[drez]

My guess would be lower distortion and faster transient response, maybe a well designed power supply as well.  If the amp had a coloured frequency response it would be pretty easy to measure.  I don't think I will ever spend 30 grand on an amplifier though - I will probably be old and deaf before I can afford to spend that much

 

[jnjn]

Quote:

If you were to control for those variables in constructing a DBT, how would you go about it? Maybe incorporate the switchbox at the transducer.
What's the total distortion and timing error that these variables may introduce? Are we talking less than a tenth of a db and less than a microsecond? Earlier on you discussed evidence of fine human discernment of interaural differences but admitted that there was no evidence that this had a specific effect on audibility.
Now you're ignoring a whole different field of testing. Faux AB tests have been conducted without any actual change beside presentation and the style of instruction. I'm not speaking strictly of DBT cable tests, but of the verified body of knowledge on the power of suggestion. So on the one hand we have evidence that the human mind is very picky about how it might interpret the exact same stimulus based on a variety of "mindsets" (beliefs, priming, physiological states like fatigue). On the other hand we have DBT tests (which you appear to discount outright) that fail to show positive results past well-established thresholds.
Having been to at least one concert in my life I can attest to the fact that drugs are some of the most commonly used audio tweaks and their effects are greater than those of any cable. Unfortunately I am having trouble finding any published DBT results and will have to ask the government for a grant to fund supplies for my own study.

Greisinger did some great stuff where he measured and provided information on how humans violate the "pan pot" law.  Basically, if an image is placed off center during mixdown, one would expect all of the image to be in the exact same location in space, a nice tight spread as it were.  David provides a plot showing measured results where the placement of the image is frequency dependent.  In other words, a frequency dependent horizontal smearing of the image.  He uses a third reference speaker to do this work.
 
My biggest concerns are:
1.  Other than Davids work, why has this effect not been spoken of in any literature, any testing?
2.  It is of course speaker dependent, I dont think I need to list those variables.
3.  The mixdown is system dependent.  I don't think anybody believes that the monitor setup in a studio is the same as the target system.
The most important issue to me is:
4.  Mixdown does not use interchannel temporal shifts.  Intensity only.  This is not how humans evolved.  We use both parametrics to discern image location.
 
Stereo is an artificial construct of sound wavefronts being used to fool humans into thinking a source is at a specific location.  Most testing is not designed to worry about that, but rather, just toss a whole lot of synthetic environment at us and say, can you hear a difference?
 
Greisinger at least contrasted the difference between one speaker as a source imaged correctly by a human, and the synthetic field produced by two speakers. IOW, what he did was create a true reference image, then had the subject compare the virtual location of the synthetic image with a real one.
 
This conversion from a real image to a synthetic one requires humans adapt to the different stimulus construct. How long does this take humans, is it different for each human, is it learnable, does it depend on history.
 
Think of those computer generated 3-D images.  To view the image, you have to maintain focus at the plane of the paper, yet rotate the eyes as if you are looking at an object far away.  You are defying the natural mechanism of "point and look". Breaking the automatic connection between angular positioning of the eyes and constriction of the lens.  We do it in a real environment without thinking, but can force ourselves to break the link.  And, we can clearly tell how long it takes to get the image, even practice to do it faster..
 
Listening to stereo is the exact same thing, but I do not believe we can control it.  We do not measure it.  We do not acknowledge it exists.  We do not produce program material consistent with how we hear.
 
Given all of this uncontrolled stuff, I personally cannot embrace a claim that simple listening/comparison tests are rigorous enough that the results of the test are statistically robust such that they can be applied to the general population as a predictor of outcome..
 
The interchannel timing we can discern is 1.5 uSec minimum (measured).  Within a complex soundfield, I do not know what the number is, I would expect 5uSec as a reasonable number.
 
Interchannel intensity, I've seen nothing with respect to image stability, but certainly could not rule out .1dB either.
 
Both variables, I can only provide reasonable guesses for.  Nobody I'm aware of has takent the trouble to measure.
 
I've not ignored any field of testing.  I understand expectation bias, sighted bias, wallet bias, and even bias bias..

 
Personally, I wanted the gov't to fund my personal audio testing, specifically the rigorous discernment of synthetic image placement with martini's being the controlled factor.
 
