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post #361 of 390 Old 03-13-2006, 01:19 PM
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Originally Posted by Randybes
I have an Escient system as well (both the DVDM100 for DVD's and DVD e2-100) with 777ES changers on the DVDM100 and whatever the Sony 400 changers (can't remember). I also have a Cal2500 DVD that is supposed to be the cats meow (according to the subjective mag rags) as an analog only or a transport. I have played the same CD over all three players and after adjusting levels, I can't hear any difference (pre is a Lexicon MC8) speakers are Salk HT3a.

Can't say that means anything for anyone else, and I am skeptical so I could be biased the other way (was not blind).
Very interesting results. Part of me wants to try a very high-end transport in my system (my neighbor has a 17k Krell CDP) and part of me wants to be happy with what I have. I'm sure I wouldn't give up the Escient for anything other than an enormous improvement, and I'd rather not know what I'm missing! How's that for willful blindness! :)
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post #362 of 390 Old 03-13-2006, 01:21 PM
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Originally Posted by Chu Gai
Well, here we're dealing with a couple of things, equipment wise.

One is that your changer probably didn't upsample and may've had issues with the reconstruction filter. Not an ususual thing for older equipment.

Secondly, as was mentioned in my earlier post, once you start breaking apart things that were originally designed to work together, $hit starts to happen.

As has been mentioned in more than one thread, an SPL meter is inadequate. You need to ensure that levels are matched and that there are no imbalances. A multimeter is much more accurate and much quicker. Give some thought along those lines.
The changer and the transports were both being upsampled by the external P-1A.

I know that an SPL meter isn't adequete to level match, but I'm not going to repeat the test. I've decided to stick with the changers + Escient system. In a few years when I upgrade again (speakers and amp next time), I will do some serious critical listening of various transports to see if I have changed my mind.
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post #363 of 390 Old 03-13-2006, 01:27 PM
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Chicken!

"I've found that when you want to know the truth about someone that someone is probably the last person you should ask." - Gregory House
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post #364 of 390 Old 03-13-2006, 01:49 PM
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Chu, you crack me up:)
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post #365 of 390 Old 06-12-2006, 01:59 PM
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Why are blind listening tests not so good.

Usually they are conducted in one system (amp/speakers) components have interactions with each other which means in audio some systems work better than the sum of it's parts.

It is possible to get a well auditioned and carefully selected group of hi-fi components that cost £800 and sound a lot better than £2000 system selected without auditioning.

So the DBT may end up with a system that suits one player better than the other.

A good hi-fi reviewer (and I mean reviews that come from magazines who's parent company doesn't have intrests in some manufacturers) Will audition a product over a number of weeks or even months and use them in a number of diffrent systems against a reference product they have use for years so know it's sound inside out. They will also use recordings they know inside out and have heared on 100's of diffrent systems....

Often a DBT is used on 1 system (sometimes 2) and is a panel of people and has a selection of diffrent recording types... In this case most reviewers won't know the system or recording that well so will struggle to immediatly put their finger on what has changed in the sound let alone be able to describe the changes.

I own a Pink Triangle Da-Capo DAC with Cardinal Transport (connected to DAC with clock lock), I also have a Battery DC PSU for the DAC. All bought 2nd hand (so spending a lot of money doesn't influence me wanting to hear a chane).

Now diffrences in CD are very small because the DAC used is a simalar CMOS chip in most cases and diffrences come down to Power supply quality, compnent quality, circuit design and the output devices. In good quality players the diffrence is small. If you compare a multibit DAC to a Single bit you will hear a much bigger diffrence in the way each player portrays the audio...

The last big thing that creates diffrences in CD players is the Digital Filter and the way the are implimented.

Now becuse the diffrences are smaller in most CD players you either need a stupidly transparent system that will show every flaw in the system (studio's need systems like this so they can hear every minute change in the recorded sound). If you don't have a system like that you likely won't hear a diffrence.

ATC speakers are very good at revealing every flaw in a recording and can reveal from some 60's and 70's recordings obvious tape hiss etc. that isn't apparent on lesser systems...

