Anyone heard the GBP7000 NAIM CD Player?

To add to what I said above, I'm pretty sure that just if a DBT with 16 tests were setup and people had to say whether "A" or "B" was being used but in fact nothing was ever changed that the results would be no different than what would have occured by chance (ie statistically insignificant). This control experiment would show that we're just as incapable of determining "no difference" as we are differences (so the objectivists keep claiming) in a DBT.

This to me would somewhat invalide the method for hifi testing. If the method were reliable then I would expect every person to get 16 our of 16 in a "no difference" test (ie, choose "A" for every test or choose "B" for every test).

In other words, compared to a science experiment in a lab, the "measuring equipment" (our ears and associated brain psychology etc) is simply too unreliable for DBT hifi tests to be valid.

Michael.

 

Ah but don't forget, you'd need repeat this test on not only a number of different testers but also on the same tester a number of times to get a statistically as accurate set of results as possible!

 

Ok, replace "run over" with "branch falling on head" or indeed heart attack or cancer or ...

Cheers

Jason

 

This doesn't answer the question of why we can hear a difference in our systems under non-double blind conditions but refuse, in some cases, to believe that a double blind test can be setup that accurately tests our ability to detect a difference.

Surely it is not against the wit of man to for example create a test over several weeks that is still double blind?


Michael said: In other words, compared to a science experiment in a lab, the "measuring equipment" (our ears and associated brain psychology etc) is simply too unreliable for DBT hifi tests to be valid.

There seems to be a lot of double standards here. People will claim that they can compare cables/amps/CDplayers for example all day and that the differences are clear and obvious but then refuse to believe that the test is valid if they can't see which cable/amp/CDplayer is in the system. Or am I missing something? Or are we really so fallible? btw I think the people claiming to detect differences when there are none is simply due to noise in the system. As you try to detect a difference that is smaller and smaller noise will give you more and more error. In the case of trying to detect a zero its all noise so the results tell you that you have noise in the system whoop-de-do, doesn't invalidate anything. If the people claimed huge differences that is a problem.

As I said before I have participated in several display double blind (bizarre idea, blind test of displays ;->) tests and they have given some rewarding and sometimes surprising results.


Cheers

Jason

 

Sorry Michael - just plain wrong on this one.

In terms of the sound kit makes our ears are the only measurement equipment that is relevant. DBT is the principal method of eliminating external influences. If we can't distinguish between two bits of kit on the basis of hearing alone, then any jaw-drops etc are clearly just psychology and not directly related to the sound.

The point of repeated tests (DBT or whatever) is to determine the presence or absence of consistent differences in the presence of noise (aka intersample variability) by reducing/averaging the effect of the noise. A scatter of results in the no-difference test is indeed saying that our measuring equipment (ears etc) is unreliable, hence the necessity of multiple tests to reduce the effect of noise on our measurements.

The fact that our perceptions change over time and in response to repeated stimuli is a complicating factor on the simplistic analysis that I'm sure some statisticians have worked out how to accommodate.

The fact remains that an equivalent DBT is clearly more valid than anything sighted. How large a difference is required for a sighted test to become equally valid is probably the issue here, vs the extra hassle of doing it DB. I really can't see what the anti-DBT camp is arguing about: conceed that DBT is better, but that sighted was good enough given the amount of dosh we were prepared to throw at things, and the risk we were willing to take that we were deluded. If making the right choice were a matter of life and death I'd do an extensive DBT and buy the cheapest of the best bunch.

Absolutely. They are an attempt to remove bias and extraneous influence from a subjective test.

 

the double blind testing total immersion gimp suit.

 

Life's Doers and Life's Procrastinaters

So would he have been better off being someone who walks around with a back-pack full of back issues of New Scientist and a laptop PC running a risk analysis spreadsheet which gets refers to every time that person needed to cross the road and thus avoid such things? Oh, and the ever present agonising wait to see if a decade old theorem devised by his favourite AI professor at MIT could once and for all decide for him whether he liked that piece of music that he heard 5 years ago or not.

