DBT Report

I can't be arsed to write this post again 3 times it's failed so he's an abridged version
Blue leds no joke they work superb, sorry If you didn't get, I though a little humour may help a bit, but obviously not
I have no freqency responce below 28hz
Ian, No sidey's at you, why did you think so?, Turner is a general reference, I'd written a long reply about Int's and how arragantly asswholish they are but the bloody computer dumped it
Quite a pice of work for moi too, even more annoying
As for hearing not hearing things, so people do and others don't, deal with it, its very easy to do.
I'm seriously hacked off that post was lost

 

Who the f..ck do you think you are to tell me what to do... :bub:

 

whoa there Billy

fall out the wrong side thismorning

 

(that,s the whole thread not Antonios comment)

It,s not Friday already , is it?

 

Isn't it rather closer to 50% than 25%? And in any case, no, I don't think this has any relevance to the cable argument - as measurements have shown, sensitivity to 3dB level changes won't help you identify different cables.

 

I wonder how you would have answered a stupid comment like that about yourself...

 

I think this is the best possible way to settle this argument. My hearing is not good but I'd be up for swapping cables, keeping scores and I am impartial because I have no axe to grind with either camp. Just in case you need a volunteer.

 

Is there nothing to be said for a hifi version of Top Trumps?

I'm sure we can resolve these apparent disagreements like gentlemen.

 

With a rather large gun

 

I'd rather use mine...

 

It's an interesting idea. The goal would be to determine whether our listeners can tell the difference between cables. One way would be to see if they could identify the cables as Cable A and Cable B.

Of course it's possible that the cables selected are so similar that there's little or no discernable difference. Therefore the experiment must use cables that are reputed to have different sonic characteristics.

Then, what cables are we changing? One or more? IC, speaker or mains?

Personally, I'd rather the listeners were musicians rather than audiophiles. None of those 'Deaf as a post because I used the pa speakers as headphones' rock musicians either.

I have more issues but my general point is that the trial should be designed in a way that most, if not all of us are happy with it. Otherwise its conclusions won't be accepted.

We'll need a Trial Discussion Thread. Could we do it without squabbling? :sigh:

Absolutely, Mike. There's no question.

 

I totally agree. Unfortunately, I'll still be in Portugal that weekend

Mike, if you're serious about setting up a proper DBT then we probably do need a thread to discuss the details, what will be tested, what ancillary kit will be used (CDP, amp, speakers) and the test routine.

It's going to be pretty dificult to have a test that is truly double-blind (ie where neither the listeners nor the testers know what's currently playing). In the case of ICs, you'd need a remote controlled preamp and a computer with an IR output to make the the A/B selections randomly. With sources, mains cables and speaker cables it's considerably more difficult to do properly.

If it's going to be a few lads down at Mike's place with Dev ducking behind a velvet curtain from time to time to swap things over it might be fun (or not ) but it won't have any real value.

Michael.

 

It is behind my comprehension the importance of the person who does the changes not knowing what he is changing...

 

Guys, can I suggest that we keep it simple. I.e. use the minimum number of boxes, cables etc. Ideally stick to the same source, amp, speakers and if we can, use no more than 2 sets of I/Cs, mains and speaker cables. After all, we only want to prove that there are differences between cables, not that a is better than b but not c etc.

If we pick 2 sets of cables and switch between them, say 10 times and the listeners can consistently identify cable a from b then later on perhaps, if time allows, look into "the laws of demishing returns" by comparing more cables (cheap and expensive) to see up to which point they make a difference, if that tickles your fancy.

How does that sound? (forgive the pun ).

 

Don't think it matters either way to be honest.

 

Just makes it almost impossible to do the test, IMHO...

 

You see Guys The rubbishing has started already. it's not under laboratory conditions with a fricking one legged Martian performing the changes whilst indulging in digital intercourse of a inter planetary nature.

Why bother We'll get three people listening whilst changes are made behind a curtain and the results duly noted. That has no real value? Plllleasee

Thank god the kit i buy isn't designed by robots like you.

 

Chaps,

Do I detect disquiet in the ranks or are the "much hacked to death" blue LEDs not burning brightly enough? Wasn't it a few weeks ago that none other than the Golden Eared Merlin and his gang laughed me out of town for suggesting that I use LBTs (Lawrie's Blind Tests) conducted by friends as a way of home auditioning cables and other pieces of equipment after they have been selected at dealer showrooms? I also stated that my methods were not laboratory perfect but it took away all control of the process away from my hands and eyes leaving only my ears to do what they do best and that is, listen. Now what do I read - a suggestion to do an LBT known in these parts as DBT? Spring must indeed be in the air.

Sadly though, as good as the suggestion is, I suspect it would just be another version of the farcical Myth Busting Day where unsurprisingly, no myths were busted or at worst, just the usual bake-off. I hope I am wrong though. Anyway, in case the tests do go ahead, I have in my possession the latest audiophile balaclavas in leather and latex which I could DHL to you in case you run short. I must warn you though that the different smells given off by these two materials could have an effect on what people hear - it all depends on whether they are partial to leather or latex. What an interesting forum!




Enjoy the music,

Lawrie.

 

I'd be very happy to take part in a DBT, but I think it'd have to be presided over by a neutral party, which may be difficult to achieve.

WM - I didn't understand a word of your post, dude, otherwise I'd respond...

Antonio - relax. You seem to be getting very exercised by all this.

-- Ian

 

It's a very well established condition that in order to do a valid scientific test of this sort (whether in audio or medical research or anything else) that nobody must know which is A and which is B at the time of the test, that's why it's called a double blind test. There's more than enough literature on the subject on the web but the basic reason is that no matter how impartial the tester is they can (conciously or unconciously) influence the test results.

It doesn't make it impossible to test but it doesn't make it easy but it's the only way to do it and get valid results that no one can quibble with.

merlin, I'm not rubbishing anything - I'm just saying that there's no point doing it if it's not going to be done properly. You can try and ridicule long established principles of experimentation all you like but it won't make a "bake-off" style blind test any more valid.

That's not really an impartial attitude to start off with is it? That's exactly why testing has to be double-blind so that the tester can't influence the results, whether deliberately or not.

We shouldn't be setting out to prove anything, instead we should be setting out to see if differences between cables can be reliably distinguished in DBT conditions.

Michael.