By the way the PT Cardinal, Da-Capo (with HDCD filter) & DC is one of the best CD players ever produced bar none (regardless of cost).... I doubt anyone would fail to hear the diffrence between this and a £300 player or this and a £3000 player.

I often find people who maintain there is no diffrence (not all but most) and are unwilling to consider they may be wrong, don't have a good seperates system & are happy often with lower bit rate MP3, all in one systems form a large electrical systems or audio from a computer and most havn't stepped inside a real hi-fi shop with a CD they love and asked for a demo. The people who maintain there is a diffrence have invariably owner all in one systems, heared cheaper audio and have owned and auditioned a large number of diffrent systems and combinations of components.

I once went to a 2nd hand local hi-fi shop to buy a 2nd system for a study... I lstened to a large number of compnents and the amplifier I expected to sound the worst actually turned out to be the best, again the CD player I picked wasn't the one I expected to sound best.... I would never have expecte a Sony 3ES amplifier to sound better than a Marantz PM-66 Ki sig. But the sony wasn't just a little better, it was night and day (tried with 2 sets of speakers and 3 diffrent CD players, although diffrent each time the Sony amp was always better)... If I wanted to hear the marantz was better or be led by my expectations I would have had the Marantz...

Why is it so har to belive Cd players sound diffrent when one DVD player is so obviously better than the next - and after all the are just bits 10001100101 :)

Anyway just some food for though and a few thoughts of mine on the subject.

At the end of the day it doesn't really mater that much as long as you enjoy the music and you are happy.
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post #366 of 390 Old 06-12-2006, 02:32 PM
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When I listen long term I match the level to my mood, the music and the gear. That eliminates another artificiality that comes with your type of test.
What's "artificial" about changing ONLY the device being listened to, without knowing what it is? The music, the gear, and your "mood" (it can hardly change over a matter of minutes) are all the same. Long term listening, with different "mood, music, and gear" as you say, introduces so many different variables as to make a comparison worthless.

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Usually they are conducted in one system (amp/speakers) components have interactions with each other which means in audio some systems work better than the sum of it's parts.
Problem is, subjectivists have been told "ok, YOU pick the ultra "synergistic" system that can reveal the tiniest differences, and we'll go with that AND whatever music you want", and they STILL shy away. :)

Why would ANYONE get excited over a difference so VANISHINGLY small that it takes WEEKS or even MONTHS to manifest itself, AND is highly dependent on the particular "mood, music, and gear"?
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post #367 of 390 Old 06-12-2006, 07:29 PM
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You've obviously lost your sense of palpability Robert :(

"I've found that when you want to know the truth about someone that someone is probably the last person you should ask." - Gregory House
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post #368 of 390 Old 06-12-2006, 10:08 PM
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[quote=RobertR]
Problem is, subjectivists have been told "ok, YOU pick the ultra "synergistic" system that can reveal the tiniest differences, and we'll go with that AND whatever music you want", and they STILL shy away. :)


Not only that but when they are cornered, they still fail to hear differences :D

http://groups.google.com/group/rec.a...d91bcb6a1522a0


Why would ANYONE get excited over a difference so VANISHINGLY small that it takes WEEKS or even MONTHS to manifest itself, AND is highly dependent on the particular "mood, music, and gear"?

I just don't see how they could even do that? After all, I doubt they listen that long in one sitting :D If they don't, every new sit down is a new event, not one, long continuous testing for that elusive difference.

But, poor Shanefield tried and failed on a several month long test :eek:

Shanefield, Daniel, " The Great Ego Crunchers: Equalized, Double Blind Testing,: Hi-Fidelity, Mar 80, pg 57-61.
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post #369 of 390 Old 06-13-2006, 04:27 AM
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[quote=CharlesJ]
Quote:
Originally Posted by RobertR
Problem is, subjectivists have been told "ok, YOU pick the ultra "synergistic" system that can reveal the tiniest differences, and we'll go with that AND whatever music you want", and they STILL shy away. :)
Quote:
Originally Posted by RobertR

Not only that but when they are cornered, they still fail to hear differences :D




Why would ANYONE get excited over a difference so VANISHINGLY small that it takes WEEKS or even MONTHS to manifest itself, AND is highly dependent on the particular "mood, music, and gear"?

