The fallacy of Expectation Bias

[microstrip]

Reviewing this thread, it strikes me that measurements themselves can create an expectation bias.

Jazdoc,

Surely they can create. The measurements of some recent tube preamplifiers are so good that their owners do not need to listen critically to them anymore .They just enjoy the music and post in forums ...

 

[mep]

Reviewing this thread, it strikes me that measurements themselves can create an expectation bias.

And surely they do Doc.

 

[Phelonious Ponk]

Of course measurements can create expectation bias. Anything that sets expectations can create expectation bias.

Micro, if it's the distortion resulting from clipping that gives more powerful amps a "sense of ease," I don't know what it is. One thing it is not is universally accepted. There are plenty of people who believe very powerful amps cannot sound as good as weaker ones. I've yet to see a viable explanation for how that could be, but we hear what we hear. What I hear is that more power generally sounds better. As a non-engineer just kind of mucking about with limited knowledge and a bit of logic, lots of small clipping events would seem a pretty good explanation for the clarity of excess headroom, but "pretty good" is the best I've got. Maybe one of the resident experts has a better explanation.

Tim

 

[microstrip]

Of course measurements can create expectation bias. Anything that sets expectations can create expectation bias.

Micro, if it's the distortion resulting from clipping that gives more powerful amps a "sense of ease," I don't know what it is. One thing it is not is universally accepted. There are plenty of people who believe very powerful amps cannot sound as good as weaker ones. I've yet to see a viable explanation for how that could be, but we hear what we hear. What I hear is that more power generally sounds better. As a non-engineer just kind of mucking about with limited knowledge and a bit of logic, lots of small clipping events would seem a pretty good explanation for the clarity of excess headroom, but "pretty good" is the best I've got. Maybe one of the resident experts has a better explanation.

Tim

Tim,
Please re-read my post . I wanted to say the opposite you refer - the "sense of ease" is due to something else, not just clipping. I referred that my experiences were carried without voltage clipping, and checked with instruments.

 

[fas42]

Micro, if it's the distortion resulting from clipping that gives more powerful amps a "sense of ease," I don't know what it is. One thing it is not is universally accepted. There are plenty of people who believe very powerful amps cannot sound as good as weaker ones. I've yet to see a viable explanation for how that could be, but we hear what we hear. What I hear is that more power generally sounds better. As a non-engineer just kind of mucking about with limited knowledge and a bit of logic, lots of small clipping events would seem a pretty good explanation for the clarity of excess headroom, but "pretty good" is the best I've got. Maybe one of the resident experts has a better explanation.

Tim

OK Tim, we'll try again, although by the standards of many here I wouldn't be that "expert". Over many years I've determined by constant experiment that the quality of the power supply is absolutely crucial, as micro has pointed out. And whatever you do to make that supply "happier" will improve the sound: increase the size of everything within the supply circuit, transformer, reserve cap's, the works; change and improve the actual way the circuitry functions, the topolgy; and finally, improve the quality of the raw AC being fed to the supply.

And the reason for that? It's because the conventional supply is actually extremely crude in its functioning; yes, the text books are full of nice explanations of how it all works, with very graceful drawings of how the voltage might sag as the capacitors run out of puff, and are recharged, but it's fantasy land stuff ...

First of all, these books assume all the components are "perfect", work to nice mathematical rules. Well, guess what, they don't, and most unfortunate of all, the very way the real components, rather than the glorious imaginary ones of textbooks, misbehave is precisely such to cause real problems. But if you make the components bigger, just brute force overwhelming the deficiencies in the end will get you over the line. A crappy car with a lousy engine will eventually get through a 100mph barrier if you just keep making that poorly conceived engine bigger and bigger ...

Secondly, the way real circuits work does not present a nice "load" to the power supply; just like tricky speaker loads to power amps, if a circuit draws current from the supply in "awkward" ways then that supply will misbehave.

