"Measured Performance vs. Qualitative Appraisal"

Solidstate (amps, preamps), Tweaks, Cables, New gear, etc...

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Postby JackD201 » Thu Dec 21, 2006 11:49 am

As I said testing is needed to be able to have product consistency and quality control.

Tony ok lang yan kung DIY project na pangsarili. Eh kung super ganda ?
Eddie paano naman kami??? Hindi na kami puwedeng magkaroon. :(

Ichabod,

that "dummy ear" model is a very close guarded secret. After hearing his creations SEPARATELY my opinion is that the design goal is not neutrality. The design goal appears to be some sort of hedonistic blend of finesse, power, tonal precision, purity and harmonic richness, oh and they aren't anywhere near break-in yet :lol:. Hard to describe but as I told VD unlike the BAT that gets so admirably out of the way the Lamms do something.

I guess the analogy used is that between a very well taken photograph and a painting by Johannes Vermeer. There is an artistic vision as well as a scientific one.

This is something touched on in another thread, a very interesting one. Designers as artists as well as engineers. This is the reason I buy TAS because of the round table discussions.
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Postby planarribbon » Thu Dec 21, 2006 11:51 am

First off: a disclaimer - i am a mere consumer. i have no advanced knowledge in the "hard" sciences, particularly in acoustics.

that being said, somebody has to advocate for "the other side", i.e., the measurements.

we cannot dismiss measurable properties offhand, like they were merely "7,500-WATTS P.M.P.O!!!!" stickers on department store boomboxes. The science of acoustics and the recent advances in the physical sciences in general for the past two decades cannot be ignored outright as mere quackery in the face of the avowed subjectivism of the audiophile community and the concurrent audiophile mindset.

These forums have seen gentlemen of far greater knowledge than i describe their audio outputs as "warm", "lush", "delicate", "matapang" etc., etc. That is all very well and good.

BUT, gentlemen (and ladies), behind music, there is also science.

It does not take a Nobel mathematician to confirm that music is an equation. Certain frequencies combined that result in an equation will, when translated into its aesthetic version, result in musical sound. non-equating combinations result in noise. this is not new.

If, then, an aesthetically-pleasing result can come up out of a mathematical construct, why then are we to assume that the qualities of the reproduction chain are purely subjective?

Pure Subjectivity in the audiophile world is dangerous. Its ultimate result would be anarchy, where "every man a golden ear" is the rule. I believe applied measurements can come up with the ultimate in audio reproduction. If we have not come up with it yet, it is not because it is impossible, but it is because of the inherent limitations on the technology that we have at our disposal as of this time.

Why have we not come up with it yet? Too many factors still have to be input. the proper parameters have to be set.

To put it as an analogy, the problem that we have, is that we are trying to cut a diamond with a chainsaw. masyado pang heavy-handed, so to speak.

more later
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Postby JackD201 » Thu Dec 21, 2006 12:01 pm

Good points made there VC Planar :D Kelan tayo babalik sa Tokyo :twisted:
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Postby arnoldc » Thu Dec 21, 2006 12:16 pm

Sir jack, 6N6 natin? Nang maikasa na sa test bench yan :twisted:

Ako would study the characteristic of the device first, say tube, find a linear operating region, make it sound "subjectively" good, and then finally, pull out the instruments to measure them. Works for me.
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Postby Voltraizer » Thu Dec 21, 2006 12:36 pm

arnoldc wrote:Sir jack, 6N6 natin? Nang maikasa na sa test bench yan :twisted:

Ako would study the characteristic of the device first, say tube, find a linear operating region, make it sound "subjectively" good, and then finally, pull out the instruments to measure them. Works for me.

arnoldc you do the measuring, i'll do the listening......basta maganda pakinggan ok na ko
:lol: :lol:
in the same manner pag nagluto si mrs (assuming marunong) it's hard to quantify the pleasure derived from eating delicious food.... basta masarap...okay..ayoko lang ng vetsin :evil:
i won't bother measuring the amount of salt, sugar o kung anuman yun ratio ng ganito sa ganyan... :shock:
ang babaw!!!! :!: :?:
Suggested answers to the examination questions::
Some say measurements don't matter
1)it always matter to killer mike 38-24-35 :D