I just don't see how they could even do that? After all, I doubt they listen that long in one sitting :D If they don't, every new sit down is a new event, not one, long continuous testing for that elusive difference.

But, poor Shanefield tried and failed on a several month long test :eek:

Shanefield, Daniel, " The Great Ego Crunchers: Equalized, Double Blind Testing,: Hi-Fidelity, Mar 80, pg 57-61.
Well I just typed out and posted a big reply but it hasn't appeared on the thread for some reason.

Anyway I have a theory about listening and DBT....

I can hear bats in a local park to me (CD's get nastier the higher the sound goes in the audio range). Maybe why I can hear a diffrence.

So my theory goes.... It's DBT's that are flawed (just a theory), I know for a fact I am not influenced by brand name, price etc. and always go to a listening test and try out 3 or 4 products at length and can immediatly hear the diffrences.

Now if so many people can't tell the diffrence in DBT's I knwo somthing strange is going on.

When I get really into good music and immerse myself (esspecially with relaxing stuff) I would shut my eyes as I found the sound to improve... I, and others, have surmised it is because you are not being distracted by vision and also it helps because you can't see the speakers and so your eyes aren't telling your brain where the sound is coming from.

Well what if that is wrong? Has anyone considered that the brain may be better at rejecting what it is hearing that it considers not to be what it wants to hear. (in the same way a blind persons hearing and smell are hightened, Or how you can hear someone say your name accross a noisey room - ever changed ear in a conference call and noticed it has taken a min or two for your brain to adjust and reject what it is hearing in the other ear???)..... So what if the brain can more easily manufacture a soundstage and seperate out each individual instuments sound when your eyes are closed??? Well it may explain when we come down to small changes in audio quality why a DBT test might be flawed...

I suggest a DCT (remember where you heared it 1st). A Double concealed test... Instead of blindfolding the listner (blindfolding seems to be the common way of conducting this test probs cos it is the only way to do it with speakers) lets conceal the equipment (put both CD players or amps etc. under big cardboard boxes) and conduct the same test but with the listners eyes open...

It would be intresting to see how the results compare from DCT and DBT. I would suggest if my theory is good we will see a marked improvement in results which may lend some weight to my theory.... I will try it when I am next able (next time I am at the 2nd hand hi-fi shop). Maybe a few others could try this and compare results.

After all is the brain not a very strange little-understood beast that does very strange things (how many of us have had their eyes play tricks on them). So it's no great leap of faith to consider with no visual reference to help the brain is more able to manufacture it's own perception of the sound (and make everything closer to what you think it should be)....

Anyway it's worth considering and may explain why the two sides of the discussion could be correct in what they say and belive but may have to alter conclusions drawn from the evidence.... We could have a situation were there are diffrences in the sound between the two items and due to the brain with our vision removed we can't tell between them in a DBT....

Cheers

John :)
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post #370 of 390 Old 06-13-2006, 07:15 AM
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Instead of blindfolding the listner
What "blindfolding"? The term "double blind test" does NOT mean your vision is interfered with in ANY way. "Blind" simply means you have no knowledge of what is being listened to at any given time. It has NOTHING to do with the literal absence or presence of blindfolds. That makes pretty much your entire post irrelevant. :)
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post #371 of 390 Old 06-13-2006, 09:17 AM
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Now if so many people can't tell the diffrence in DBT's I knwo somthing strange is going on.
One of the primary reasons has to do that DBT's are level matched using an VOm. There are others which have been noted but the particular care that's taken in this regard should tell you that this strange thing that is going on is not quite so strange.

