[TheVinylRipper]

You have a pair of different components hidden behind an acoustically transparent barrier and arranged in such a way that it is possible to instantly switch from one to the other component. You will also have taken pains to ensure that the volume levels between the different components are as similar as possible within the limits of your instrumentation.

The test subject and the person administering the test have no idea which setting of the switch is related to which component under test.

The subject is asked if they can tell any difference in the sound quality from one switch setting to the other and if they can, then which setting is of superior quality.

Again, neither the subject nor the test giver are aware in any way of which switch setting is choosing which component.

You run the test multiple times for each subject with multiple subjects while recording the answers to the question at hand.

You also run a series of tests in which the switch setting do nothing, there are no changes at all and record the answers to those tests, again without the knowledge on the part of either subject or tester as to what the settings of the test switch might control.

Only after testing is completely finished is it revealed which components were related to which switch settings and what the answers to the questions by the test subjects are.

That in a nutshell is double blind testing.

It is done all the time in cases far more serious and far more difficult than evaluating audio equipment, specifically testing of drugs.

 

[esuko]

Hello


I recently became a member of head-fi. Beginner as i am, my toughts were to make a comparision between different configurations to answers to the question of fellow beginners.

My idea was something following:

Headphones to test:
PortaPro, HP890, HD595 and HD650

Amps:
integrated soundcard, Yamaha RX-V650(HT amp) and Corda HA-2 mkII SE

Sources:
integrated soundcard, RX-V650 D/A chip and Stello DA100

But i guess my test would have no walue. Since i'm sure my integrated soundcard could deliver bellow 1% distortion for HD650.
If i can not hear the differences between 1% and 0.5% distortion then i'm sure i can not hear difference between any sources, right? Speaking of sources why none has brought up the difficulty of proving technically the differences in sound character that different cd players produce.

But hey, atleast vinyl players should sound different. Masses of the moving parts, resonances, tracking capability,... in vinyl player should guarantee difference in sound. It's so much easier to prove things in the realm of Newton.

But 0 and 1 do not tell so much to common people. Luckily i'm being educated as a computer engineer and definetly OP-amps, distortion, 0 and 1 have become familiar.
Then why a scientifically oriented student is laying money on equipment having bellow 1% distortion. Well, before i can stuck a measurement device into human brain and collect all the data that is happening there. I´m going to stay on middle ground here.

Happy listening to everyone may your measurement device be ears or oscilloscope!!!

 

[TheVinylRipper]

Hello Esuko,

You might be interested in taking the test I link to below..

http://www.klippel-listeningtest.de/lt/default.html

 

[esuko]

Hello

I took it. With little success

Oh and i have also a Duel 505-3 vinyl player so thumbs up on your vinyl ripping. Thinking that i should do the same to my most precious records.

 

[kwkarth]

Quote:

Originally Posted by TheVinylRipper /img/forum/go_quote.gif You have a pair of different components hidden behind an acoustically transparent barrier and arranged in such a way that it is possible to instantly switch from one to the other component. You will also have taken pains to ensure that the volume levels between the different components are as similar as possible within the limits of your instrumentation. The test subject and the person administering the test have no idea which setting of the switch is related to which component under test. The subject is asked if they can tell any difference in the sound quality from one switch setting to the other and if they can, then which setting is of superior quality. Again, neither the subject nor the test giver are aware in any way of which switch setting is choosing which component. You run the test multiple times for each subject with multiple subjects while recording the answers to the question at hand. You also run a series of tests in which the switch setting do nothing, there are no changes at all and record the answers to those tests, again without the knowledge on the part of either subject or tester as to what the settings of the test switch might control. Only after testing is completely finished is it revealed which components were related to which switch settings and what the answers to the questions by the test subjects are. That in a nutshell is double blind testing. It is done all the time in cases far more serious and far more difficult than evaluating audio equipment, specifically testing of drugs.

