Blind Listening Tests & Amplifiers

[nw_avphile]

Originally posted by carlosfm
I assumed tha you were demonstrating or trying to sell something to the Bryston man...

He believed there were "huge audible differences" between mass market receivers and his multi thousand dollar 2 channel separates. I honestly didn't know how the Onkyo would stack up against the Bryston gear in a blind test but I knew it measured well. I also knew the Bryston gear measured very well, so I took the Onkyo receiver out of my bedroom sytem and took it to his place. It was more an experiment than anything else. I'd never done a blind test with anything quite so "low rent" before.

Originally posted by carlosfm
Blind tests are made in a way that people know they are goind to listen a group of amps, for example.
They don't know what exactly they are going to hear.

I agree that is done in some kinds of blind studies, but I've never seen, read, or heard of it being done with audio gear. If you check the references I listed in the previous post, you'll learn the listeners are always allowed to become familiar with how the gear sounds first in "sighted" tests--i.e. they know what A and B are and what they sound like. The "blind" part is in identifying "X'.

Drug studies are another example. They're considered double blind but the people participating still know they're either getting a drug to treat a particular condition, or they're getting a placebo--they just don't know which.

Unlike say wine tasting, where you're trying to rate multiple wines against each other (i.e. place them in order), with the sorts of blind studies we're talking about here, we're only trying to determine if a difference can be detected. If anything, it gives the listeners an advantage to know what A and B are as they're more likely to know what sorts of things to be listening for. Yet they still fail to often hear a difference where amplifiers are concerned.

Originally posted by carlosfm
As for the op-amps, I changed it on my amp, one day at nigh.
The next day I was hearing to a Ben Harper CD, and my wife (not an audiophile!) came into the room and asked me:
"What have you done? Have you bough something? It's playing much better". Do you want a better blind test?

Yeah I do. Wives say a great many things to humor their husbands (and visa versa)--especially if they know they've been tinkering around with something (and they usually do). It's part of being a couple. It's not a lot different than telling your wife "you look nice, did you change your hair?" when in reality her hair looks pretty much the same as always but she just finished getting ready to go out and you know she likes hearing that. Further, even if you ask a total stranger if something sounds better or worse, they have a 50% chance of telling you what you want to hear even if they're just guessing. So your wife's comment proves nothing.

[SY]

Unlike say wine tasting, where you're trying to rate multiple wines against each other (i.e. place them in order), with the sorts of blind studies we're talking about here, we're only trying to determine if a difference can be detected.

Slightly OT, but that's not exactly correct. In analytical wine tasting, there are all sorts of methodologies (including something very much like ABX), depending on what you're trying to test. For example, the analytical tasting we ran yesterday was to determine if there was any difference between two brands of corks. No "ranking," just the simple question of "is A perceptively different than B?" (For you sensory research geeks, we use triangle tasting, multiple trial, forced-choice to answer these kinds of questions)

The difference in sociology is fascinating. When no difference was discerned, the tasters and winemakers didn't invoke goofy left-brain vs. right-brain hypotheses, nor did they complain that the test setting was unnatural, nor did they whine that the pressure of the test obscured their ability to distinguish the two wines. They merely said, "Hmph, if there's any difference, it's too small for us to perceive, so this is a variable we don't have to worry about."

[nw_avphile]

Originally posted by Brad Kizer
Very interesting thread...I'm not about to debate what someone else hears or may think they hear. Try this. Pick up a book on psychoacoustics. Some of what you find will suprise you.

Our hobby is filled with hype. The trick is (in my estimation) to be able to separate fact from fiction.

I couldn't agree more! The best tools seem to be blind listening and the null difference test for amplifiers (and a few other areas where it can be applied). And it's not just hype, a lot of it is pure myth--stuff that gets spread by word of mouth and, because of the power of suggestion, others start "hearing" the same sorts of things so it become "true". I've been there.

Originally posted by Brad Kizer
About the only thing I'm sure of (for me anyway) is that if you are testing amps it would be wise to have a control amp. Take the second amp, make your mods and listen having your assistant switch (blind) between the two.

I've done exactly that, and near the beginning of this thread mentioned advising a friend to do the same. He had an Adcom power amp that he wasn't happy with and was building something better. I suggested he use the Adcom as his reference and then do blind tests against it as he tweaked his DIY amp. The only problem is he could never tell them apart when someone else was doing the switching! That's not to say they were identical, but for his ears, and in his system, the Adcom proved to sound every bit as good as the high-end amp he built.

For folks who like "euphonic distortion", I think the above technique is especially useful as it gives you a known (presumably more accurate) reference to compare changes to as you tweak your low NFB, single-ended, or otherwise inaccurate amplifier.