Some say Measurements must serve the Observations
2)i don't know what kind of effect meron yun measurement when observed by the killer :shock:

Some say Observations must serve the Measurements
3)Matindi ang service ni KM pag naobservahan 8)


Some even say only Measurements matter ]
4) IF .T. GOTO 1) Above :o
I always take note of the measurement of my wallet as thickness and no. of pieces of Ninoy.
No Ninoy, no audio, no software. :oops: :(
tagal na di nagpopost si KM nagpapayaman ng todo! BIGTYM!!!!
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Postby JackD201 » Thu Dec 21, 2006 12:40 pm

arnoldc wrote:Sir jack, 6N6 natin? Nang maikasa na sa test bench yan :twisted:

Ako would study the characteristic of the device first, say tube, find a linear operating region, make it sound "subjectively" good, and then finally, pull out the instruments to measure them. Works for me.


Padala ko sa iyo partner. BTW need your OPT specs so I can write Piltron na. Mukhang puwersado tayo sa custom wound.
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Postby arnoldc » Thu Dec 21, 2006 12:46 pm

voltraizer, yung 45 amp na nadinig mo, maganda measurements nun :wink:

sir jack, i'll prepare the specs na bibigay ko din dun sa winder namin.
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Postby rtsyrtsy » Thu Dec 21, 2006 1:46 pm

JackD201 wrote:I guess the analogy used is that between a very well taken photograph and a painting by Johannes Vermeer. There is an artistic vision as well as a scientific one.


Most of us can press the shutter, but this is genius manifested...

Image

Image

Sorry, OT. Si JackD kasi, ang dami kong ginagawa eh nag popost ng mga ginugusto kong i-Google. :D
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Postby jetm » Thu Dec 21, 2006 2:00 pm

Hang on guys. This thread is all over the place. I’m interested in the outcome of this discussion (specifically, more information about the measurements that Lamm and other designers use to predict the sound), so can I volunteer to try to sort it out?

We seem to be discussing “measurements” in 3 different contexts.

1. Measurements that determine whether a product is working correctly

Included here are comments from:
• Russ – proper tube biasing; not overloading the electrical circuit
• JackD201 – measurements ensure quality control
• rascal101 – measurements ensure that you are following engineering standards
• Jon Agner – measurements ensure that output values meet design parameters

2. Measurements that help determine synergy – how different products will work properly together

Included here are comments from:
• marty_e – matching cartridge output to phono stage, amplifier power and speaker sensitivity and room size
• jadis – pays attention to amp power, loudspeaker efficiency, and phono cartridge gain when assembling a system
• JackD201 – measurements as a rough guide to system matching

3. Measurements that correlate with how a product sounds

Included here are comments from:
• rascal101 – who is figuring out how to measure harmonics; when designing he sees to it that response is flat over the audible frequency range and that there are no phase shifts to distort apparent distance of sound source
• marty_e – quoting Lars Hansen saying that tonality and timbre cannot be interpreted by standard quantitative metrics
• dogears, audiofilio, botching, brady, ichabod – all saying or implying: “trust your ears”
• Jon Agner – “how does one measure music?”
• JackD201 – about Lamm’s simulations, Voecks’s set of metrics, Albert VS’s parameters; all of which provide a basis of reliable metrics upon which they then perform listening tests
• Planarribbon – that there could be a mathematical construct that can produce aesthetically-pleasing sound
• arnoldc – studies the characteristics of the device first and finds its linear operating region, then makes it sound good, and then measures (which seem to imply that he is also trying to identify measurable parameters that correlate with the sound that he likes)

Please pardon me, and do correct me, if I have misquoted or misrepresented anyone’s contribution.

I don’t propose that we limit the discussion to any one context. I did want to help ensure that comments are directed to the appropriate context.