Thirdly, a fantasty of power supply design is that the AC coming in is a beautiful, pure sine wave. Well, sorry to say, it's a mess, and it's at the very worst just when the component's power supply tries to draw the biggest pulse of energy

All this adds up. If you model, via a computer program, what the real behaviour of the components are, under real conditions of power in and energy drawn, then it is obvious why your amplifying circuit is struggling to work correctly, because it too was designed primarily on the fantasy of having a perfect power supply. The distortion you're hearing is that of a circuit under stress, and just calling it clipping is selling the actuality of the situation well short ...

Frank

 

[Gregadd]

I wonder if Mozart or Miles Davis believed in DBT

Thankfully they both had complete faith in their technical and artistic ability and did not give a damn what scientist thought.

 

[JackD201]

Reviewing this thread, it strikes me that measurements themselves can create an expectation bias.

Ain't that the truth. Lot's of wimpy sounding amps with high power ratings out there. That is, because when you look closely they don't publish their 8, 4 power just their 8 or 4. Receivers come immediately to mind. While a watt is a watt, what we hear is not the amp alone. I like to think of it as Horsepower vs Horsepower at the wheel.

 

[Gregadd]

So what? If, and that's a big IF, there are further gains to be made in our knowledge base it will come through application of the scientific method. It will not come through application of astrology, aroma therapy, crystal therapy, tarot cards, and as is more germane to this board the egotistical claim of superhuman ability to consciously control one's biases.

What of trial and error? The applicattion of scienece remains as much an art as anything. Controlliing bias does not require 'superhuman ability" (goldedn ears?). We learn from our experience.

Franks beleif were real. My own beleif is that he should returm his records as either defective or a breah of contract.

 

[fas42]

Ain't that the truth. Lot's of wimpy sounding amps with high power ratings out there. That is, because when you look closely they don't publish their 8, 4 power just their 8 or 4. Receivers come immediately to mind. While a watt is a watt, what we hear is not the amp alone. I like to think of it as Horsepower vs Horsepower at the wheel.

It's dead easy to create impressive sound: did it myself in a normal electrical retail store. Any half decent Japanese everything but the kitchen sink main unit, driving some Klipsch speakers: instant PA system dynamics. The Klipsch have an extremely benign 8 ohm or so impedance, with 96 or thereabouts dB sensitivity, and are not fussed when you drive them hard; exactly what one of those "wimpy" receivers are happiest with. Take that combination home, bit of judicious tweaking, and it would blow a lot of "audiophile" systems into the weeds, especially from the point of view of creating realistic, and "real" sounding volume levels ...

Frank

 

[mep]

So what? If, and that's a big IF, there are further gains to be made in our knowledge base it will come through application of the scientific method. It will not come through application of astrology, aroma therapy, crystal therapy, tarot cards, and as is more germane to this board the egotistical claim of superhuman ability to consciously control one's biases.

Am I missing something or did someone on this forum actually make that claim?

 

[Gregadd]

So what? If, and that's a big IF, there are further gains to be made in our knowledge base it will come through application of the scientific method. It will not come through application of astrology, aroma therapy, crystal therapy, tarot cards, and as is more germane to this board the egotistical claim of superhuman ability to consciously control one's biases.

What of trial and error? The applicattion of scienece remains as much an art as anything. Controlliing bias does not require 'superhuman ability" (goldedn ears?). We learn from our experience.

Franks observations arereal. My own beleif is that he should returm his records as either defective or a breah of contract.

Originally by Gregadd
If the science is perfect then so would be the results.
Oriinally posted by Ron Party
Greg, it is not that science is perfect. Instead it is that the scientific method is THE method by which we study the perceptual world.

Well niether science nor its methods are perfect. WE are not scientists. WE are end users. We evaluates as end user not scientists. Frank reported his results as an end user.

Reported by Gregadd
The question is should we become Hydrogen Audio and require ABX /DBTtesting?
Reported by Ron Party
I for one am not in favor of that. I am, however, not in favor of unsubstantiated opinion which disavows the application of the scientific method to our sense of hearing.