They did not respond to my repeated funding proposals...go figure.
 
If every test being done produces a null, but every test ignores human responses, does that mean they are all valid? 
 
I do not claim everything makes a difference, I question the validity of the tests.  My basic thinking is, always question.
 
I understand that proponents of everything makes a difference could possibly use my argument to bolster their stance even if their stance is inaccurate.  But should I not question because it might "aid and abet the enemy"?? (quite a few have hit me for that)
 
Sorry for the length..
 
jnjn

 

[liamstrain]

Quote:

I understand that proponents of everything makes a difference could possibly use my argument to bolster their stance even if their stance is inaccurate.  But should I not question because it might "aid and abet the enemy"?? (quite a few have hit me for that)
 

 
I don't think you should stop questioning. But perhaps there is a different way to present the question - even if it is couching them within a framework. Because of the technical specificity of what you are questioning, it very quickly moves out of the understanding of the majority population. So it may be that for one audience, you frame the questions differently, than you do for a science/engineering audience. 
 
For example. I call myself an atheist. If, however, I were speaking to philosophers, or students of religion, I would probably have to call myself an agnostic, because I do not think I can make a positive pronouncement that there is no god - there is always a very slim chance (scientific uncertainty) that there is, and I cannot logically disprove the existence of yaweh, or thor, or zeus, or any of them. Most christians, in fact, would probably have to admit they were philosophically/scientifically agnostic regarding zeus, or thor as well, under that rigorous definition.  BUT - for the layman, to better communicate my feelings on the subject where I think the odds so infinitely small - the word Atheist - while incorrect philosophically, is actually more accurate and useful in conversation with that audience - where the word agnostic is taken to mean truly undecided, or that they are equally likely outcomes - and that is not the case.

 

[jnjn]

Quote:

 
I don't think you should stop questioning. But perhaps there is a different way to present the question - even if it is couching them within a framework. Because of the technical specificity of what you are questioning, it very quickly moves out of the understanding of the majority population. So it may be that for one audience, you frame the questions differently, than you do for a science/engineering audience.

I absolutely agree.  I have this problem when I give tours or talks or presentations .  Sometimes it's 5th graders, sometimes it IVY league engineering prof's, sometimes individuals well above that.  Without the face to face, it's impossible to distinguish a 5th grader with google from a nobel laureate.  Sigh. (I like the 5th graders the best followed by the really high up theres...high schoolers, general public, and university students aren't as much fun)
 
Sometimes when I dumb it down I am accused of insulting someone's intelligence, if I don't, I'm accused of ego or strutting..  It's a no win situation..  So I don't worry about it.  (that's probably very obvious..)
 
jnjn

 

[bigshot]

[quote="Magick].. Amps, especially tube amps, can and do sound different, but the change is minor compared to changing speakers and headphones[/quote]


i was thinking of solid state amps when I said that. They're designed to adhere to a standard response, and their distortion levels are all pretty much so low you can't hear it. It's no wonder they all sound the same. They're supposed to.

 

[bigshot]

It's kind of funny that even magazines that follow the objectivist ideology once in a great while find amps that for no explanable reason sound better than other amps that spec the same or even better & even they get all gaga over them. It is actually quite rare that they do but it does happen. What seperates at least some high end amps from the rest of the pack is not nessessarily coloration but the ability to dig deeper into the soundfield & bring ou details that other amps obscure without otherwise scewing the sound in one direction or anouther.

I think it's more like the amp manufacturer dug deeper into their wallet to encourage reviewers to come up with flowery vagueries like "digging deeper into the soundfield".

I learned about the difference between amps when I was in college. My brother had a complete Macintosh system which I admired greatly, but couldn't afford myself. All I could afford was a Sanyo 50 watt amp. I was babysitting his house while he was on vacation once and I patched my amp in, bypassing his power amp and preamp. I was expecting a huge difference, but it sounded the same.

The difference was, my Sanyo amp burned out after ten years, and my brother's Macintosh system is still going strong. But I could buy a new cheap amp every ten years for a century and still not spend as much as my brother did.

 

[bigshot]

My guess would be lower distortion and faster transient response, maybe a well designed power supply as well.  If the amp had a coloured frequency response it would be pretty easy to measure.

