[PeeeMeS]

Quote:

Originally Posted by dpippel Yeah buddy, nothing like a little condescension to make you feel good about yourself. I'm *really* done with this thread now. Later.

You misunderstood.
That wasn't condescending at all. He was praising you!
No one in the real world actually takes audiophile as a compliment.

 

[mnhnhyouh]

Quote:

Originally Posted by Snake Like a computer, tests only tell you what you are looking for. They don't tell you what you aren't. But I'll wait for the full tests, they sound cool to me. I would like to see (all) the results, too!

So lets use some of these golden eared Audiophiles as our test beds. They claim to be able to hear the difference, and that is all that is needed.

But lets do it in a double blind test.

So where are these results?

I have heard "audiophiles" banging on about burn-in for ages, but still *no* data.

I bet it stays that way.

h

 

[Snake]

Hmmm!

But I also note people making claims against "burn in"

- contradictory to scientific engineering practices -

with just as "much" (little) proof.

Some tests would be welcome.

 

[rodbac]

I'm going to support Snake on something here:

If we confirm that people can actually hear a difference between two phones, finding exactly what the ear is detecting in that case could be complicated.

Testing only for FR, for instance, might not show you anything about whether audible differences exist- in fact, I wouldn't even call it likely.

HOWEVER, it's a red herring at this point- right now, we have no reason to believe actual differences exist between a "burnt in" phone and a new one. We haven't established that, and the only way to do so is for someone who hears it to show they can discern between them under conditions where it's the only rational explanation (which means (all together now): DBT).

There's no reason to start searching for the cause of something when we're still not sure it exists. It would only open a new debate about whether any measured differences were audible.

Quote:

But I also note people making claims against "burn in" - contradictory to scientific engineering practices - with just as "much" (little) proof. Some tests would be welcome.

We can argue all day about how significant the changes in materials will be under the stresses they endure, but I think it's acknowledged that the theoretical possibility exists, even if we don't believe it's likely.

However, I suspect you know very well that science would dictate someone reject a claim in the absence of evidence. This doesn't mean the person says "it's impossible", but merely that they say "there's no reason to believe in it", ESPECIALLY when it's been shown regularly that listeners report significant differences where none exist.

I also suspect you know something else I've said about 3.2 million times but I'll ask you this instead of repeating it again: since I'm a person that compared a broken-in phone to a new one and heard no differences, what "test" would you like to see me do for you, and tell me what you think you would learn from the outcomes of that test. You don't have to be detailed about the design- just be general.

 

[Snake]

Quote:

Originally Posted by rodbac I also suspect you know something else I've said about 3.2 million times but I'll ask you this instead of repeating it again: What "test" would you like to see me do for you, and tell me what you think you would learn from the outcomes of that test. You don't have to be detailed about the design- just be general.

Frequency response, transient time response, power vs. output response across frequency sweep, THD - would be a nice start

So, rather: "what is it doing", "when is it doing it", "it is doing it properly for various inputs" and "what is it doing that it should not be"

Hmmm. What, when, where, how.

At least it a nice start. Hopefully something will show up somewhere. Most tests only check for frequency response, but one would suspect that transient time would change with the changing of the elasticity of the materials, which has not been check IFAIK. THD should also hopefully tell something

 

[rodbac]

Quote:

Frequency response, transient time response, power vs. output response across frequency sweep, THD - would be a nice start

Ok- let's say we measure all the things you're interested in and we see varying degrees of difference, but those differences are small enough for their significance to be debatable (likely).

Does that solve anything, or do you think that in the continued absence of a successful DBT the critics are still going to maintain that the theoretical possibility exists (just as before) but there is still no reason to believe in it?

Unless you find XBOX HUGE differences in one or more of those measurements, nothing is going to change, and testing for those differences would be much more complicated than simply finding someone who can identify the differences under controlled circumstances.

 

[mnhnhyouh]

Quote:

Originally Posted by Snake Hmmm! But I also note people making claims against "burn in" - contradictory to scientific engineering practices - with just as "much" (little) proof. Some tests would be welcome.

I dont believe that burn-in doesnt exist, but given the paucity of data, I am starting to suspect it is unlikely.

The burden of proof, in science, has always been on a person claiming to detect a difference.

There is good reason for this.

Suppose I make a test, human listeners, double blind. and show no difference between burnt-in and not-burnt-in. You can say that my listeners had poor ears, the volume was not high enough, or that burn-in only occurs on Wednesday, etc.

However if I do a test and come up with statistically significant results (p<0.05) showing that in a double blind test my listeners can detect a difference, the only comeback you can have is that it was that one in 20 chance popping up....

