Bud, is Mille' still alive? He designed the MAC 3500 that we used with the Grateful Dead. It is a wonderful power amp. Much better than standard MAC's. We met years ago. The best amp of its kind, that I know about.
No, not at all. As long as the experimenter doesn't know the answer, there can be no Clever Hans effect. Again, you have to postulate some mysterious mind-control causing the participant to suddenly not be able to hear differences when blinded- remember, at the start of the tests with the experimenter present, Tiefenbrun and Lavigne and Zipser agreed that the differences were clearly audible. Apparently, the mind-control was switched off then...
AFAIR you´ve only stated that is wasn´t significant, without any analysis or argument presented.
Regarding technical controls you have to be more specific, because he uses several and even a negative control.
It may be amusing, but in difference to ABX he uses a paired preference test which is much more familiar to the normal user.
It´s intentionally a group test and so it is different compared to a test of a single listener, and he did, according to his description, some preliminary tests and refined the test procedure based on these preliminary tests.
But it is as usual, if a test result is positive one has to look if it was the EUT that made that result or if other reasons were possible.
In contrary, if a test result is negative, one has to look if some confounders prevent the participants from detecting a difference.
Sturm did use a negative control, that was nice to see.
Wishes
It is difficult, to 'impress' SY. Me, I'm easily impressed, I just listen for myself. Sure, a few errors squeak by, one in a while, BUT the overall result is PROGRESS! ;-)
Is that so? If the experimentator thinks that no difference is audible he can´t express that nonverbal?
It wasn´t reported but there is nowhere stated that Tiefenbrunn for example was familiar with ABX tests and of course no positive control was used.
BTW, remember that Lipshitz himself confirmed by his description that no one was reaching the sufficient sensitivity level.
Wishes
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That was the strong point. Unfortunately, there seemed to be very little information on the controls implemented to insure absence of non-auditory cuing. If I'm mistaken about this because of my mediocre German, please point me to the proper sections.
He can even express it verbally. But as long as the subject still claims to hear the differences with the experimenter present (but with non-auditory cues), you have to postulate not just mind-control, but mind-control that can be switched on and off!
That’s a bit unfair for two reasons.
First, as terry j pointed out, dbt for loudspeakers is simply not feasible in a home environment, even if you wanted to do it. You would have to make sure each loudspeaker was placed in its respective “sweet spot” each time you listened. And what if one speaker system was passive and the other active? Imagine the complications in amps and switching. That’s one reason why loudspeaker manufacturers like Harmon Karman built special facilities to mechanically move different speakers during listening tests. In contrast, dbt of cables can be done straightforwardly at home with a person’s own equipment.
Second, there are clear, measurable differences between loudspeakers. And loudspeakers with different designs clearly sound different from each other, in particular in the way they interact with the listening space. It would not be very useful to do a dbt between say a Quad electrostatic and a horn loaded infinite baffle design in order to say “Can we distinguish A from B?”. Of course we can, more or less instantly.
The best use of dbt is, for instance, when engineering theory says a priori the differences should be subtle or non-existent. Then you need dbt to remove the non-audio biases that can come into play so that we can determine if there really is a difference between A and B. That is rarely the case with loudspeakers but is quite germane for cables.
Feasible or not, doing a sighted evalution does only make sense if you think you are able to deal with your bias (at least to a certain degree);
Otherwise if you can´t control your bias, a sighted comparison is pointless as you´ll mostly hear what you want to hear. 🙂
It is not about fairness or not, more to think about the various arguments; if it´s black or white, that any sighted comparison is pointless (Toole/Olive have shown that rating _and_ ranking changed sighted compared to blind), if there is some grey you must admit that one might be able to learn to deal with his bias (something that Toole/Olive haven´t investigated as far as i know)
In short, hey it is pointless, but i do it anyway as it is difficult to do it otherwise. 🙂
Really not wanting to be offensive, but the argument was not "difficulty of test" but "uncontrollable bias" .
You really should try a blind test on that one; you might be in for a shock (assumed that you were not used to blind testing) 🙂
I´m sorry, but that is not true; dbt is part of scientific methodology and is used if you were searching for reliable results according to scientific standards; everything else is just experimentator bias.