Guess we all like to pass the time of day in different ways. So long as we're all enjoying ourselves, I have no issues with that.

 

Well, depending on the seriousness of the blow, i would either be dead or merely injured.

In the later instance i would have to rely on the internal medicinal techniques that nature has provided me with, leading to either a full recovery, or at worst, a diminished capability.

In the former, i have absolutely no idea. Perhaps with the possibilities of cryogenically frozen bodies, i would have the opportunity to be blessed with life's opportunities once more. Certainly, bereft of such advances, i would struggle to be elected to the governing body of falling branch evasion techniques.

Whatever the fate of the falling branch, i would not feel so acutely the headache of deciphering immortality, the burden of responsibility in relation to the infinite and unfathomable complexities of quantum physics, the appetite for life prolonging and tasteless foodstuffs, the necessity of constucting utopian and unimplementable theories for existence nor sociopolitical and abstract quasi destructive systems and categorisations of all possible known matter, biotic or otherwise , and an infinite list of other fabricated modes of pissing in the wind with a large marrow stuffed up ones arse. Of course i would be bereft of the pseudo pleasures and fireworks that the very same bistro serves to its enlightened diners to sweeten the bitter taste of such a large, unpaletable and undigestable meal served on fragile bone china.

My headache would merely be a physical one, which even bereft of Anadin Extra, i would feel adequately able to cope with, and look forward to the ensuing pleasure riding on the crest of a wave on the ocean of pain.

I have no desire to hold on to the flotilla of floating turds riding precariously across the sea of pain, legs dangling among natures sharks, whilst the head bobs along with the shits of reason, gasping the air of complex molecules which mutilate my organic thinking cells.

I have no counter theory. Pissing on the existing ones employs enough of my time, until it occurs that the branch falls on my head, and i will be relieved of such pastimes.

 

I hope the tree survived

 

People tend to get what they ask for.

Cheers

Jason

PS. I can't agree with the above. Yes a lot of so-called progress isn't but I'm quite glad that my and my families life expectancy is double what it was a few years back. Also as my daughter was born 10 weeks early I am pretty pleased that medcial progress has allowed her to survive and she will now go on to a hopefully normal life. If you are so pissed off with the current state of play what are you doing participating in it, tapping away at the time wasting, raw material using, polluting box in front of you?

 

Ho humm, Double blind listening tests.... well if that's how you guys want to spend your time

I've tried to run two blind listening tests, and one of two things has occurred.

First time, labelled components (cdps at the time) A to G, then cycled them repeatedly, I did the test (years ago when the Denon DCD-325 first came out), 5 people present. At the start the Denon came top of everybodys list of, this was the best player. Two hours later, 4 our 5 had gone for something less forward and exciting, stating that "B" (the Denon) was giving them a headache. The player that they settled on was the group control, my own slightly aged NAD5440, a good 5 years older than the others.

There were two obvious flaws with this, apart from the very obvious listener fatigue that had set in, it had only taken 1 person to say why they liked the Denon at the start, and everybody had agreed with them, and suddenly they all liked it. Opinion only moved as a group, and therefore, the participants must not communicate else the results are going to be tat.


The next time though, was far more interesting and supports what Robbo's been saying all the way through this thread, and which I entirely agree with:

Three amps belonging to 3 different people, A Nad, a Micromega and an Audiolab, blind listening tests, and the other two people couldn't tell the diffence between them. I could, but again I was running the test so I wasn't blind and don't count. Perhaps a bit more treble here etc. was coming back, but put any one on and they couldn't say which of A, B and C it was.

Most disappointed I was, but as they decided they couldn't tell the difference (the bloke with the Micromega was gutted btw) I suggested they swap their amps for a week (I was happy with my Audiolab and kept it ). The Nad lasted two days with the Micromega owner before he was banging at the door wanting his amp back, and the Nad owner with the Micromega? I thought he was going to try and elope with it!!

But remember, in the blind listening tests, they couldn't tell them apart.

