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Old 15th February 2012, 11:19 PM   #2421
a.wayne is offline a.wayne  United States
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Quote:
Originally Posted by GloBug View Post
Luna 2 was a Russian object that landed on the moon almost 10 years before the USA.

Give credit were credit is due. It was the GERMANS who put a man on the moon.

You didn't really think those guys are from Huntsville Alabama did you?

The pretzels and the funny shorts should have been your first clue.
Nor Canaduh ! ...............

OOH my composers ! What would we do without em, I'm sure you can dig deeper than this Jacco ......
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Old 15th February 2012, 11:24 PM   #2422
tvrgeek is offline tvrgeek  United States
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Originally Posted by sonidos View Post
Yeesh, that old NASA story has long legs on the internet. That story gets bigger and better all the time and is not entirely true.

I believe it was Fisher of Fisher pens that bankrolled the project and came about from concerns about bits of pencil lead floating in the space capsule cabin. Someone can back me up on this as I have not time to spend further on it today.

Here ya go:

snopes.com: NASA Space Pen
As far as I know, it became the Papermate Power point. The gift shop at Goddard sells "space pens".
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Old 16th February 2012, 02:02 AM   #2423
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Quote:
Originally Posted by TheShaman View Post
Measured performance suggests the 202 is a clearly superior DAC.
Which part of the measurements, if any, could explain why AMR's approach to building a D/A converter might "sound better" than Weiss' to some listeners?
I posit lack of noise modulation in the AMR vs the Weiss as the primary subjective difference. But I've listened to neither so this is just conjecture on my part.

Quote:
If we can't give a definitive answer, is it because we need more work on correlating measurements with sound quality or is it because we're measuring the wrong things?
Yes, both.

Quote:
In the latter case, do we need to reconsider the way we measure audio equipment or would it perhaps be more useful to turn our "measuring stick" to said listeners' auxiliary equipment, speakers, listening room etc.?
Well who is the 'we' ? If you're including the magazines, the more (i.e. closer) that measurements correlate with sound quality, the less there will be to write about. So I doubt they really consider such progress to be in their interests - this might be why Stereophile didn't pursue its initial foray into making measurements of noise modulation.
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Old 16th February 2012, 04:43 AM   #2424
bcarso is offline bcarso  United States
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Quote:
Originally Posted by abraxalito View Post
[snip]

Well who is the 'we' ? If you're including the magazines, the more (i.e. closer) that measurements correlate with sound quality, the less there will be to write about. So I doubt they really consider such progress to be in their interests - this might be why Stereophile didn't pursue its initial foray into making measurements of noise modulation.
I think JA would be interested in such measurements, if they were relatively easy to perform and the results sufficiently reliable. The more technical details he can write about the better, even if the subjective evaluations will always be paramount.

And considering the length of this thread and the absence of agreement, I hardly think the magazines are likely to achieve a satisfying correlation of measurements and sound quality.

But speaking of additional measurements, I hope JA can be persuaded to start measuring phono preamps taking parallel (i.e. "current") noise into account. But this is tricky, compared to merely connecting the AP2 to the preamp output and shorting the preamp's input --- despite how inaccurate this may be.
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Old 16th February 2012, 04:47 AM   #2425
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Hi,

Quote:
Originally Posted by TheShaman View Post
I was just looking at the measurements of AMR's DP-777 in the latest Stereophile and I can't help but compare them to those of the Weiss DAC-202 (published in the same magazine a couple of months ago).

Measured performance suggests the 202 is a clearly superior DAC.
Well, given that no-one has illustrated that these measurements in particular generate better sound quality if they are better, all we can conclude is that Weiss DAC actually measures better.

Quote:
Originally Posted by TheShaman View Post
Which part of the measurements, if any, could explain why AMR's approach to building a D/A converter might "sound better" than Weiss' to some listeners?
Really hard to say. But I would like to turn this around a little.

One of the main areas where the AMR processor is "worse" are noisefloor, around -132dBfs FFT noisefloor vs. -148dBfs FFT noisefloor on the J-Test signal, in other words the Weiss has 16dB Lower noisefloor. The AMR also has 120Hz PSU modulation somewhere, amounting to around -115dBfs (this can be seen in the jitter plot with zero jitter engaged - it is not actually jitter but analog noise, as is the noisefloor in the jitter plot, incidentally).

That said, if we consider peak replay SPL's and the abilities of recording microphones I would suggest that either processors noisefloor is below what is audible, to the best of our current knowledge. If it is not inaudible then the fact that Weiss's noisefloor seems heavily signal dependent, while the AMR shown no such may be a key, however I rather doubt it.

The other is distortion. The AMR shows a whopping 0.1% 2nd HD and 0.03% 3rd HD at digital full scale, dropping to 0.04% 2nd HD and 0.001% 3rd HD for -10dBFs, while the Weiss has an exemplary 0.0002% 2nd HD at 0dBfs.

However, once we relate the two sets of measurements to actual audibility of distortion at various SPL's we must conclude that distortion of either processor is unlikely to be audible and invariably will be swamped by that of the speakers used in auditioning, or even headphones.

In other words, in the areas where the performance between the two apparently differs greatly and appears to favour one product over the other, using best evidence methods we cannot support that there will be audible difference caused by the measurable differences.

So, IF there are audible differences (and in my experience, as well as that of others, there are significant differences), they must perhaps originate in areas that are not covered by those traditional measurements, as we cannot as such even support the thesis that "people like added distortion and noise" from the measured results.

Quote:
Originally Posted by TheShaman View Post
If we can't give a definitive answer, is it because we need more work on correlating measurements with sound quality or is it because we're measuring the wrong things?
I am in serious that most audio engineers have the faintest clue how the human hearing really works. When it comes to performance requirements much of what they use is purely faith based, numbers somehow concocted on a green table and never seriously referenced to reality.