For example, allow me to take point no. 3 further, as it seems that there are relatively new developments in this area that go beyond the familiar “objectivist vs. subjectivist” debates. Specifically:

• Lamm’s measurements. He pays independent testers to verify his amps’ measurements in terms of distortion vs. output, bandwidth, harmonic distortion, and clipping characteristics. And it would seem that those measurements enable him to predict the sound of his amps. But do tell us more, Mr. D…
• The growing debate regarding Class D amps and, in particular, the large differences in perception of the sound of the Rowland 201 amp. TAS reviewers find that it has high-frequency shortcomings. Jeff Rowland says that their own test measurements of the 201 “produce nothing that would support assertions about any such shortcoming.”
• The reputation of the Magico Mini for measuring as flat as (or flatter than) any other loudspeaker. “The net result of this fabulous on-paper performance is fabulous transparency to the source, in-room,” says jvalin of TAS.
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Postby rtsyrtsy » Thu Dec 21, 2006 3:30 pm

jetm,

Thanks for mother-henning this discussion. You've done a great job.

I'd be quite keen to push the discussion on measurements to what audiophile qualities or attributes a particular measure tries to quantify or objectify.

E.g.:

flat frequency response (set optimally given a room), low jitter, low wow & flutter = accurate?
lots of (even-order) harmonics = rich / full-bodied?
frequency range = extended?

It seems that the pitch-related virtues have lots of measures.

How about the temporal virtues like "fast/slow," or "toe-tapping."

How about the visual ones like "imaging & soundstaging."
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Postby JackD201 » Thu Dec 21, 2006 3:46 pm

Hehehehe Jetm just exposed my evil intent.

I started this thread to make a point or rather to put forth a thesis statement that just like the human genome project, there is still so much to learn about how we humans interpret sound. The boundaries of this subject defined by the telecom industry in its infancy (represented by Jon's comment on Mssrs. Fletcher and Munson) is now being pushed by the broadcast industry and ofcourse our own little nick-o-the-woods.

Again just as the genome project continues to map out our genetic structures there may come a time that hearing may be mapped out too at least to the extent of a anthropomorphic baseline.

Is Vladimir close? Maybe but most likely not as close as we would hope. Same goes for Kevin or Albert or the team at Bell Labs. Close enough to be genuine artistic interpretations colored with their own imprints but not more than that.

The clue was in the "where nobody is right or wrong" part of the thread starter. Being human qualitative observations can never be totally separated from us. It is just our nature to question,pursue and express.

In time however it may be possible to quantify these qualities and when this happens I predict a leveling of the playing field and better sound for less $$$$....for ALL music lovers.....

..............as long as we all keep open minds. :)
Last edited by JackD201 on Thu Dec 21, 2006 3:49 pm, edited 1 time in total.
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Postby rascal101 » Thu Dec 21, 2006 3:48 pm

Per what I've read, tubes produces lots of even order harmonics while SS produce odd order harmonics. However, how how do you determine if the harmonic is even or odd? Is there a reference frequency table? Where?
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Postby ichabod » Thu Dec 21, 2006 3:50 pm

Jetm this thread is on my watch list and is really spinning. It would be interesting to see some real test of scientific measurable facts and aural listening experiences on music. That's my reason for throwing musical critics into the equation to make things more compleat. After all the BBC engineers were able to design better speakers by using both ears and the science of audio to arrive at better natural sound. But they don't have the monopoly of things in this department any longer, do they?

This puts the Lamm amplifiers in a unique position. A secret "ear" plot to listen and then translate that plot into a realism that almost belies reality. Can this be something akin to the fletcher-munson curve effect on the ears? I suspect it must build around it, and something better which yes as JackD says is their trade secret. I wonder if the Americans will this time trust the "Vlady" Russian. The cold war is over. Gauging the reviews, they are!

I've only heard the comments on LAMM amps, and so far, there appears to be a convivial consensus that it sounds more natural than any. Only JackD and Keith, and some others later will tell us more. So yes, this thread will be the hottest in days to come.