Cheers

 

Doesn't this just mean that the detailed methodology of the tests is not good enough? If you had boxed the amps in identical boxes and let each person compare them over several days in their own systems it would still be double blind!

Cheers

Jason

 

I used to kind of advocate blind testing, but then I tried it and realised that it caused me a headache and for some reason, I felt like I heard things differently to normal. I feel there is a reason why people fail on blind tests, but I dont quite know why, if the difference is there. I'd say it was a useful tool, but I'd say it was flawed too. Timpy's example is a good one...

 

Cookie, stop humouring these inconsquenical creatures, merely teasing them, is but a waste of an long-ago theory, as you well know.
The fact the branch would never fall on your current form, is a concept these 'mortals' will never able to comprehend, yet alone begin to fathom
If by some inexplicable Phenomenon, such as a black hole passing at near right angles to solar systems pivital axis, then you would just revert to your 'normal state', quiet puzzling these humans, when such passion is show for pieces of crudely formed apartus that generate a form of sonic distrubance in the surrounding local atmosphere, when they own impending distruction, is all but immanent, such triviality bemuses one ?, oh what an interesting species, shame oh relative spell on this 'Freak show' is so restrictive to our studies.
A fitting epitaph The Earth, showed promise, even understanding, but snuffed out, cruely by it's obsession with irrelevent misgivings and double blind testing, to realise that the universe waits for no man' shame really, some of the inhabitants show great forward thinking.

 

Blind tests are not inherently flawed. Sighted tests are not inherently flawed. The sound of a component in both will remain a constant. It is the listener that is flawed.

 

I'd love to know if they have. IMO it's one of the main reasons why DBT testing for hifi isn't particularly meaningful.

OK, I will conceed that, in theory, a DBT is better than a sighted test of the same duration. I do however think that proper, reliable evaluation of hifi can only be done over much longer periods of time, listening to a wide range of music where a DBT type arrangement is simply not possible. Just as I wouldn't trust the results of a DBT that involved 16 tests of 1 minute each neither would I trust a 16 minute sighted A/B comparison unless the differences were so huge and obvious that there was absolutely no element of doubt (which doesn't happen often when comparing kit of a similar level).

As an example, when I recently compared using an Apogee Wyde-Eye digital coax cable against a (cheaper and supposedly inferior) Ixos optical cable between my transport and DAC the difference was as clear as day - there was no element of doubt. The optical cable was clearly superior. Note that in this case the result went against the psychology - the winner was the cheaper product that I already had a prejudice against.

OTOH, I recently had a friend's NAD S300 amplifier in my system on test and I couldn't swear that I would have been able to tell it apart from my Arcam FMJ A22 and I certainly couldn't pin down or describe what the differences were.

Also, when I've compared analogue interconnect cables the differences I've heard have all been in the "I might be imagining it" category. In general, I'll only change something if I can hear something that I'm definitely not imagining and if that's the case it doesn't need a DBT test to show it.

Michael.

 

Hi Jason

Boxed the amps in identical boxes..... I think you over estimate the amount of trouble I was prepared to go to! Anyway, who's to say that re-boxing the amp wouldn't change it's fundamental character?

Of course you can say, that the system the blind listening test was performed trough wasn't transparent enough, the cables weren't good enough etc. etc. or it suited one amp more than another, or in this case probably, suited none of them. But you aren't ever going to get any from this though are you? How are you going to factor in system synergy into your blind listening tests for instance?

Cheers

 

You're right it is bullshit. I find it unavoidable. There are many conceivable sides to every argument. Unfortunately for me, i have never been that able at making a leap in one fixed direction as a consequence. If you are able to do so, then hopefully that is to your benefit, and i mean that sincerely. But that is also why you are able to raise your voice. I make no judgement, which should be able to be deduced from the state of affairs.

Does it aggravate you that i am 'participating in it'? It shouldn't as i'm not doing anything other than spouting bullshit. If it's a genuine enquiry, then it is only a further one which i cannot answer adequately. I know no more about my origins than i do about my destiny. I've no desire to kill myself if that's what you mean? Probably a topic for after lunch though.