This situation was made worse when the advertising people seized upon the numbers produced when measuring audio equipment as marketing tool (0.000001% Distrotion, 1,000,000 Dumping Factor, 10,000 Watt P.M.P.O. ring any bells?).

This further embedded the perception that "better measurement are a 'good thing'" with both the public at large and the engineering public, yet still no reference to reality is being made and the whole thing is no more evidence based than Scientology's Auditing as means of medical treatment.

Yet one is commonly declared to be "scientific method" and the other is a "quack cult". I would rather consider that the two have by far more in common than different (down to way in which adherents of the respective cults attempt to demonise any dissenters and the methods within which they do so...

Quote:
Originally Posted by TheShaman View Post
In the latter case, do we need to reconsider the way we measure audio equipment or would it perhaps be more useful to turn our "measuring stick" to said listeners' auxiliary eq dluipment, speakers, listening room etc.?
I think the very first step would be to actually discard the faith based foundation and to apply the scientific method. That is to use empirical evaluation of the reality, generating enough real data to attempt any determinations.

Then cross-referencing this data with related results and observations in other fields of the science of human hearing and to derive from this the information to formulate a revised, scientific and evidence based theoretical foundation for electro-acoustics that can then provide us with the necessary quantities to measure and to target.

Then an Engineer has a well defined target to design for where "good sound" is concerned.

This is eventually bound to happen, possibly sooner than later, as related fields, such as work on hearing prosthetics progresses, no matter how the Orthdox Church of so called "Audio Engineering" attempts to resist any reforms, by hook, crook and disinformation.

Ciao T
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Old 16th February 2012, 04:52 AM   #2426
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Quote:
Originally Posted by bcarso View Post
I think JA would be interested in such measurements, if they were relatively easy to perform and the results sufficiently reliable.
Well they won't be easy to perform at first - that's how things are with new techniques. Eventually they'll get built into boxes like AP2 (AP3?) and be available at the click of a mouse.

Quote:
And considering the length of this thread and the absence of agreement, I hardly think the magazines are likely to achieve a satisfying correlation of measurements and sound quality.
Decent short-term dynamic range measurements would definitely be a worthwhile step in the direction of correlating a number with factors such as 'PRaT' and perceived dynamics.
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Old 16th February 2012, 04:54 AM   #2427
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Hi,

Quote:
Originally Posted by bcarso View Post
But speaking of additional measurements, I hope JA can be persuaded to start measuring phono preamps taking parallel (i.e. "current") noise into account. But this is tricky, compared to merely connecting the AP2 to the preamp output and shorting the preamp's input --- despite how inaccurate this may be.
For MC I usually use an RCA Plug with a 10 Ohm resistor for noise measurements in addition to a short.

For MM I normally use a 10K resistor in addition to short, this will reveal any current based noise well, as real MM Cartridges tend to pick up too much environmental hum to be useful in the context.

Ciao T
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Old 16th February 2012, 05:02 AM   #2428
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Hi Dejan,

Quote:
Originally Posted by dvv View Post
Hah! You wish!
I do...

Quote:
Originally Posted by dvv View Post
And to make it just that wee bit more complicated, long gone is the rule of thumb that if you pay more, you get more. These days, the only rule is that there is no rule, you have to test just about everything yourself, and not once, but every time you get a new batch.
I do not think there was ever such a rule in audio. You always had test things yourself.

Ciao T
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Old 16th February 2012, 05:04 AM   #2429
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Hi,


Quote:
Originally Posted by dvv View Post
Anyone remember the movie "The Ghostbusters"? The scene in which Harold Ramis and Dan Aykroyd are sitting on the steps of the university they have just been fired from and are discussiong their options, when Harold says something like:

"Well, we could try the private sector",

and Dan Aykroyd quickly answers:

"Oh no, not them, they want RESULTS!"
Yes, that one was really funny and telling. And SO true.

Ciao T
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Old 16th February 2012, 07:24 AM   #2430
dvv is offline dvv  Serbia
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Originally Posted by a.wayne View Post
Ohhh those smart "Russians" they have given the world so much ... DVV where are the pics of their moon landings, i must admit , i never saw them ....
Wayne, I don't keep a tab on who did what, when and how, but I seem to remeber some writers, like Tolstoy and Dostoyevski, a series of classic music composers, and so forth. I seem to remeber a Dr Pavlov, who "invented" the Pavlov reflex, used today to the hilt by the US adevrtising, and so forth.

Ultimately, if memory serves, the first man in space was one major Yuri Gagarin, was he not?

Let's not get into that sort of thing, Wayne, not here, or we would necessarily have to bring in those people who claim and show evidence that the US astronuts never really landed on the Moon until much later than advertised. Some even poke fun at this, like in the James Bond movie "Diamonds are forever".

This would also necessarily start invoking of names, which may mean nothing to most of us, but were people whose feats in their fields are considered most important by people in those fields.

Just a small example - today's debate of whether we are globally warming or heading into a new ice age (which does not have to be taken literally) has been foreseen and a schedule worked out in 1901 by a Serbian scientist called Milutin Milanković. Fortunately, he had a tendency to write everything down, so there is a volume of his works to check this up. The best thing is that everything DID go down EXACTLY as per his calculations. And he and his work are very well known in climatology, but to us, we never herad of him.

Besides, evaluating entire NATIONS is both ridiculous and mostly untrue, simply because nations are a living body, they change, they evolve, just as we as individuals should be doing as well. I would have thought we were past things like those pesky xxx, those stinking yyy, etc.
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