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When I get really into good music and immerse myself (esspecially with relaxing stuff) I would shut my eyes as I found the sound to improve... I, and others, have surmised it is because you are not being distracted by vision and also it helps because you can't see the speakers and so your eyes aren't telling your brain where the sound is coming from.
Yes, it's called listener adaptation.

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Well what if that is wrong? Has anyone considered that the brain may be better at rejecting what it is hearing that it considers not to be what it wants to hear.
As I've stated before, and it's well documented scientifically, hearing is a lossy process. The brain selectively rejects information when processing what the ears have detected for long term storage. If you focus differently because of outside factors over which you have not control, you'll process a different subset of information.

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So what if the brain can more easily manufacture a soundstage and seperate out each individual instuments sound when your eyes are closed??? Well it may explain when we come down to small changes in audio quality why a DBT test might be flawed...
You've hit upon the reasons reasons earlier but your interpretation of it is leading you to an erroneous conclusion.

Now you may think and be somewhat correct that you can control your concious biases but there are unconcious biases over which you can't. Earlier in this thread I gave a link to an ongoing research study over at Harvard that you can participate online which will test your biases in a number of areas. Often, you don't even know them hence the reason for the DBT or similar tests. The rest of what you've said regarding concealment, RobertR has answered.

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post #372 of 390 Old 06-13-2006, 10:00 AM
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Originally Posted by RobertR
What "blindfolding"? The term "double blind test" does NOT mean your vision is interfered with in ANY way. "Blind" simply means you have no knowledge of what is being listened to at any given time. It has NOTHING to do with the literal absence or presence of blindfolds. That makes pretty much your entire post irrelevant. :)
Sorry but in a lot of blind tests in magazines I have read about the listeners were blindfolded.... You may know what you mean but it doesn't mean every blind test is conducted the same way.

Also no I can't control what my brain accepts and rejects but I was merely stating with no vision it may by default change the way my brain interprets the information.

I am only trying to premote discussion on the subject (I know what I can hear) and what I hear means there must be more to this than either side of the discussion have said so far.

Sorry if I missed earlier mention of that kind of data (a lot of pages to read through and I must have missed it)....

Again if you compare two good players with the same DAC chip it may be difficult to discern the diffrence. Compare a multibit to a singlebit DAC's player and nobody is going to struggle hearing the patently obvious....

Instead of everyone going and listing blind tests that back them up maybe we could all try and aim to further out knowledge on what is actually going on. I agree quite happily that lots of blind tests have not worked. Maybe the fact that a blind test that works like expected isn't very interesting or newsworthy but one that doesn't is worth reporting....

John
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post #373 of 390 Old 06-13-2006, 01:15 PM
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here is an intresting link...
edit can't post links yet will post them after have done 5 posts

Another thought... You can take two motherboards from diffrent manufacturers with the same memory, cpu, chipset, hdd, psu...

However we will all agree that one will probablly benchmark better than the other. Now if all the buses use the same chipset and same frequency why is one better than the other?

After all again it is just 1's and 0's... It's a good example of two diffrent makes that do the same job with same chips but get diffrent results that in the case of a computer due to their very job it can easily measure the diffence and present them as a performance number. It's difficult to rely on the brain to act in a predictable way as a sound wave convertor and measuring device.

John
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post #374 of 390 Old 06-13-2006, 07:53 PM
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Sorry but in a lot of blind tests in magazines I have read about the listeners were blindfolded
And in a lot they weren't. Being blindfolded is not an essential part of the double blind methodology. Since your "well, people can't use their vision" theory can't account for non-use of blindfolds in DBTs, it falls apart.
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post #375 of 390 Old 06-13-2006, 08:17 PM
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[quote=mr-mac]Sorry but in a lot of blind tests in magazines I have read about the listeners were blindfolded.... You may know what you mean but it doesn't mean every blind test is conducted the same way.

Which magazines? Perhaps their protocol was not really credible to begin with and used blindfolds as yet another misdirection? So, without knowing who what where, hard to comment. The ones I read about, no such blindfold were used. RobertR also explained this DBT.

but I was merely stating with no vision it may by default change the way my brain interprets the information.