Thank you, I do know what DBT is, how it's administered, and how it's documented.
The switching apparatus, the source material, etc. typically corrupt the purity of the environment, often obscuring, in part or in total, the differences between the equipment under consideration. The deleterious effect of of this ignorance is very real. I'm not talking about drug testing here sport, I'm talking about DBT testing of audio equipment.

 

[Hi-Finthen]

With all due respect sir:

My amp history is in my profile, and I had two and three present at a time. There were both subtle and gross differences between each of these amps noted both in quick switching and long term usage which is the most important test for nuanced listenability over a wide assortment of material played. In fact the correlation of which was better, in audiophile terms of presented frequency balance, impact, tone, resolution,clarity, 2&3D soundstaging(headstaging) & width, separation of instruments and imaging was in fact inline with their cost. Cost which is NOT simply the retail price of their parts count, but design and implementation, which in fact increasingly does include better housing and structural integrity!

Likewise my evolution with sources afforded much the same lessons learned here! I will agree that the diminishing returns factor kicks in fairly early, but that is hyper subjective to true hobbyist here, because after spending quality time with a higher end piece and its listening pleasure, it is horrific to return to a lesser cost component.

The front end changed in very positive ways what i was experiencing with the transducers which remained steady state. The all simply sounded better and one, the DT-990 went from being for sale to one of my favorites to listen through. There was NO mistaking these facts here, and I sincerely believe more could be learned from this personal narration path of Head-Fi audio evolution, than the computation of what you choose to conclude based upon others writings and your asking readers to conclude what they choose, IME, VR.

BTW, many of us do choose to listen to older recordings (eg. Ray Charles, The Atlantic Years), and find that higher end DACs and AMPs are necessary and do turn this particular recording, for instance, from unlistenable to an experience of a beautiful thing to behold, same transducers used!!!

There is nothing subjective to this experience, but this is why you have a hard sell to people who have experienced differently than your propositions no matter how well you believe in the scientific testing posted here and your analysis of what all that concludes!

With all due respect to the science, presupposed

 

[TheVinylRipper]

Quote:

Originally Posted by kwkarth /img/forum/go_quote.gif Thank you, I do know what DBT is, how it's administered, and how it's documented. The switching apparatus, the source material, etc. typically corrupt the purity of the environment, often obscuring, in part or in total, the differences between the equipment under consideration. The deleterious effect of of this ignorance is very real. I'm not talking about drug testing here sport, I'm talking about DBT testing of audio equipment.

The effects of drugs on people are far more subtle and far more serious than audio equipment.

The test subject could easily be allowed to choose their own source material.

You may shout if you wish, the fact remains that double blind testing is an effective way to separate reality from imagination.

Any objection you can raise I can easily find a way to work around.

You appear to be ignoring the fact that it is science and engineering which create the audio equipment that you so treasure.

If science and engineering can be used to create a product then why may they not be used to test the very same product?

 

[TheVinylRipper]

Quote:

Originally Posted by esuko /img/forum/go_quote.gif Hello I took it. With little success Oh and i have also a Duel 505-3 vinyl player so thumbs up on your vinyl ripping. Thinking that i should do the same to my most precious records.

As the introduction to the test states, hearing distortion can be learned at least to some extent. Try some more and see if your score improves.

I do find it illuminating that those criticizing me for my objectivist approach do not take the test, or at least if they do then they do not reveal their scores.

 

[Febs]

Quote:

Originally Posted by kwkarth /img/forum/go_quote.gif The switching apparatus, the source material, etc. typically corrupt the purity of the environment, often obscuring, in part or in total, the differences between the equipment under consideration.

If a simple switching mechanism can sufficiently obscure the differences among amps to invalidate a double-blind test, doesn't it stand to reason that distortion in the transducers could do so as well?

 

[kwkarth]

Quote:

Originally Posted by TheVinylRipper /img/forum/go_quote.gif The effects of drugs on people are far more subtle and far more serious than audio equipment.