Please, if you would, let us know your blind listening results with your reference amp and various tweaks!

[carlosfm]

nw,
I did that op-amp change one day, very late at night.
Nobody saw me doing it, everybody was sleeping.
I believe she was sincere when she asked that, because she was really surprised.
More than that, I believe, and it's scientifically proved, that women can hear better than men.
And if it's a non-audiophine, non-"golden-ear" that asks you that, more confident you feel.
I was shure it was much better before she asked.
But even deaf people could hear the big difference it made to the sound (for the better).
Well, I don't want to discuss wives, I just meant it's a neutral oppinion.
Comparing crap op-amps with good ones is like comparing cheap AV receivers with Krells or Levinsons.
Not do speak Halcros.
Have you heard one?
I did. For hours. I could't stop.
It's very good.
And it's Australian.
It's soooo so good that even blinded I could tell if you changed the amp .

[mikek]

Originally posted by Fantastic
Hi Mikek,
You missed the point. I should not be saying anything about your vibes because that would be categorising you. That would be wrong as it would have my own bias . I can only watch others and see how much I need to improve myself - see what the others are doing wrong and avoid doing it myself.
The world is a mirror of sorts. So what you throw out at it gets thrown back at you. Sometimes other things get thrown back at you - ignore that.
Aren't we digressing too much from this thread ? Of course it is about the 'tone of replies' that started this in the first place.

Ok..

[nw_avphile]

Originally posted by carlosfm
But even deaf people could hear the big difference it made to the sound (for the better). ...

Comparing crap op-amps with good ones is like comparing cheap AV receivers with Krells or Levinsons.

When it comes to op-amps, 99.5% of the music people listen to has already passed through dozens of "crap op-amps"--at least if you consider $0.50 parts like the 5534 "crap." What difference can one more cheap op-amp make out of 30 or 50 of them in the signal path? You might want to read this post:

http://www.diyaudio.com/forums/showt...367#post149367

Originally posted by carlosfm
Not do speak Halcros.
Have you heard one?
I did. For hours. I could't stop.
It's very good.

Where did you hear the Halcro? Were you lucky enough to have one in your own system? You might want to check out this post:

http://www.diyaudio.com/forums/showt...481#post150481

[Fantastic]

Hi Mikek,
Before I close this topic I should add that your attitude is healthy.
You must inquire about what others perceive about you either by asking or by observing how they respond to you. That way you could possibly bypass the'veil' of your own bias about yourself. That way you can understand what you really are - something very difficult to do and sometimes very difficult to accept !
Like they say - can you recognise the person you see in the mirror ? Not as simple as it looks.
A word of caution - always remember that getting an opinion is easy - getting a ( relatively ) unbiased honest one is tough.

[carlosfm]

nw, that story is old (many op-amps, mixing desks...), but doesn't get me.
If you have a disc that has very good sound, what difference does it make to know how many op-amps has the recording passed through?

I heard the Halcros on a portuguese distributor, and it's still there on the big demo room.
I have a friend there and he called me (and also their best customers) right away when they received the Halcros.
We had all the time we wanted to hear it.
No, I can't afford to have them, I would have to sell my house .

[mrfeedback]

Originally posted by nw_avphile
So your wife's comment proves nothing.

More of your consistent negativity.

I find women's hearing to be extremely discriminating, and if they like a sonics change they will say so, and if not they will say so too.
They typically have no concern about nursing egos when it comes to sounds in my experience.

Ever noticed that women can monitor several conversations at once in a crowded room ?.
Ever notice that most women do not expose their ears to machinery noise ?.

My GF is the director of a sixty place child care center, and she tells me that she can instantly identify the cry of any child in the center from her office.
Women are typically not clouded by brochure specifications or theory, and instead listen with their ears and not their knowledge.
Ever spent any time with a female violinist ?.
I have and find these peoples to have extremely fine sonics discrimination skills, and rather better than most men.

Mr nw_avphile, it seems that your hearing skills are not up to scratch.

Eric.

[jcarr]

Sy:

>The difference in sociology is fascinating. When no difference was discerned, the tasters and winemakers didn't invoke goofy left-brain vs. right-brain hypotheses, nor did they complain that the test setting was unnatural, nor did they whine that the pressure of the test obscured their ability to distinguish the two wines. They merely said, "Hmph, if there's any difference, it's too small for us to perceive, so this is a variable we don't have to worry about."<

The big Japanese electronics manufacturers that I have worked with showed pretty similar attitudes when it came to listening, measuring, and deciding what went into their products or not. When you are a manufacturer, you want your own costs and PITA factors to be as small and painless as possible, regardless of where the final retail price may end up.

regards, jonathan carr