This would be easy to test with really blind people. I hear different stories from such queries. Their sight is not confusing the issues, gives them a better chance at analyzing the sound by itself.

I am only trying to premote discussion on the subject (I know what I can hear) and what I hear means there must be more to this than either side of the discussion have said so far.

Oh, discussion is great. But, there is a wealth of data out there already in psychoacoustics, an old field, and human psychology on this. Not possible for any of us to cover it all as I am sure none of us know it all what is in those libraries of learned knowledge base. Impossible.



Compare a multibit to a singlebit DAC's player and nobody is going to struggle hearing the patently obvious....

Not proved. Hearing has lots of limitations contrary to many peoples different beliefs on it.

[b]Instead of everyone going and listing blind tests that back them up maybe we could all try and aim to further out knowledge on what is actually going on. [b]


Oh, brain researchers are doing this. But, that doesn't negate the credibility and that DBT is the gold standard for discovering the truths when humans are the test instruments.



I agree quite happily that lots of blind tests have not worked. Maybe the fact that a blind test that works like expected isn't very interesting or newsworthy but one that doesn't is worth reporting....

John


Well, actually, the ones that do produce positive outcomes have been published as well. Greenberg on wire test comes to mind off hand.
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post #376 of 390 Old 06-13-2006, 08:32 PM
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[quote=mr-mac][quote=CharlesJ]
Anyway I have a theory about listening and DBT....


Sorry :D a scientific theory must have data behind it :p before it becomes a theory. I don't think you have that. :D

So my theory goes.... It's DBT's that are flawed (just a theory),

As above. ;) Maybe you have a hunch?


I know for a fact I am not influenced by brand name, price etc.

No, not a fact. Your subconsciousness has a different idea about all this. :D

and always go to a listening test and try out 3 or 4 products at length and can immediatly hear the diffrences.

Because you are biased, flawed protocol no less. Humans are predisposed to differences. 75% of the time people find differences when the same component is presented twice. This is a fact and can be demonstrated at will.

Now if so many people can't tell the diffrence in DBT's I knwo somthing strange is going on.

Yep, they cannot hear as well as some think they can. Not the fault of the DBT. No such evidence exists.


Well what if that is wrong?

Nothing if that can be proven. But, speculations don't cut it.

So what if the brain can more easily manufacture a soundstage and seperate out each individual instuments sound when your eyes are closed??? Well it may explain when we come down to small changes in audio quality why a DBT test might be flawed...

No, actually it doesn't explain it at all.

I suggest a DCT (remember where you heared it 1st). A Double concealed test... Instead of blindfolding the listner (blindfolding seems to be the common way of conducting this test probs cos it is the only way to do it with speakers) lets conceal the equipment (put both CD players or amps etc. under big cardboard boxes) and conduct the same test but with the listners eyes open...

No, blindfolding is not the common way of DBT and no, that is no0t the wat to do speakers either. You may want to investigate how speakers are tested under DBT. Harman International, NRC in Canada, Paradigm speaker maker, PBS speaker maker, etc.


It would be intresting to see how the results compare from DCT and DBT.

No difference if other protocols are followed as well.
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post #377 of 390 Old 06-14-2006, 02:04 AM
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5th reply will post the two intesting links, one pointing to trained ears being better than non trained....
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post #378 of 390 Old 06-14-2006, 02:09 AM
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post #379 of 390 Old 06-14-2006, 02:36 AM
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Quote:
Originally Posted by CharlesJ

I know for a fact I am not influenced by brand name, price etc.

No, not a fact. Your subconsciousness has a different idea about all this. :D

and always go to a listening test and try out 3 or 4 products at length and can immediatly hear the diffrences.


Yep, they cannot hear as well as some think they can. Not the fault of the DBT. No such evidence exists.


Well what if that is wrong?