And please remember, a dbt itself doesn´t remove _the_ non-audio bias, it just removes a bias that is introduced due to peeking.
All other bias mechanism have to be addressed too.
Look at wikipedia for example for an impressive list of possible bias mechanism and try to figure out which of these are affected just by "blinding" .
@ terry j,
sorry i forgot to address one point. You did ask, why the sighted listener did not need any sensitivity control or something else.
My answer would be simply, that if someone stated that he hears something, it should be clear that you can´t trust in him; it is just a subjective statement and if you don´t know him and further if you haven´t shared some listening experience you can´t know whether his statement has any meaning or if it is just true.
A DBT usually claims a lot more (at least it is notoriously used so some time later) and therefore - according to scientific standards- it has to be shown that it is an objective, reliable and valid test.
Wishes
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That is a fallacy. "Just Listen" is what one does under controlled (blind) conditions, something you abhor.
What you do (as a "subjectivist"), is "just" see, know and listen. The "see" and "know" part being critical for "hearing" what you hear.
Again, blind conditions is when one would "just listen".
So you admit your senses fool your brain occasionally. But not always. You determine this how?
Well, this is just hilarious. I think you are psychic or something! My next few projects that I have lined up are a good USB DAC to get music from my computer, a set of active speakers in the mold of the Linkwitz Orions (if not the Orions themselves) and the accompanying amplifiers. I was leaning toward powering this with something small like 8 X SymAsyms, or just a bunch of LM3886 based amps.
I already have a pretty good sub (based on the 12" Dayton Reference HF driver) driving the low end of my North Creek CM-7 MTM kit speakers (slightly modified), which are a pretty decent set of mid-grade speakers, even if I had almost nothing to do with designing them. I did tweak the EQ of the sub amp to bring the really low end up a little since it was just a little under-powered in the 40-20 Hz range, and I am sure I will revisit that when I finally get my couch in my basement/office/listening room that will surely effect the sound of my system. I am driving the towers with a set of LM3886 amps, and I generally don't have too many complaints about the sound quality.
That being said, I know it can definitely get better!
I use 16 AWG "zip cord" for my speaker cables, and haven't found any reason to switch to anything else! I dropped 12 AWG Romex in just to see if there was any difference, and couldn't tell a thing. I figure that the speaker cables aren't doing anything on my relatively inefficient speakers anyway, so who cares.
Thanks for the other tips too. I haven't had any time to get into them, but I'll take a look in the future.
Any other opinions from the "cables make a difference" folks as to when the tipping point should be as to when to worry about cables vs. other components?
David
Yep. If your amp is stable (likely if you didn't spend $10k on it), then it's all down to getting the frequency response variations small enough. My speakers have a fairly flat impedance curve, but if you have something pathological (like John's WATTs), 16 gauge just isn't going to cut it, at least if you want to avoid a hole in the midrange. 0.3dB is probably OK for most, perfectionists and worrywarts might want to go as small as 0.1dB.
Of course, if you're using an amp with a high source impedance (e.g., SET zero feedback job), the frequency response variation from the cable gets lost in the noise.
Metaphoric. The source impedance of a lot of those expensive tone controls posing as amps will overwhelm the resistance of the cable.
Before. They agreed that the test setup allowed the differences to be heard. The mind control rays were apparently turned on once they had to pick "x."
edit: That is, they agreed with the ABX box (or the other controls) in place, but knowing which was A and which was B.
edit: That is, they agreed with the ABX box (or the other controls) in place, but knowing which was A and which was B.
Which means, and it meets my memory of the description, they feel confident as long as they could do a A-B comparison but that changed with the X-part of the protocol.
First that mirrors exactly my experience with participants not used to listen with an ABX-box.
And furthermore if the participant is already unsetteled due to the protocol, don´t you think any additional non verbal communication could enlarge the uncertainty?
It doesn´t need any "xray mode" just the normal behaviour of people.
Or otherwise could you cite some literature where the fact that non verbal communication will only work in one direction is investigated and confirmed?
Wishes
They're already selling, people are swearing by the difference it makes. It's not really Enabl because that's for speakers but they say the principle is similar. Personally I remain skeptical.
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