Ah, but the ignorance of the test designers for audio is far more profound.

Quote:

Originally Posted by TheVinylRipper /img/forum/go_quote.gif The test subject could easily be allowed to choose their own source material.

That's only one part of a very large equation with many variables.

Quote:

Originally Posted by TheVinylRipper /img/forum/go_quote.gif You may shout if you wish, the fact remains that double blind testing is an effective way to separate reality from imagination.

When it's conductred properly, which it rarely is for audio. Who's shouting? Some people seem to be able to hear what I'm trying to say.

Quote:

Originally Posted by TheVinylRipper /img/forum/go_quote.gif Any objection you can raise I can easily find a way to work around.

Ignorance has no limitations.

Quote:

Originally Posted by TheVinylRipper /img/forum/go_quote.gif You appear to be ignoring the fact that it is science and engineering which create the audio equipment that you so treasure.

Au contraire, my friend, it is I who am sounding the alarm regarding those who attempt to cloak their willful ignorance b'neath the guise of the "scientific" method in order to produce data to fit their presuppositions.

A true and properly conducted DBT would yield different data.
Quote:

Originally Posted by TheVinylRipper /img/forum/go_quote.gif If science and engineering can be used to create a product then why may they not be used to test the very same product?

It can be and shoould be, but we have to properly apply the rigors of proper control and administration. We cannot allow ourselves to obfuscate the whole truth in order to prop up half cocked theories.

 

[kwkarth]

Quote:

Originally Posted by Febs /img/forum/go_quote.gif If a simple switching mechanism can sufficiently obscure the differences among amps to invalidate a double-blind test, doesn't it stand to reason that distortion in the transducers could do so as well?

I absolutely agree and in fact, have observed that effect myself with what I thought were some very revealing transducers. I was surprised to find they weren't as revealing as I had previously thought!

 

[TheVinylRipper]

Quote:

Originally Posted by kwkarth /img/forum/go_quote.gif Ah, but the ignorance of the test designers for audio is far more profound.

And you know this how?

Take the test, let us know how good your ears are.

http://www.klippel-listeningtest.de/lt/default.html

 

[esuko]

Hello Vinyl ripper


I will state that i got -15dB on the test. Very bad result indeed.
I wanted to also put some more personal toughts and experiance of distortion from DIY speaker building.

People hearing distortion perceive it as volume. Higher amount of distortion the louder.

Distortion matching can be a real pain.
Even my test results vere not good. I found making crossovers for speakers difficult because of different distortion levels of drivers.
This effects that other driver is considered sounding "brighter" even thought frequency measurement is flat. This all makes also some people find more "detail" from a speaker that is distorting more in the upper frequence range.

Many hifi manufactorers aim is not total lack of distortion. Because it is impossible but rather living with it and using it as a tool creating different sound characters.

People wanting to learn more about technical side of hifi i would highly recommend the page of Siegfried Linkwitz:
http://www.linkwitzlab.com/

 

[TheVinylRipper]

Hi Esuko,

These days I wouldn't even consider making a passive crossover, they are hard to design and even harder to get right due to all the interactions with driver impedances, resonances and who knows what else.

For maximum sound quality I would go for a separate amplifier for each driver and either an active analog crossover or even better a digital crossover.

There is so much processor power available today at such ridiculously low prices that it simply doesn't make sense to go the analog route any more. You could build a digital crossover combined with with an amplifier (except for the driver MOSFETS) into a single sixteen pin dip ic and almost all the work would be writing the software, much of it available as already written libraries which you simply combine as you see fit.

If you use a reprogrammable unit, crossover changes would be as easy as squirting a few bytes of code into the microprocessor firmware and running it again.

High value precision inductors and capacitors are *expensive*, microprocessors are cheap and getting cheaper every day.

 

[JadeEast]

Quote:

If science and engineering can be used to create a product then why may they not be used to test the very same product?

http://sound.westhost.com/sim.htm