Nothing if that can be proven. But, speculations don't cut it.
re. not influenced by brand name ---- as i posted before I walked out a shop with a Sony amp once because it sounded best (before arriving at shop I would not have rated most Sony products). I wasn't even going to try it but thought what the hay may as well... Low and behold it was considerably better than the amps I would have expected to sound better.... So subconciously or otherwise I wasn't wanting/expecting the sony to sound good

re. no evidence existing??? read the stereophile links above....

re. speculations not cutting it, you, as an advocate of DBT, are speculating because a number of DBT's have shown results you wanted, that it means there is no diffrence and are automatically speculating without considering or investigating further what these results mean. I am not saying the conclusion you have arrived at isn't the correct one and is the most obvious, it doesn't mean it's the correct conclusion.... The human brain isn't good at doing quick comparisons one after the other.... Think if I hold up two cards of almost identical colours you will easily tell they are diffrent. However, if I hold up one then take it away and produce another card you will invariablly fail to tell between them. Well if a DBT on similar colours doesn't work using the brain as a measuring device why then can it be any better with audio in the same test.... Which brings me back to further investigation is required.
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post #380 of 390 Old 06-14-2006, 07:21 AM
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DBT just worked for me....

Using headphones, facing the other direction I asked someone to help...

While listening I had my CD player (Pink Triangle Cardinal (clock locked to DAC) Da-capo DAC (HDCD filter), DC battery PSU.

I have just on 10 diffrent CD's with not a particularly good set of headphones Identified whether the DAC was running off mains or battery.

I could hear the change in definition of soundstage and, for want of better description, a slight sharpening of the focus on each instrument.

Now if I can tell the diffrence from HQ mains / Battery PSU then I am damn sure I can identify diffrent CD players...

So who was saying do a DBT and you can't hear any diffrences???

As far as I am concerned I can pass a DBT with out any problem with 100% success on my small limited test.

Guess it means some peoples ears or systems are not up to this test.... It doesn't mean however everyone who can't pass a DBT will be happy with a cheap system. You add up all these small diffrences in the whole chain and most people will be able to hear them....

John
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post #381 of 390 Old 06-14-2006, 08:18 AM
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DBT just worked for me....
Based on your rather sketchy description, it’s not clear that it WAS a DBT. A DBT means neither the subject OR the tester knows which is which. This is because it’s well known that the tester can communicate clues (even nondeliberate nonverbal ones) about which is which to the subject.

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Now if I can tell the diffrence from HQ mains / Battery PSU then I am damn sure I can identify diffrent CD players...
Flawed logic. There may have been an objective, real, significant difference between the two, which does NOT mean all other possible differences are audibly significant. Also, as I pointed out, it’s not clear that you did indeed conduct a proper DBT.

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So who was saying do a DBT and you can't hear any differences???
Don’t misstate what’s said about DBTs. If there are significant differences, they WILL be heard in a proper DBT. If there aren’t, they won’t be.

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As far as I am concerned I can pass a DBT with out any problem with 100% success on my small limited test.
Your “limited test†says NOTHING about your ability to pass any and all other possible properly done DBTs.
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post #382 of 390 Old 06-14-2006, 08:51 AM
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Based on your rather sketchy description, it’s not clear that it WAS a DBT. A DBT means neither the subject OR the tester knows which is which. This is because it’s well known that the tester can communicate clues (even nondeliberate nonverbal ones) about which is which to the subject.

Flawed logic. There may have been an objective, real, significant difference between the two, which does NOT mean all other possible differences are audibly significant. Also, as I pointed out, it’s not clear that you did indeed conduct a proper DBT.

Don’t misstate what’s said about DBTs. If there are significant differences, they WILL be heard in a proper DBT. If there aren’t, they won’t be.

Your “limited test†says NOTHING about your ability to pass any and all other possible properly done DBTs.
Right I was facing the opposite direction wearing headphones, the unit was covered with a cloth with the other person just instructed to press and let go of the button (under the cloth) to switch between mains and battery whenever they wanted... So neither me or him knew which was which.

Yes it was just a quick test but we stopped 10 seconds after the switch and I named whether it was battery or AC and got it right every time.