So fire away!
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Postby JackD201 » Thu Dec 21, 2006 3:55 pm

Rascal

Some resource links for you even order harmonics are the even numbered ones odd are the odd numbered ones. I included a harmonic calculator.

http://www.csgnetwork.com/harmonicscalc.html

http://cnx.org/content/m11118/latest/
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Postby Voltraizer » Thu Dec 21, 2006 3:59 pm

:lol: :lol: :lol:

Hey JetM, Russ and JackD,
ligthen up, i'm just making a joke.....(not funny huh?) 8)
measuring one's wallet by the thickness or no. of pcs,
measuring recipe by the ingredients,
measuring.......nevermind

...are all OT, i apologize for the OT....
Last edited by Voltraizer on Thu Dec 21, 2006 4:07 pm, edited 1 time in total.
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Postby JackD201 » Thu Dec 21, 2006 4:04 pm

rtsyrtsy wrote:
JackD201 wrote:I guess the analogy used is that between a very well taken photograph and a painting by Johannes Vermeer. There is an artistic vision as well as a scientific one.


Most of us can press the shutter, but this is genius manifested...

Image

Image

Sorry, OT. Si JackD kasi, ang dami kong ginagawa eh nag popost ng mga ginugusto kong i-Google. :D


OT

The Girl with a Pearl Earring was one fantastic movie! Art, early photography, the alchemy of oils and dyes....Scarlet Johansson :twisted:
A must see even for non art lovers. Fell in love with Vermeers work at the Metropolitan I got caught standing inside the ropes :lol:
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Postby rtsyrtsy » Thu Dec 21, 2006 4:26 pm

JackD201 wrote:[Scarlet Johansson :twisted:


JackD, please convince me that everything else you said apart from the above actually had any real significance. :D

Seriously, who are actually at the forefront of this fields of study? Which universities / research institutes, etc.?

I was recently in Scandinavia checking out an outousrced R&D operation. One of their businesses tested things like what screen resolution (given a certain screen size, viewing distance, application, etc.) is the maximum that an unaided eye can actually still discern. They do the same for audio too, e.g. how much can they compress digital audio before the unaided ear perceives the signal as unaceptably bad.

These findings are then applied to bandwidth assignments in say an HD terrestrial or mobile television broadcast.

The other bits of the biz dealt with photonics applications in long distance ultra-broadband. Guess which parts of the business had a truly thorough due diligence from my team? :D (Hint: it's the division whose pantry ran out of pickled herring.)

Interestingly, the people that did these tests were not just telecom or broadcast engineers. They had EENT's, psychologists, ergonomics experts, etc.

I guess the point is that objective measures are the tip of the iceberg. I won't be surprised that engineers working ALONE have a snowball's chance in hell to pull something like this through.
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Postby arnoldc » Thu Dec 21, 2006 4:29 pm

rascal101 wrote:Per what I've read, tubes produces lots of even order harmonics while SS produce odd order harmonics. However, how how do you determine if the harmonic is even or odd? Is there a reference frequency table? Where?


Can't you get this from FFT?
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Postby rascal101 » Thu Dec 21, 2006 5:40 pm

No.

I'm currently using the equal temperament tuning scale as reference. The reason I asked was because I was thinking there may be other tables out there that I don't know of. The equal temperament scale lists a table of frequencies vs the corresponding notes. Based on this table, you can find out if a harmonic frequency is odd or even.

For more information regarding this http://www.silcom.com/~aludwig/The_musical_scale.htm.
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Postby JackD201 » Thu Dec 21, 2006 6:11 pm

rascal101 wrote:No.

I'm currently using the equal temperament tuning scale as reference. The reason I asked was because I was thinking there may be other tables out there that I don't know of. The equal temperament scale lists a table of frequencies vs the corresponding notes. Based on this table, you can find out if a harmonic frequency is odd or even.

For more information regarding this http://www.silcom.com/~aludwig/The_musical_scale.htm.


As is the case with any scientific study the really tough part is perfecting the correlation formulae. Kung baga how much or how little is considered "pleasurable". Ahhhhhh. The moving target where objective and subjective meet. I LOVE IT!

Russ, uh huh. Scandinavia has a bunch of state sponsored research programs then again almost all their U's are state run. Will look into the US U's Caltech and MIT have always been at it but alot coming out of all places Texas A&M. Nasa's JPL has done tons of work too. Vlady came from the Ruskie counterpart. The guys in skirts who love fermented grass juice have a nasty facility with a kick butt sound laboratory. Dang I forgot its name!!!!

Scarlet Rules!!!! :lol2:
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