Why you can’t trust measurements

[rbbert]

I suspect JA makes more measurements than he publishes in Stereophile; he might well be amenable to a suggestion by you as to which additional measurements would be worthwhile to include in print (IME he has been very open to this type of feedback).

Textbooks are only as good as the evidence they use, and you know as well as I that 90-100 years ago engineers in any field were more likely to accept and use empirical data as fact rather than as observation; even today the distinction between observation (empirical data, no matter how voluminous it might be) and evidence (facts gathered using the scientific method) is often blurred in engineering, occasionally with disastrous results (not so much in electrical engineering, more often in civil/mechanical and chemical engineering).

 

[nicoff]

I suspect JA makes more measurements than he publishes in Stereophile; he might well be amenable to a suggestion by you as to which additional measurements would be worthwhile to include in print (IME he has been very open to this type of feedback).

Textbooks are only as good as the evidence they use, and you know as well as I that 90-100 years ago engineers in any field were more likely to accept and use empirical data as fact rather than as observation; even today the distinction between observation (empirical data, no matter how voluminous it might be) and evidence (facts gathered using the scientific method) is often blurred in engineering, occasionally with disastrous results (not so much in electrical engineering, more often in civil/mechanical and chemical engineering).

What?! Empirical data being used in civil engineering as opposed to evidence gathered using the scientific method? Are you an engineer??

 

[AJ Soundfield]

I play one on TV

 

[brad225]

I play one on TV

I thought that was you AJ. Weren't you wearing the blue and white cap in the cab of the locomotive.

 

[rbbert]

What?! Empirical data being used in civil engineering as opposed to evidence gathered using the scientific method? Are you an engineer??

Father, brother, uncles.. they all have/had horror stories about this.

 

[NekoAudio]

Are there measurements which can indicate which of those sonic [smooth, full-bodied, "holographic", detail, transparent, crisp] characteristics are emphasized (or not?)

It depends on what people really mean when they use those terms, but generally yes there are some measurements that can translate onto those characteristics. An easy one would be transient response, since the faster something can start and stop playing a note, the more crisp or detailed something will likely sound. The more harmonics present, the more full-bodied something will likely sound.

 

[AJ Soundfield]

I thought that was you AJ. Weren't you wearing the blue and white cap in the cab of the locomotive.

Nah, I was sitting behind a studio recording console, laughing while making an electronic stereo construct based entirely on EE Blumleins patents.
That when transduced by audiophiles, becomes mystically unmeasurable.

cheers,

AJ

p.s. Say Hi to Phil for me. He was so smitten by the cardioid bass planars he heard at my old Channeside Loft that he rolled a giant version of his own, after much correspondence. Haven't heard yet but hopefully will soon, I'm sure they will sound great.

 

[nicoff]

Father, brother, uncles.. they all have/had horror stories about this.

So... you are not an engineer, and what you said is just hearsay.

 

[brad225]

p.s. Say Hi to Phil for me. He was so smitten by the cardioid bass planars he heard at my old Channeside Loft that he rolled a giant version of his own, after much correspondence. Haven't heard yet but hopefully will soon, I'm sure they will sound great.[/QUOTE]


That's funny you should mention that. We were talking about my amps upcoming alterations and the subject of engineering. Your name came up and his conversation wafted poetically about listening to your speakers at the loft. Then then went on to say, all of a sudden all he could focus on was the quality of the bass from your cardioid bass creation.

 

[jmusica]

@AJ, sounds like we were neighbors: "at my old Channeside Loft". I lived at Victory Lofts until a few months ago.

 

[rbbert]

So... you are not an engineer, and what you said is just hearsay.

I didn't know we were in court. When one of us quotes a textbook or gives a web link, this is also hearsay. I don't know about you, but I have not found any reasons to distrust my family's knowledge or opinions. As an interesting aside, though, my father strayed from his scientific roots in his later years, reverting to empiricism (which is how people govern most of their behavior); fortunately this was well after he retired from engineering.

In any case, history is replete with examples of engineering gone astray, especially prior to the 1950's (the Radiotron Designer's Handbook is from that era)

 

[AJ Soundfield]

@AJ, sounds like we were neighbors: "at my old Channeside Loft". I lived at Victory Lofts until a few months ago.

Yep, you've probably forgotten our PMs. And I'll still be at Flexpo every year, if alive.

cheers,

AJ

 

[atmasphere]

In any case, history is replete with examples of engineering gone astray, especially prior to the 1950's (the Radiotron Designer's Handbook is from that era)

GE did a study in the 1960s that showed humans were relatively insensitive to the 2nd harmonic and would tolerate quite a lot, but would not tolerate much of the higher orders at all, verifying the Radiotron Designer's Handbook in this regard.