We then switched cd (got him to quickly press button a random amount of times) then did it again and checked my answer....

Ok not stricktly 100% exactly a DBT but to me it proves the two sound diffrent and I can identify the diffrence very quicly, without fail when neither of us knew whether it was battery or AC (the button is a press on/press off and is just a click that changes a circuit state (so not a switch that can be identified by it being in or out)

I'm just saying I am happy that I could identify products in a DBT with a very quick DBT-esk test.

At some point I will do a full and proper DBT but I am 100% sure I will pass it....
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post #383 of 390 Old 06-14-2006, 11:37 AM
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SP article 1: The VTL's have a rather signficant ouput impedance. If you know the impedance curve of the speakers, then you'll know where in the frequency spectrum to focus your attention. What Atkinson and company did I believe was level match at one frequency. Had they the capability or desire to level match at 3 frequencies, or insert an appropriately valued resistor into the speaker wire, the results would've been a null. It really all comes down to frequency response, distortion, and output impedance. Now this doesn't mean that any amp can drive any speaker. That's another kettle of fish.

Now, I've got no problem with training. In fact, you get your best discriminatory ability with all your senses if you undergo rigorous training. If a person scores well, as you seem to have, then it would behoove you to dig a bit deeper and do more replications to confirm your positive scores.

SP article 2: It would behoove JA then to simply become familiar with listening while blinded to the identity of the device. That is training since he feels that an unsighted session introduces uncomfortable stresses. OTOH, there may be psychological problems like OBCD or ADD. Further work is needed!

SP article 3: This has been covered in great detail in the Google Newsgroups. Do a search under the author's names and toss in Nousaine and/or Atkinson for a number of threads.

With all due respect mrmac, your stories and recollections are very vague. Being that, it makes it nigh impossible to comment thoughtfully on them. You may want to check if the output levels are the same when running your DAC with an internal PS or with batteries. OTOH, there may've been a reason why the unit was sold.

The DBT is the equivalent of the drag strip with carefully controlled conditions. It separates the men from the boys, the contenders from the pretenders. It means a person can no longer just go around telling everyone how wonderful this and that is or how they can hear certain things without difficulty. If you're not willing to take the car to the strip, then head on over to the local tavern and tell the other folks how zippy your ride is. It is perhaps the heights of irony that those who dismiss DBT's and listen to classical music are listening to orchestras where the musicians were selected under blind conditions. Turns out conductors were interjecting a fair amount of bias and rejecting people on reasons other than musical competency.

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post #384 of 390 Old 06-14-2006, 02:47 PM
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Originally Posted by Chu Gai

Now, I've got no problem with training. In fact, you get your best discriminatory ability with all your senses if you undergo rigorous training. If a person scores well, as you seem to have, then it would behoove you to dig a bit deeper and do more replications to confirm your positive scores.
Yeah you are correct. I intend to do some proper DBT tests of diffrent products as and when time/equipment allows....

The volume doesn't sound any diffrent in either of AC or DC, not to say there isn't a diffrence but both circuits work in the same way (when on AC power is still fed through the lead acid batteries)... I would say the unit is working correctly as both the AC or DC through the external battery supply are very close in quality and are considerably better than the original internal AC PSU (by the way even the original AC internal PSU has 19 seperatly regulated power lines).

I appologise for my decriptive ability, very true I am not the best at conveying exactly what I am trying to say....

Hopefully I have still added at least some valid input into the discussion.

I will report back once I set up a proper DBT of a few CD players and/or amps and see how my results look...

Thanks Again

John
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post #385 of 390 Old 06-14-2006, 02:56 PM
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edit - double post :D
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post #386 of 390 Old 06-14-2006, 04:36 PM
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if you've got a VOM and can burn some test tones, you can measure the output voltage at each of the speakers under both scenarios and you'll be able to confirm or deny matters. takes a little bit of time but then what doesn't?