Even inexpensive solid state amps perform well below the threshold of audibility on all those aspects. High end audio components are sometimes deliberately colored... Usually a high end rolloff designed to give suckers that "nice warm analogue sound". It's certainly measurable, but a + or - of 3dB on the response specs can hide a multitude of sins.

 

[bigshot]

Sometimes when I dumb it down I am accused of insulting someone's intelligence, if I don't, I'm accused of ego or strutting..  It's a no win situation..  So I don't worry about it.  (that's probably very obvious..)

Sometimes things that seem complex in theory are very simple in practice. You talked about stereo imaging and lost me in the dust with your science. But if you want to know about stereo imaging, I can tell you very simply where the problem lies in most peoples' systems. People have a tendency to think that speakers should be placed at roughly the width of the room. This isn't true. For normal sized rooms, the main speakers shouldn't be more than eight feet apart.

I've seen folks who spend good money on nice stereos and then completely undermine the sound by putting the speakers on their extreme right and left. Then, just to make everything neat and tidy, they shove the speakers up against a wall. Speakers need to be freestanding in the room and they should be close enough together that the sound overlaps a bit in the middle. This is what produces "soundstage". Not tiny slivers of time or micro details.

The real problem with achieving good stereo imaging has less to do with science and more to do with the arrangement of furniture that the wife will allow in the living room.

 

[maverickronin]

Quote:

I'm not attacking your statement, I'm simply wondering what physical factor might lead to an increase in perceived detail.

 
One way is to add a small amount of high frequency distortion like an exciter DSP does.  It's an interesting psychoacoustic trick but it's obviously less accurate.

 

[jnjn]

Quote:

Sometimes things that seem complex in theory are very simple in practice. You talked about stereo imaging and lost me in the dust with your science. But if you want to know about stereo imaging, I can tell you very simply where the problem lies in most peoples' systems. People have a tendency to think that speakers should be placed at roughly the width of the room. This isn't true. For normal sized rooms, the main speakers shouldn't be more than eight feet apart.
I've seen folks who spend good money on nice stereos and then completely undermine the sound by putting the speakers on their extreme right and left. Then, just to make everything neat and tidy, they shove the speakers up against a wall. Speakers need to be freestanding in the room and they should be close enough together that the sound overlaps a bit in the middle. This is what produces "soundstage". Not tiny slivers of time or micro details.
The real problem with achieving good stereo imaging has less to do with science and more to do with the arrangement of furniture that the wife will allow in the living room.

[size=12pt]You're not married, are you[/size][size=12pt]...

[/size]
 
[size=12pt]I absolutely agree.  Until the speaker/room stuff is done, complete with treatments and such, worrying about silly wires is just, well, silly.  I always defer to experts when it comes to the room[/size][size=12pt].[/size]
 
[size=12pt]Actually, the speakers and room set the stage for soundstage.  When you finally have a really hot room so to speak, then ya MAY have to worry about the little slivers of time (little to me anyway), dispersion characteristics, flatness, group delays, all that yada yada stuff.  Problem is, nobody really understands all that garbage.[/size]
 
[size=12pt]Ask a salesman or vendor who makes a living selling stuff to assist in fixing small perceived or even real defects???sheesh.  Please, here's my wallet....it was too heavy anywhoo..[/size]
 
[size=12pt]Seriously though, To me, the perfect world would be one where the equipment has been designed to eliminate all EMC issues.  Then out of the box, no hum, no noise, no buzz from lights, no clicks or pops from HVAC or fridges, and most importantly, a system with a sound that is entirely invarient to line cords, interconnects,  power conditioners, loads or progarm..  That's the way it should be...[/size]
 
[size=12pt]jnjn[/size]

 

[bigshot]

I can't get married... I'd have to get rid of all my stuff!

 

[Tilpo]

I can't get married... I'd have to get rid of all my stuff!

That's what we call 'being married to your gear'.

 

[anetode]

My biggest concerns are:
1.  Other than Davids work, why has this effect not been spoken of in any literature, any testing?
2.  It is of course speaker dependent, I dont think I need to list those variables.
3.  The mixdown is system dependent.  I don't think anybody believes that the monitor setup in a studio is the same as the target system.
The most important issue to me is:
4.  Mixdown does not use interchannel temporal shifts.  Intensity only.  This is not how humans evolved.  We use both parametrics to discern image location.