Just so as we are on the same page with statistically significant results

http://en.wikipedia.org/wiki/Statistically_significant



h

 

[Snake]

Quote:

Originally Posted by rodbac Ok- let's say we measure all the things you're interested in and we see varying degrees of difference, but those differences are small enough for their significance to be debatable (likely). Does that solve anything, or do you think that in the continued absence of a successful DBT the critics are still going to maintain that the theoretical possibility exists (just as before) but there is still no reason to believe in it? Unless you find XBOX HUGE differences in one or more of those measurements, nothing is going to change, and testing for those differences would be much more complicated than simply finding someone who can identify the differences under controlled circumstances.

But at least we will have a scientific starting point to begin explaining the human vs. burn in interactions, and can step up from that point. There are many things we have problems with defining and also explaining, but we have to start somewhere.

The problem with DBT is that it still takes humanity into account, and therefore can be discounted by those who choose to even when completed by the most accredited of participants - this has been shown throughout history, never mind the audio field. It is the difference between a "theory" and a "law" - until proven scientifically, any human-derived answer to the universe is still called a "theory". I didn't make the rules, but there they are.

Yes, the tests are complicated. But as the people who want "proof" that burn in exists will not settle for less, and therefore less is not acceptable. Scientists know the proof, as I quickly showed in the engineering website of transient behaviors - they have mathematical models to enable computations of this during the design stage of a material. Other people have experienced it for themselves with listening, watching, feeling...using their own senses, in the appropriate manner, to tell any differences.

(FWIW I am both - I knew the basic science, and have heard - all too many times - burn-in changes. As I worked in a audio store thousands of new products came our way, and over the course of (on and off) 15 years I got to use / install / demonstrate / sell the many thousands. They certainly did indeed change after initial activation - some subtle, some a bit more, but always "within their range". That is, the burn-in never made something sound so different that it was if it was a different design. The burn-in simply makes, it seems, the basic character come more sharply into focus - for good, and sometimes for bad (Harmon/Kardon Citation 21/22 "first series mainstream" preamp and amp come to mind, as well as the full "digital" SAE line. Yuck! Can we say "grain"?!)).

Those who don't believe will not accept anything but hard, "factual" evidence; therefore only scientific analysis will suffice.

 

[rodbac]

Quote:

But at least we will have a scientific starting point to begin explaining the human vs. burn in interactions, and can step up from that point.

You don't have any "interactions" to begin explaining right now that indicate any audible differences exist, though.

Precisely the same subjective differences are regularly reported when no differences exist (comparing a cable to itself, for instance). Therefore, you have to demonstrate something other than that before we can reasonably conclude there is something interesting there.

Demonstrating a 0.5% difference in THD or something isn't going to change the arguments an iota. We already know the possibility exists.

Quote:

There are many things we have problems with defining and also explaining, but we have to start somewhere.

True, but the place you need to start is demonstrating that there is something unexplained.

Quote:

The problem with DBT is that it still takes humanity into account, and therefore can be discounted by those who choose to even when completed by the most accredited of participants - this has been shown throughout history, never mind the audio field. It is the difference between a "theory" and a "law" - until proven scientifically, any human-derived answer to the universe is still called a "theory". I didn't make the rules, but there they are.

We're not trying to establish a law of nature here.

If you perform a successful, adequately designed DBT (no glaring flaws in the design) and it's repeated with similar results elsewhere, that counts as evidence that it's very likely there's something there and it will be the doubters who get the grief for ignoring it.

Quote:

Scientists know the proof, as I quickly showed in the engineering website of transient behaviors - they have mathematical models to enable computations of this during the design stage of a material.

Uh, no, those mathematical models merely show the possibility exists (LONG since acknowledged). They don't even approach "proof".

 

[mnhnhyouh]

Quote:

Originally Posted by Snake It is the difference between a "theory" and a "law" - until proven scientifically, any human-derived answer to the universe is still called a "theory". I didn't make the rules, but there they are.

This is a common misunderstanding of the way science works.

It is impossible to prove that a theory is true, and therefore there are no "Laws of Science".

It is however possible to disprove a hypothesis. Just show one exception.

One common way to demonstrate this is the "White Swan Hypothesis".

We have a hypothesis that all swans are white. We go out and look at some swans, and they are all white. Does this prove out hypothesis true? No.

We go out and look at 10,000 swans. All white. Does this prove our hypothesis true? Nope.

We sample every swan in the northern hemisphere, and every one is white. Does this prove it true? Nope.

We see one black swan in Western Australia, and our hypothesis is now proven false.

We cannont prove things true, only false. This is why scientists test the null hypothesis of no difference and attempt to show that is false.