"I've found that when you want to know the truth about someone that someone is probably the last person you should ask." - Gregory House
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post #387 of 390 Old 06-14-2006, 04:39 PM
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Quote:
Originally Posted by Chu Gai
SP article 1: The VTL's have a rather signficant ouput impedance. If you know the impedance curve of the speakers, then you'll know where in the frequency spectrum to focus your attention. What Atkinson and company did I believe was level match at one frequency. Had they the capability or desire to level match at 3 frequencies, or insert an appropriately valued resistor into the speaker wire, the results would've been a null. It really all comes down to frequency response, distortion, and output impedance. Now this doesn't mean that any amp can drive any speaker. That's another kettle of fish.
Hi.

Is the output impedance of the VTL amps mostly resistive? If there is a large reactive component in the impedance it seems to me that you will need to add more than a resistor to the speaker wire; one needs to be able to build an LCR circuit using the impedance curve, and I'm not sure that most people can do that.

Also, I think that if one of the amps has a large output impedance, whether purely resistive or not, the output impedance will interact with the speaker impedance and alter the frequency response in such a way that it will be impossible to level match at more than 1 frequency at a time.

Regards,
Sejin.
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post #388 of 390 Old 06-14-2006, 10:32 PM
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[quote=mr-mac]re. not influenced by brand name ---- as i posted before I walked out a shop with a Sony amp once because it sounded best (before arriving at shop I would not have rated most Sony products). I wasn't even going to try it but thought what the hay may as well... Low and behold it was considerably better than the amps I would have expected to sound better.... So subconciously or otherwise I wasn't wanting/expecting the sony to sound good

Not an indication of not being influenced one way or the other.

re. no evidence existing??? read the stereophile links above....

From John Atkinson??? What else can I say. He must be right.

re. speculations not cutting it, you, as an advocate of DBT, are speculating because a number of DBT's have shown results you wanted,

Actually, you are wrong, totally. I don't want any specific results other than facts. But, hey, what can I say. Speculation is rampant.

that it means there is no diffrence and are automatically speculating without considering or investigating further what these results mean.

No speculation involved. I know what they mean and what they don't mean.


The human brain isn't good at doing quick comparisons one after the other....

You think? The whole of science would discagree with you on it. But what do I know?

On the other hand, no one said you have to do it quickly. Some went on for month. Changed nothing.


Think if I hold up two cards of almost identical colours you will easily tell they are diffrent.

No, I'd have to scan them fast many times. But, in sight, you have the luxury of displaying those two one on top of the other. In audio, you cannot even though some try to.
I think I mentioned JJs name before, doing codec research. or the NRC that has also conducted them. One note looped for quick comparisons. In audio, that is how it is done because it works better. Just because the visual is done one way is not an indication that all other senses will follow the same way. It doesn't.

Which brings me back to further investigation is required.


Please. No one is stopping anyone. However, the people in the know seem to know otherwise and that excludes me.
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post #389 of 390 Old 06-14-2006, 10:44 PM
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[quote=mr-mac]Right I was facing the opposite direction wearing headphones, the unit was covered with a cloth with the other person just instructed to press and let go of the button (under the cloth) to switch between mains and battery whenever they wanted... So neither me or him knew which was which.

Please don't equate this to any other comparison of amps, CD players or DACS. You operated the dac on line voltage, or something, then switched to batter power?

How do you know it has the same output under battery power than main power? How did you test if you even considered it? If not tested that the output to the speakers were the same voltage to 1%, then you have no idea what caused a difference, if there is one. But, others have already pointed to some issues.
Maybe they will sound the different on battery power, so what? Maybe that DAC has design issues???
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post #390 of 390 Old 06-15-2006, 07:37 AM
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I'm not saying it's going to be perfect sjoh but often it brings it in close enough that the level differences are closer. All that little excercise points to though is that the audible differences are due to FR aberations. Nothing that's unknown and hardly the worth all the audiophile adjectives and adverbs that have been used or yet to be invented.

"I've found that when you want to know the truth about someone that someone is probably the last person you should ask." - Gregory House
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