Maybe if you lived a 'few years back' you wouldn't need twice as long to do everything that is 'necessary' now? What's the optimum life span? What's the difference between infinity (whatever that is) and nothingness (whatever that is)? What's the difference between 40yrs and 80yrs? Maybe 'the solution to the problem is to be seen in the disappearence of the problem'. Well, that's quite a nice thought, but also difficult. Once you've seen it, there is no going back.THIS IS THE ONE MAIN SERIOUS SENTENCE I WRITE HERE : i'm NOT taking the piss out of anyone, if anything it will likely be extracted from me. Most of what i am burbling on is quite serious in intent, and it passes the day quite nicely. I could swap my job for a more demanding or 'scientific one', but it's by far too much aggro (a bit like a blind test - hey, if they work that's great - but i couldn't be arsed. I picked my most recent speakers because they were cherry coloured - so i am below contempt from both sides of the camp)

I have no problem with blind tests or otherwise, whatever picture i have ambiguously painted. In fact i really am so far from giving a shit, i'm practically drowning. I'm just passing the day with fellow life travellers, hopefully not aggravating anyone too much.

.....I'm going to ask for a large bowl of cookies in that case.....

Best of health to your daughter , i have a nephew who went through the same experience. He is now busting my balls all the time, dribbling my best cookies everywhere whenever he comes visit. I always make sure i get extra in though now

 

Relax, I'm on your side If you can't tell, it's either because I'm trying to take a relatively balanced view, or because I'm not clear enough - and it's difficult to tell the difference between those two possibilities...

Re Leventhal, I think you're trying to pick an unnecessary semantic fight with me here. To be entirely precise, yes, his argument began from the premise that the probability of detection is small, but it's surely not unreasonable to define a "small difference in quality" as a difference for which the probability of detection is small. Leventhal makes essentially the same assumption in his own preface to the Stereophile discussion:

I do know that many listening tests using the ABX comparator... are conducted and analyzed in such a way that subtle differences [my emphasis] actually heard by the listener will likely go unidentified by the experimenter when the data is analyzed.

For those who haven't read the discussion, Leventhal's point is most emphatically not that DBT is invalid, simply that many of the extant statistical analyses of the results were flawed. He wanted more DBT results in order to be able to draw any kind of definitive conclusions - not to junk the whole idea of DBT as the Stereophile editorial people seemed to think... And on the subject of Stereophile's "interpretation" of Leventhal's work, I'm inclined to think that their abuse of his results arises from the writer's incapacity to understand them rather than - as you suggest - a cynical manipulation for their own purposes. Either way though it's pretty irresponsible for them to publish nonsense like that on a subject which is obviously close to many people's hearts.

Perhaps for the sake of easier discussion we could call a difference which is very readily detectable a "large quality difference", and a difference which is detectable only with difficulty a "small quality difference". That would still leave most of the subject matter under debate under the category "no quality difference " And if you read my post again you'll see that I made a similar comment regarding the claimed huge differences found under subjective testing conditions.

But I see the subjectivists have resorted to avoiding the debate through trying to ridicule it, so maybe it's heading towards time to wind the thread up

 

Yes. But it is valid I think to ask questions about how the testing is conducted. Listening to the same thing 16 times is pretty indigestible, and I doubt even the best statisticians have a reliable method of calulating aural indigestion (or even the effect of needing to go to the loo) over time...
My questions with DBX w/r to hifi is one of methodology. I don't doubt that it is possible to design a reliable test, but a simplistic listening "blitz" is not a very convincing approach and one I would suspect that *tends* to lead one conclusion.
IME (as a guinea pig), DB taste tests are *never* done (this is IME ) 16 times. You will be given three or four tastes at a time to evaluate. In addition, some people are better at evaluating cetain tastes than others.
SupposeI was a manufactirer of expensive cables (as an example). What *possible* reason could I have, asuming I really believed in my product for *not* being in favour of testing. If *jaw drop* is not just jaw-jaw, then the superiority of my product would surely be established.
Just a thought.