So for burn-in, the null is no difference between burnt-in and not-burnt-in. If there is indeed a difference you can easily demonstrate with a double blind test, that burn-in exists.

h

 

[Snake]

Quote:

Originally Posted by mnhnhyouh So for burn-in, the null is no difference between burnt-in and not-burnt-in. If there is indeed a difference you can easily demonstrate with a double blind test, that burn-in exists.

Again, all easily "discounted" by the disbelievers who will say "people are gullible" during the test.

With the scientific proof your point will be the exact point - there will be (some form of) proof, therefore it will be up to the naysayers to disprove that the figures mean anything.

Which is harder for them to do for they are generally the type who only trust the "figures", anyway.

We're all on the same understanding here, we just keep missing one another's mooring lines.

 

[rodbac]

Quote:

Again, all easily "discounted" by the disbelievers who will say "people are gullible" during the test.

They can't- that's exactly what proper design removes from the equation.

I'm with you that we probably agree, but I think you're mistakenly discounting the one and only thing that can advance the idea that "burn in" exists.

 

[mnhnhyouh]

I will only believe properly conducted tests.

I have been looking for data on burn-in, and have found *none*.

I think it is an easily tested hypothesis, and the lack of data presented by its proponents surprises me.

h

 

[Snake]

Quote:

Originally Posted by mnhnhyouh I will only believe properly conducted tests. I have been looking for data on burn-in, and have found *none*. I think it is an easily tested hypothesis, and the lack of data presented by its proponents surprises me.

I'm sorry that you have had such problems finding data. It may be that most people can personally discern a "burn in" effect so simply...don't go through the trouble of measuring what they have personally experienced in real life.

Sometimes things just work out that way. "Why write...when I know??" I'm sure teachers the world over know what that is like. Humans can be lazy when they can get away with it.

It also does not make sense of a professional, published reviewer to go through all the effort of testing a non-burned in product when he knows/suspects it will change after the burn-in; that is what people want to know, the "maximum" performance, or at least what they, also, can expect personally themselves. A non-burned in product only stays non-burned in for a short time and therefore does not represent the goods you will actually live with once you purchase the product, for the life of the product.

Like I said, hard scientific data is the only thing that will help assure the hard-core naysayers.

You have never experienced burn-in personally? Buy a new pair of cans, listen for all of 2 minutes, put them down, burn in for 5 days...come back. Different sound, "quite" different yet still the same cans. I did that with my new 404's and boy, did they change after 300 hours! (300 hours?! Yeah, they're "slow"

). I only listened to them in 40 second intervals until that point and the differences were apparent, so I don't think "mental" burn in happens after 40 seconds! (I didn't have the time during the burn-in to listen longer, anyway. Too busy then).

Audioholics had a burn in test

http://www.audioholics.com/techtips/...kerBreakIn.php

where they do note, pretty much, exactly what we have talked about -

Quote:

Following initial burn in, suspension compliance would show the usual expected shift, then eventually drift back to and settle at a value something on the order of ~5% to 10% greater than than that measured pre-burn in. In this case, taking the time to burn in drivers was necessary.

Exactly the range of engineering elastic deformation that was quoted - someplace within 10%.

But that test only did frequency response and did not test transient or other responses. Shame. You would think that a more compliant driver would respond easier to a transient, and that would show up in a test.

 

[smeggy]

These arguments are a bit futile to fight with as I said in my first post that in 30 years I heard no burn-in... ever! I also said I'll believe it when I hear it, not when I see test results. Tests mean little if it's still inaudible, though to see something might finally put these debates to rest. Before burn in became popular amongst the hi-fi 'elite' nobody ever heard it. I bet it never even occured to anyone in here at the time. So is it a new phenomenon? If so what has changed from the 80's. If it's an old phenomenon, how come nobody ever noticed before?

If people claim such profound results from burn in surely everyone would hear it. Again, when one swears to hear night/day difference and another hears no change, what am I to belive? That one is tone deaf or one is deluding himself? I know I'm not tone deaf so where does that leave things?

I also remember the 80's very well and didn't like CD at all which is why I stuck with my TT until the technology improved. I also recall the same level of BS spouted about little paper strips, magic potions and shedloads of other junk said to improve SQ with absolutely zero possibility it ever could unless you changed he laws of physics, and respectible hi-fi mags were spreading this BS! Boy it sure looks silly reading these days. People will believe whatever is presented to them if it fits their perceptions, doesn't mean it's real.

At least with headphones there is some possibility that break in (not burn in) will occur due to them being mechanical devices, but even that possibility is small as these devices are designed to stay the same to keep them working properly and within spec.

Who knows, maybe I am tone deaf after all. Maybe I don't listen quite intensly enough. Maybe my recallections of what something sounded like a week ago are too unreliable. Maybe I'm not a *gulp* true audiophile!

Who knows? Who cares!