DBT Report

Aaah, the whispering mafia strike again. Tell you what, I'll try to cope psychologically, and if I can't I'll come back begging for forgiveness

 

Pete,

Do you apply the DBT correction factor before you posted ?
Just curious

 

:lol: Hey, sometimes it takes me a couple of attempts to get my posts to their final, perfect state

 

But surely the possibility of Type 2 errors corrupting his findings are enormous?

Chris, you may have left one small thing out. If you can perform the test as you so lucidly described it, then you will end up with some statistics

As we know, there are "lies, damned lies, and statistics". The result is then typically left open to interpretation by the examiner, who of course, will have a subjective bias. So we are back to square one. I'll just have a bake off I think

 

Really? that's great, Rome wasn't built in a day (apprantly).
Seems you may be attemting to apply a rumourious algorythym to your DBT equation, do be careful, you may yet corrupt the results, and a 0.01% offset will produce seriously misleading figures that will contaminate humanity for many an generation
Remember Pete the fate of audio kind is on your Shoulders

 

OK then, we basically agree - I'd certainly agree with bottleneck's post above too. And for the record, I personally have absolutely zero interest in performing any blind tests on anything I'm thinking about buying - but then I readily acknowledge I'm not buying based on sonic grounds alone.

 

That's an interesting one.

The large manufacturers are interested in bringing out flashy-looking products, positioned at the correct price points in the best market niches, launched using the right reviewers and sold by the right dealers.

The debate that we've been having, whether we're pro or anti DBT, objective or subjective, cabling or non-cabling is about quality. For us, perceived quality is the main criteria by which we judge hi-fi.

Call me a cynic but I'm not convinced that quality comes very high in the priorities of the large manufacturers.

 

Bottleneck,
That is very comprehensive list. Lets put it this way. Considering so far we have only claim from 'studies' of 1 test subject. Or man with a few friends where they all know the identity and price of each cables being compered. Or worst with study of 2 people where we have a man and his wife who the latter is usually very deaf or seems to have no interest in hifi what-so-ever but remarkably can hear differences of these audiophile cables from the kitchen.

I think we could lower the standard from a 500+ people DBT study. Lets try to see if Zerogain could manage 10-20 SBT people to start with. It would be a big improvement to what is available so far. If we get 50+ DBT then some one should certainly write it up and submit it for publication.

 

Hi Wolfgang.

My question is this - if DBT is a scientific method of assessing difference, then there MUST be levels/quantities of sampling where we can say we have reached statistical significance. Do you (or anyone) know what that is?

1) How many people in the sample
2) How many times you need to perform each sample with each person.

Im looking for what the scientific community accept as a large enough trial that firm conclusions can be drawn, other things being equal. Im sure these figures are published and listed.

A figure plucked from the air wouldnt meet these guidelines, whatever they are.

If we cant get a large enough group together to gain results that will provide a result of statistical significance, then the exercise would become futile I feel.

 

Take one audiophile, two cables selected by him with typical parameters (99% of which have, this should not be an issue) he swears on his life he can tell them apart (obvious changes in sound), DBT him 20 times. have a break after the 10th time to recharge the senses.

if he gets 20/20 (even 18/20) I would believe that he can hear a genuine difference. i.e the difference is real.

20/20 the odds of that being a fluke are highly unlikely, lets keep this realistic.

20 times IMO is adequate and easily done in domestic circumstances

We are looking for the obvious differences that the said believers typically hear, those differences should be detected 100% of the time if they are real.

I think that trying to disprove subtle differences is a waste of time, that's not what the cable debate is really about. Subtle differences are not what were looking to detect. A subtle difference may only get 68/100 from the claim-e but that result would still be considered as a probable difference/reason to investigate further but would require at least 100 tests (not suitable for domestic testing).

If we can find people who hear obvious differences who can back it up by doing this simple test then this gives rise to believers having more credibility who hear subtle differences. We need proof that similar cables can sound vastly different first.

It can be done if all parties are realistic in what they are trying to achieve, sceptics and believers should work together rationally instead of against each other. this last sentence is always the stumbling block! That is the only way forward IMO

Oracle

 

I bet my wife can hear better from the kitchen than you between the speakers...

 

My wife has pretty good hearing too (she was brought up with an audiophile father). It's her sight which I question.

Gives me an idea though. Wives from the kitchen could make a much easier DBT - no blind-folds needed and precious little prejudices as long as you don't mention the price.

 

Excellent idea Steve

Reminds me of that song that goes.....

Wives in the Kitchen
Wolfy's in the rack
Tony's in the Alley
With a baseball bat.....

 

for the benefit of Merlin,i will try and keep my response non-governmental.................I heard a difference when going from QED SA to Isolda,so i agree i am happier that i got the Isolda,or more content because i spent more money

 

Yes, if I mention the price she will always pick the shipest...