However you can prove the sensitivity to yourself with simple test equipment. Nothing about the RDH was controversial in this regard. You seem to be exercising a Guilt by Association fallacy here. The math in that ancient tome has not somehow gone off for lack of refridgeration... At any rate if you doubt the RDH, prove it for yourself instead of the handwaving.

 

[rbbert]

GE did a study in the 1960s that showed humans were relatively insensitive to the 2nd harmonic and would tolerate quite a lot, but would not tolerate much of the higher orders at all, verifying the Radiotron Designer's Handbook in this regard.

However you can prove the sensitivity to yourself with simple test equipment. Nothing about the RDH was controversial in this regard. You seem to be exercising a Guilt by Association fallacy here. The math in that ancient tome has not somehow gone off for lack of refridgeration... At any rate if you doubt the RDH, prove it for yourself instead of the handwaving.

You rather misunderstand my points (and perhaps I do yours as well). As to "proving" it, that's not really possible for one person (listener) to do. I could convince myself that it is true for me, but that is kind of my point. A careful listener with good hearing and discrimination (and in my experience this unfortunately applies to few "audiophiles", even reviewers) can learn a lot about his own preferences, which is all that matters when choosing his own components. However, this doesn't "prove" anything in a more general sense, or in the sense of "evidence" as verified by experimentation and appropriate analysis.

I would like to read about more investigation into why 2 amplifiers (for instance) which measure similarly in whatever ways one deems relevant often still sound different, and what measurements might better explain this.

 

[W9TR]

Rob,
A good place to start exploring amplifier sound is here:
The Carver Challenge | Stereophile.com

Also I posted a white paper in the Measurements and DSP section of this forum called Multi-Dimensional audio. It’s now years old but still very relevant.

Fun stuff.

 

[rbbert]

Rob,
A good place to start exploring amplifier sound is here:
The Carver Challenge | Stereophile.com

Also I posted a white paper in the Measurements and DSP section of this forum called Multi-Dimensional audio. It’s now years old but still very relevant.

Fun stuff.

I've been reading Stereophile and TAS since their first issues, and a variety of AES papers over the last 25 or so years (I don't have access to all their papers).

 

[nicoff]

Rob,
A good place to start exploring amplifier sound is here:
The Carver Challenge | Stereophile.com

Also I posted a white paper in the Measurements and DSP section of this forum called Multi-Dimensional audio. It’s now years old but still very relevant.

Fun stuff.

TL;DR? Thirty seven years ago, Bob Carver proved to the best known audiophile of that time (J, Gordon Holt) that it was possible to make an inexpensive (solid-state) amplifier sound like one (a tube amp no less!) that cost many times more. He did it using tools and measurements.

Yet today, nearly 40 years later with better understanding of the matter and with more precise measuring tools available, there are folks that still only trust their ears. Go figure!

 

[AJ Soundfield]

I would like to read about more investigation into why 2 amplifiers (for instance) which measure similarly in whatever ways one deems relevant often still sound different, and what measurements might better explain this.

Often?? Name one such non-imaginary, controlled instance. Unless you mean this type measurement
Just a moment...

 

[W9TR]

I've been reading Stereophile and TAS since their first issues, and a variety of AES papers over the last 25 or so years (I don't have access to all their papers).

The two articles I mentioned may help answer the question you asked in an earlier post. The first is just a fun read. Let’s make any amplifier sound EXACTLY like another, shall we? What fun. The second one explores how extended measurement methodologies (exotic when the paper was written, very commonplace now) can be used to more accurately characterize equipment.

Add to that more recent work on the perception of distortion and you might conclude that this is a solved problem.

Or you might not. Either way, it’s ok. It’s a fun hobby because everything is not cut and dried.

I would like to read about more investigation into why 2 amplifiers (for instance) which measure similarly in whatever ways one deems relevant often still sound different, and what measurements might better explain this.

 

[TheGemState]

TL;DR? Thirty seven years ago, Bob Carver proved to the best known audiophile of that time (J, Gordon Holt) that it was possible to make an inexpensive (solid-state) amplifier sound like one (a tube amp no less!) that cost many times more. He did it using tools and measurements.

Yet today, nearly 40 years later with better understanding of the matter and with more precise measuring tools available, there are folks that still only trust their ears. Go figure!

It is also surprising there are folks that only trust measurements.