But Ron is not that how it works? You put forth a scintific theory and someone puts it to work. The theory failed for Frank. What that means is the either theory is invalid , can be worked around or it was misapplied. Frank sugested the theory might be invalid.
Requiring scintific proof for ones opinion is exactly what Hydrogen Audio does. Maybe that is why they resort mostly to insulting each other.

 

[Ron Party]

Mark, yes.

Greg, trial and error may be part of the scientific method. But not all trial and error is reliable. Confounding factors must be properly addressed. Bias must be taken into consideration.

I can't address Frank's plethora of fantasy because it is unique to him. He has never once to my recollection posted any evidence of anything he claims and, as such, it is neither repeatable nor verifiable. This is to state nothing of the number of claims Frank has made which seemingly apply only to HTIB system (and I remain highly suspicious of all of those claims.)

As for requesting proof, look, this is a public forum. If one wants to post one's opinion, go for it. If one wants to say that Cable A produces a lower noise floor than Cable B, go for it. If one alleges something as fact, it is fair game to ask for evidence to support that allegation. If one says the reason why Cable A has a lower noise floor than Cable B is that Cable A has a red cover whereas Cable B has a blue cover, some of us are interested in learning how that is the case. I for one am here in great measure to learn from those that have greater knowledge and experience than do I.

 

[microstrip]

Just to show how variable can be this hobby:

Memo for Listening room recommendations: for stereo listening, leave side walls reflective at first-reflection points. For multichannel listening it is optional. Audio professionals may have their own preferences—it’s all right, they are just different. From a well known book of a respected author.

I recommend treating (with absorbing panels) all of the first reflection points, not just those at the side walls. from the site of a well know and respected acoustic treatment manufacturer.

Both often refer to the scientific method in their writings.No prizes for those who immediately recognize the authors.

 

[fas42]

I can't address Frank's plethora of fantasy because it is unique to him. He has never once to my recollection posted any evidence of anything he claims and, as such, it is neither repeatable nor verifiable. This is to state nothing of the number of claims Frank has made which seemingly apply only to HTIB system (and I remain highly suspicious of all of those claims.)

A very unfortunate contamination has occurred. The friend I've mentioned many times has now acquired the disease of mine, he if anything is now more fussy than I, and is applying similar strange incantations to quite respectable audio gear from Naim and Quad. The poor fellow is silly enough to now run his system at 11 to half past volumes, compared to the earlier half nine to 10 volumes and is sounding beautiful doing so; you can go outside his house and it sounds like the real deal ...

I guess I'd better bring him down gently, and let him know that a perverse brain infection is causing him to suffer from strange delusions ...

Cheers,
Frank

 

[Phelonious Ponk]

Tim,
Please re-read my post . I wanted to say the opposite you refer - the "sense of ease" is due to something else, not just clipping. I referred that my experiences were carried without voltage clipping, and checked with instruments.

I got it the first time, micro, I just mis-typed my answer. I meant to say if it's not the distortion from clipping that gives powerful amps a sense of ease, I don't know what it is. I meant that quite literally -- I don't know what it is. But I'm hoping someone can explain...

Tim

 

[Gregadd]

Bias must be taken into consideration.

Agreed. Science must first adequately define bias and its effects. Knowing that water boils at 212 degrees F is not bias. On the other hand the mind may induce vomiting from the mere knowledge that one has drank syrup of ipecac.

 

[Ron Party]

Agreed. Science must first adequately define bias and its effects. Knowing that water boils at 212 degrees F is not bias. On the other hand the mind may induce vomiting from the mere knowledge that one has drank syrup of ipecac.

Haha! Good one!