 

Bottleneck,

I remember the thread and your comments very well indeed but there is no need to apologise as I was not offended. The different views, beliefs and preferences of all individuals who inhabit these forums are what make the regular debates so interesting and sometimes so heated. My views on blind testing are not as hard core as some of my fellow supporters of the art. FWIW, I do believe that there are differences between cables whether listened to sighted or blind. However, I must qualify that by saying that IME, differences between some cables are only marginal where others sound indistinguishable. To believe otherwise is folly IMO and perhaps could explain why the cables sharks are springing up all over the place like wild mushrooms due to the gullibility of audiophools. Having said that, I must admit that I use also use well regarded audiophile cables but they cost me zilch (a gift from a fairy godmother) so I am not under pressure to hear a huge difference especially when you consider the crazy prices cables are commanding these days. I also don't believe that all CD players and amplifiers sound the same whether listened to sighted or blind. But here again, hype, reviews etc could influence what we hear in a sighted test. However, when it comes to spending my own money on a piece of equipment, I prefer to take out all external influences that could affect my choices such as the make, model or technology (e.g. upsampling employed) of the component, previews glowing reviews etc. I feel it is important that my choices are made based on what I hear (musically) not what I've read or heard about a component or cable. Also, I buy components that would last me for a few years not a month or two so the right choice is essential and this perhaps could explain why you never see posts from me seeking advice on new components or declaring a new upgrade every month or so.

My initial selection of components first takes place via sighted listening at dealer showrooms vs my own gear. I then take home the components that impressed me the most and that I also feel I could live with and be happy to have in my listening room for years. I agree with you that if a component makes little or no difference, then it should not be pursued further. My own LBTs simply help me separate the wheat from the chaff without external influences such as pre internet discussions, reviews, hype etc. Therefore, although I would listen to components on loan at leisure, I also put my hearing and sighted preferences to the test by surrendering control of all the gear and my listening room to friends who make sure I cannot see the component or cables being demonstrated. This I must admit throws up interesting surprises and could even explain why components I purchase using the LBT method stay in my system for years rather than months. I am what can be considered not just a music lover but also a long-term investor. As to the last digital (CD player/DAC) fest that I held at my house, well I still haven't purchased a new CD player yet. I am still looking for that CD player which can be as musical or even sound better for sensible money than my tweaked Michell Gyro SE turntable, Trichord power supply; upgraded SME IV arm, Grado Reference cartridge and Graham Slee Era Gold V phono stage. In the meantime, I'll just keep on buying LPs as every true music lover should do.




Enjoy the music,

Lawrie.

 

Ah Merlin,

It's just as well that I was only drinking water (and not coffee) when I read your post as I spat out the water in my mouth all over my keyboard as I was laughing so much at your post above. The last time I read such comments was on the school playground - oh, happy days. You may have your head stuck right up inside your *rse and you may be an arrogant and pompous tw*t but your one redeeming feature is that you are hilarious. I've never laughed so much reading your comments dude - no joke.

What is a joke however is your mention of the word 'constructive' in your post. If there is anyone on this forum who should be contructive it should be you. You ridicule everything and everyone whose views and preferences don't sit well with your inflated ego and even go on to pick fights with distributors like Audiofreaks who don't see things your way and then rush to forums like these to cry wolf at being allegedly threatened whilst neglecting to give the full story of what actually happened between you two. This has been your stock-in-trade on these forums and maybe it's time to take your own advice for a change and try being constructive.

When I posted about the CD/DAC player tests that I held at my home under sighted and LBT conditions, you were not being constructive in your comments were you? Instead, you commented that I was being a bore to everyone by publishing details of my CDP tests (which were no different to others on the forum) the only difference being that my final tests were done 'blind'. IIRC, you even went further to say that as a result of my post, I had become the subject of private jokes amongst forum members, another comment which had me splitting my rib-cages with laughter. So you want to talk about being constructive? Get a life dude.

Hey Robbo,

Was that post meant for me or for Merlin. Anyway, just don't sweat it out Robbo, it's only hifi and an internet forum at the end of the day but you are right though, I am one of the most decent, well balanced and friendly individuals you'll ever hope to meet - honest. My radar just pointed to the lack of comment from you on this topic that's all.

As for my posting style, well I'm sure you'll get used to it someday, WM has.




Enjoy the music,

Lawrie.

 

merlin, lawrie - there's no need for personal insults like some of the above. No matter how heated the debate here we should be able to get by without calling each other names

Michael.

 

Writing very long posts ensures that I, for one, don't read 'em.

 

Michael,

Points duly noted. However, if personal insults are an issue with the Moderators, I feel that a warning should have been issued to Merlin on 15th April, when his post first hit the board. However, none was given until now.




Enjoy the music,

Lawrie.