On points 3/4, it's more of a majority issue. There exist less popular approaches to both recording and playback that account for both.

Stereo is an artificial construct of sound wavefronts being used to fool humans into thinking a source is at a specific location.  Most testing is not designed to worry about that, but rather, just toss a whole lot of synthetic environment at us and say, can you hear a difference?

Yes, those studies are easier to carry out and so they dominate. Specific concerns can be allayed by a later meta-analysis that could make recommendations for novel study design. I think this hits on one of the important differences between your skepticism and that of other posters to this thread. You're pointing out the flaws in synthesizing audio image localization and it is indeed a complex field. Leaving it on the back burner for a bit, there's still value in conducting simple tests based on the tonal changes in mono or (gasp! ) panned-mono stereo.

Given all of this uncontrolled stuff, I personally cannot embrace a claim that simple listening/comparison tests are rigorous enough that the results of the test are statistically robust such that they can be applied to the general population as a predictor of outcome..

Bingo! Which is why I think it's fair to suggest that most high-end cable manufacturers' internal "studies" are even less worthwhile. This is also why it's worthwhile to suggest to people asking for advice that they stay away from cables designed by science mysticism rather than science. Finally, it is also why my skepticism leads me to conclude that the default conclusion is that psychological processes play a greater role than physical changes. Notable changes produced by cables would be far easier to find, and indeed they are, when there's a clearly audible deficit (noise, drop-outs and the like).

Personally, I wanted the gov't to fund my personal audio testing, specifically the rigorous discernment of synthetic image placement with martini's being the controlled factor.

For example. I call myself an atheist. If, however, I were speaking to philosophers, or students of religion, I would probably have to call myself an agnostic, because I do not think I can make a positive pronouncement that there is no god - there is always a very slim chance (scientific uncertainty) that there is, and I cannot logically disprove the existence of yaweh, or thor, or zeus, or any of them. Most christians, in fact, would probably have to admit they were philosophically/scientifically agnostic regarding zeus, or thor as well, under that rigorous definition. BUT - for the layman, to better communicate my feelings on the subject where I think the odds so infinitely small - the word Atheist - while incorrect philosophically, is actually more accurate and useful in conversation with that audience - where the word agnostic is taken to mean truly undecided, or that they are equally likely outcomes - and that is not the case.

Very good point. I pretty much do the same.

 

[germanium]

Quote:

I don't really see how amps would be able to increase resolution.
Resolution is mainly defined by the frequency selectivity of the basilar membrane, and the intensity selectivity of the auditory system. The resolution in terms of frequency and intensity is far greater in almost all amps, so how could an amp increase resolution?

I would argue that it is more likely that perceived increases in resolution are caused by psychological factors which in turn may be a result of e.g. increased treble response. But then it'd be easier to do it with an EQ than with an amp.
I'm not attacking your statement, I'm simply wondering what physical factor might lead to an increase in perceived detail.

Better power supply caps providing a better return path fr the signal coming back from the speakers or source. On most amps the power supply is in the direct signal path. Two amps can spec the same yet sound quite different as specs  don't tel how the amp responds to complex signals, only simple signals are used to test amps for distortion & such. The ear can in some cases pick up on what scopes miss. The biggest differences I hear with my mods is when I modify the power supplies for lower output impedance across as much of the audio band as possible, that is after D.C. coupling that is. The differences are quite huge yet frequency response plots still show the frequency response is still flatter than the proverbial pancake.

 

[germanium]

Quote:

Even inexpensive solid state amps perform well below the threshold of audibility on all those aspects. High end audio components are sometimes deliberately colored... Usually a high end rolloff designed to give suckers that "nice warm analogue sound". It's certainly measurable, but a + or - of 3dB on the response specs can hide a multitude of sins.

I know of no high end solid state amp that measures anything but flat in the audio band yet listening tels a different story though the story has nothing to do with frequency response but perceived resolution or the ability to seperate out different sounds in an extremely complex soundfield. These so called colored amps that these high end amp manufacturers are making still measure flatter than a pancake in frequency response tests yet still sound different. The reason that most, not all, midfi stuff sounds the same is that cost constraints dictate than they all use the same quality level of componants in thier amps & sources, especially powersupply & coupling caps.