALTERING THE SIGNAL, and not "carrying it better".
Also, as far as I know, there is no such thing as an "active speaker cable". (Putting a DC bias on the insulation, or an outer shield, serves no technical purpose at audio frequencies, and does NOT make the cable itself "active".)
Second - If ANYONE heard ANY difference in an online test then it was due to something external. Just look at the signal path: Original amplifier, to speaker cable, to speaker, to microphone, to analog-to-digital converter, to a digital file, to playing that file back on a DAC, going to an amplifier, going to another speaker cable, going to another speaker. There are MANY places in that signal path that are almost certain to produce differences far more significant than those we're testing for... so, even if there was some real subtle difference in that original speaker cable, it would be entirely obscured by those other differences. (To put that differently any difference in the original speaker cables would have to be huge to make it through all that other gear.)
Now... there are lots of ways in which people can be biased to prefer one thing over another when there is no actual difference. There are obvious things, like hearing switching noises, or the tone of voice of the person asking the questions, or waiting to see what others pick. There are also more subtle things like the order in which things are listed. In taste tests of foods people will often consistently choose "the brighter one", or "the one on the right", or the first one they taste. With music, we tend to hear more details after hearing a track multiple times, which may make later runs sound better or worse (depending on whether we notice more good details or more flaws).
And, finally, they did mention that they are using Class-D amplifiers. As a broad generalization Class D amplifiers tend to be more sensitive to the electrical characteristics of their load, which includes the speaker cables. Therefore it is not impossible that a Class-D amp might sound different with speaker cables having different capacitance. Note that this would NOT mean that one was better, and it would simply be random what sort of difference would be heard with different amplifiers and different cables.
I also didn't really look at his methodology....
For example, even though he didn't tell the listeners which was which, did he say "here's cable A" and now "here's cable B"?
The proper way to do this is to have each listener listen to a whole bunch of trials...
Not knowing which cable they are listening to each time...
And not specifically switching each time (each trial is independently random)
Have them write down their results...
Then tally them later...
This avoids certain known problematic psychological effects.....
For example, even if I don't know which cable it is, once I say "I think that Cable #1 has a wider sound stage" ....
I am biased to actually HEAR a wider sound stage the next time I listen to Cable #1 ...
(And that effect is magnified if I say so - to other people - and especially if I say it out loud - to people I know.)
The way to avoid this is to have me listen to 20 trials - not tell me which cable I'm hearing each time - and tally the results.
And do the same with the other test subjects.
(I should also be instructed to write down my results - and NOT share them with the other listeners - until done.)
(In fact - we should be isolated- so we cannot see each other smile or frown during a particular trial.)
In short his test seemed quite informal....
(Which he did admit several times.)