 

[JackD201]

It's dead easy to create impressive sound: did it myself in a normal electrical retail store. Any half decent Japanese everything but the kitchen sink main unit, driving some Klipsch speakers: instant PA system dynamics. The Klipsch have an extremely benign 8 ohm or so impedance, with 96 or thereabouts dB sensitivity, and are not fussed when you drive them hard; exactly what one of those "wimpy" receivers are happiest with. Take that combination home, bit of judicious tweaking, and it would blow a lot of "audiophile" systems into the weeds, especially from the point of view of creating realistic, and "real" sounding volume levels ...

Frank

Exactly what I meant by "Horsepower vs Horsepower at the wheel" Frankie.

I did build a system like you mentioned under very strict budget instructions from my Pop. I even posted it in WBF's budget section. Of course, it did have a whole lot of shortcomings that make it less than stellar. Dynamics however wasn't one of them at least............ until the loudspeaker's cabinets begin to resonate VERY audibly.

 

[treitz3]

Some people on this forum like to talk about the effect of expectation bias and the result it has on your perception of sound. The common *wisdom* is that if you think a new purchase is going to sound good (based on looks, cost, perceptions, reviews, etc.), it will sound good and meet your expectation bias. The only way to rule out expectation bias is to sit you in a chair, blindfold and gag you, and then switch your components back and forth and see if you can pick out your new component that stole your expectation bias heart.

I think if you’re the least bit intellectually honest with yourself and you aren’t deaf as a post, expectation bias doesn’t have an effect on the final outcome of how you perceive something to sound. I think expectation bias can certainly lead you to believe that a new gadget is going to sound great, but in the end it can’t fool you into thinking that something that is inferior is superior.

This point was driven home to me last night when I anxiously opened up my 4 LP box set of Armstrong & Ellington on 45 RPM 200 gram vinyl. My expectation bias whispered to me as I opened the package, “Man, this is going to sound great!” I said, “Do you think so little expectation bias buddy?” He said (it’s a “he” by the way), “Are you crazy? Just look at that 200 gram clear vinyl cut at 45 RPM on one side only. This is going to be something special.”

So my expectation bias was jacked through the roof until reality came crashing down when the needle hit the groove and I thought I was standing at the ocean during high tide. My expectation bias took an ass-whooping last night.

I guess my point is that expectation bias can’t fool me into thinking something that is clearly not true. And it works both ways. If I plug a *new* component into my system to replace something that is broken or has been sold in order to hold me over until the next great thing arrives at my door and my expectation bias tells me that the replacement is really going to sound bad, it doesn’t mean it will. Just ask my Defy 7 MKII and my Counterpoint SA-5.1 which both found new homes.

The moral to the story is never listen to your expectation bias because the little bastard lies all the time.

Mep, listen to what your ears tell you. $$$ most of the time mean nothing in the world of audio. Reviews may put a baseline of whats to be expected. Measurements are what they are. Jack donkey droppings IMO.

My expectation bias has never swayed or faltered. Things are what they are.

 

[fas42]

Exactly what I meant by "Horsepower vs Horsepower at the wheel" Frankie.

I did build a system like you mentioned under very strict budget instructions from my Pop. I even posted it in WBF's budget section. Of course, it did have a whole lot of shortcomings that make it less than stellar. Dynamics however wasn't one of them at least............ until the loudspeaker's cabinets begin to resonate VERY audibly.

Did you note my insertion of the phrase "judicious tweaking", Jack :b? My Klispch fellows didn't have resonance problems, but I'm sure myriads of audio people would have pointed accusingly at the "aggressive" treble -- typical Klipsch, they would say. And I would say, hah! - that's not a speaker problem, that's the speaker beautifully highlighting deficiencies, weaknesses in the overall system. And then I would bury my head fiddling in various parts of the setup, almost completely ignoring the speaker. By the time I finished the sound would be extremely refined, highly realistic, and still with bags of dynamics ...

It's an excellent way to go: plenty of grunt from the get go, and refine the "roughness" out. Going the other way, starting with a "refined" set of components with no balls will be much more of an uphill battle ...

Frank