If you can hear it, it must be measurable

[AngelRa]

"Everything" is a lot more than just a complicated test formula for good sound. Actually, BOSE claim the same since the 70's. They call it "Psycho-acoustics", nothing new, all marketing.

This forum is about "If you can hear it, it must be measurable" in other words, StarTrek stuff, know everything the ear-brain could process and have measurements for it! From an engineering point of view it is laughable.

[whoaru99]

Originally Posted by AngelRa

From an engineering point of view it is laughable.

Really?

From an engineering standpoint, and bearing in mind this isn't about preference or what any given person thinks sounds best, what can I hear that cannot be measured?

[RickB]

As Einstein said:

"As far as the propositions of mathematics refer to reality they are not certain, and so far as they are certain, they do not refer to reality."

"Science can only ascertain what is, but not what should be, and outside of its domain value judgments of all kinds remain necessary."

"Information is not knowledge."

"The only source of knowledge is experience."

And finally:

"Everything that can be counted does not necessarily count; everything that counts cannot necessarily be counted."


Therefore, to me, this means that a much greater mind than any of us that inhabit this board understood what subjectivists have said about audio qualities....these same subjectivists' dissatisfaction with many of the audio qualities of the gear produced in the early days of solid scrape that met all kinds of impressive measurments, by the way, has led to better engineering methods in the manufacturing of audio gear and given us much, much better gear, especially once you forgo the mass market, mass produced dreck, which by the way, has also improved due to improved construction conventions adopted since the subjectivists first began hearing how bad 99% of the gear produced then really sounded...like getting rid of ceramic or tantalum capacitors in the signal path for only a tiny example...

Believe me, I do understand the need for measurements and the validity of those wanting to find the holy grail of the "Audio Unified Field Theory"...but, I feel that by time audio reproduction will have reached such a stage that:

A: The toll of crappy MP3 encoded music has taken it's toll and there aren't any listeners that even give a damn about accurate or natural sounding music...

B.: The state of the art has advanced to such a state that even the most musically accurate and free from distortion systems are available from places like Big Lots or Sears

C: December 21, 2012 really is the end....no mas music anywhere anyhow...

.

[AngelRa]

2012 YES!, I am going to see it, it will be fun, I love the JBL large arrays with 3 x 18" subwoofers of the local multiplex.

[Spikedart]

Originally Posted by whoaru99

Yes and no, IMO.

It may mean that, or it could just as easily mean that you or I (speaking generically) don't know how, but those skilled and knowledgeable in acoustical sciences could do it today, with what we have now.

Harman Industries is doing this sort of thing with speakers in the present. They have identified several key measurements of speakers that seem to correlate very closely with listener preference. Now, does this mean that something new won't be discovered tomorrow? No, of course not, but that applies to anything. But, IMO, we're pretty adept in the here and now and to me that means you do with what's available, not just say, "Oh, we don't know everything, so we really can't talk about anything with any degree of certainty."

this whole thread has come down to conjecture. so sad.

[sheltie dave]

A tech friend in town helped invent and manufacture the leading cochlear implant at the Central Institute for the Deaf here in St. Louis. CID hat two aneochic chambers to test and conduct research on sound, auditory science, and the physics of hearing.

Measurement and listening in music creation, recording, and playback are so inextricably interwoven that the lack of balance, or the absence of either, leads to an abrupt loss of quality. There is a Six Sigma process to music, with those who cleave closely to the principles to be closer to being successful in their efforts.

We measure everything in the process. The materials used to make the instruments, the diameters, lengths, thicknesses, stresses, torques, tensions, are all designed to be just so. The floors, walls, ceilings, dimensions, angles, and playing positions are just so. The mics are selected, positioned, primped, wind and spit screened just so, height and breadth adjusted. The RTRs are calibrated, the electrical power filtered, the time of day selected to minimize extraneous noise(or band alertness) again just so.

There are not too many examples of great stereo gear that have not gone through the crucible of extensive measuring. Unless you like listening to rambunctious hootenanys, the amount of measurements that go into what has been recorded and is now playing at your house is immense. You don't need to delve deeply, or even at all, into what has transpired, but it should be apparent that good measurement as an art/science fully supports, and is equal to, good listening.

[Spikedart]

thanks Dave. It's good to see that research is going on that benefits everyone with ears. Indeed more important that many of the things we tend to discuss here.

[Aydin]

Originally Posted by sheltie dave

There are not too many examples of great stereo gear that have not gone through the crucible of extensive measuring.

I was going to have a massive ramble here, but I'm trimming it down to just a large ramble instead...

I think we need to look a bit further than the measurements we have, since they're just being abused in studios by people who don't understand what the outputs mean (ie. think the spectrum analyser should show equal power across the entire spectrum at all times) and abused by manufacturers who want to pull the wool over our eyes with meaningless data (although there are some exceptions here).

By way of an example, say an amplifier is rated 35W into 8 Ohms over 5Hz-25kHz with no more than 0.1% THD...

35W is assuming an 8 Ohm resistive load, which a speaker isn't - at some frequencies, the amplifier may be supplying considerably less (or more) power, which in turn may affect the distortion performance and usable frequency response.
If the speaker can reproduce frequencies outside the rated response of the amplifier, then there is no data at all to allow even an educated guess as to what might happen. There could, for instance, be a sudden peak of noise at high frequencies which was overlooked during the design owing to the designers already "knowing" the response of the amp. Supertweeters and older MOSFET amps come to mind, here...
Finally, the THD measurement. This is one of my pet hates. Trying to explain to someone why an amplifier with 10% even-order harmonic distortion can sound nicer than one with 1% odd-order is very difficult. Manufacturers would rather have it that way since adding masses of negative feedback is an easy way to increase frequency response and decrease the total distortion, so making the amp look "better" on paper. Sadly for our ears, NFB and many other distortion-reducing technologies are better at lower frequencies with even-order harmonics, and so tend to cancel the "nice" even-order distortion and leave some of the higher odd-order instead, or even increase it in some circuits. Graphs or tables of the relative levels of each harmonic would be an excellent way to compare the actual THD performance of two pieces of equipment, but this is virtually unheard of...

To sum all that up, I'd say we need a better picture of what equipment can do by using *all* the currently available testing methods and showing *all* the results from these tests. This means the manufacturers can't hide behind "useful" figures, we get a better picture of what we're buying is actually capable of and we don't need to introduce any fancy new tests ... Yet!
The problem here is then twofold: Cost (to manufacturers, and thus to us) and ease of understanding (providing that much data in an easy-to-understand manner for "Joe Public" is virtually impossible).

[Bigerik]

Originally Posted by Aydin

I was going to have a massive ramble here, but I'm trimming it down to just a large ramble instead...

I think we need to look a bit further than the measurements we have, since they're just being abused in studios by people who don't understand what the outputs mean (ie. think the spectrum analyser should show equal power across the entire spectrum at all times) and abused by manufacturers who want to pull the wool over our eyes with meaningless data (although there are some exceptions here).

By way of an example, say an amplifier is rated 35W into 8 Ohms over 5Hz-25kHz with no more than 0.1% THD...

35W is assuming an 8 Ohm resistive load, which a speaker isn't - at some frequencies, the amplifier may be supplying considerably less (or more) power, which in turn may affect the distortion performance and usable frequency response.
If the speaker can reproduce frequencies outside the rated response of the amplifier, then there is no data at all to allow even an educated guess as to what might happen. There could, for instance, be a sudden peak of noise at high frequencies which was overlooked during the design owing to the designers already "knowing" the response of the amp. Supertweeters and older MOSFET amps come to mind, here...
Finally, the THD measurement. This is one of my pet hates. Trying to explain to someone why an amplifier with 10% even-order harmonic distortion can sound nicer than one with 1% odd-order is very difficult. Manufacturers would rather have it that way since adding masses of negative feedback is an easy way to increase frequency response and decrease the total distortion, so making the amp look "better" on paper. Sadly for our ears, NFB and many other distortion-reducing technologies are better at lower frequencies with even-order harmonics, and so tend to cancel the "nice" even-order distortion and leave some of the higher odd-order instead, or even increase it in some circuits. Graphs or tables of the relative levels of each harmonic would be an excellent way to compare the actual THD performance of two pieces of equipment, but this is virtually unheard of...

To sum all that up, I'd say we need a better picture of what equipment can do by using *all* the currently available testing methods and showing *all* the results from these tests. This means the manufacturers can't hide behind "useful" figures, we get a better picture of what we're buying is actually capable of and we don't need to introduce any fancy new tests ... Yet!
The problem here is then twofold: Cost (to manufacturers, and thus to us) and ease of understanding (providing that much data in an easy-to-understand manner for "Joe Public" is virtually impossible).

Nice, thought provoking, post.
Thanks