The amplifier he uses has a DSP/digital crossover inside I'm pretty sure. Using the analog inputs almost certainly means another complete AD->DA conversion.
What you are comparing is your memory of real music instrument sound to that being reproduced. With frequent exposure to live acoustic instruments, anyone can learn to detect difference from the live reference.
it helps to have as neutral as possible listening room environment /speaker/listening so as to not reduce the ability to detect differences and what they are.
I also back up all that with tests and measurements, of course.
THx-RNMarsh
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If you are referring to the RC Challenge, it was the challenger's choice of venue, source, source player and all other ancillary equipment and speakers. Only the amp we brought to compare was our choice and it was inevitably a plain-jane Crown of some sort. Most of the tube guys chose TTs, most everyone else CDs. We encouraged them to choose source material they were really familiar with to help them detect differences...
Cheers,
Howie
I know the defin of accuracy and precision. I worked in a govern standards lab. making accurate and high precision measurements.
There is my subjective way (process) to learn which DUT is closest to the ref standard.
And, there is the test and measurement methods.
I use both.
I do not use LP/TT nor tube or SET because they measure poorly compared to other means. And, most sound less accurate compared to the subjective ref standard - live music.
If anyone thinks we are THERE with perfect amplifiers and systems--- just play a piano or other acoustic instrument in your living room and tell me your audio system sounds just like the 'real' thing. Not even close IMO. Though DBx shows little differences between amps et al.... it still doesnt sound very real as in Live music being played in your room.
THx-RNMarsh
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I was going to buy his best system until he didnt seem to think or Poo-Poo'ed distortion as an issue. In speakers, IMO it is a very big issue. And is one of the reasons I used new Quads amongst other reasons. Then the JBL M2 because it does everything Geddes does -- all good -- but also considered distortion. Geddes had to buy his drivers while JBL designed and made their own. maybe combining both ideas would be even better... esp regarding reducing distortion from horns as Geddes does.
THx-RNMarsh
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Re. low power and high pwr amps and speaker efficiency all matter. One could be at a distinct disadvantage over the other -- closer to noise and distortion byproducts than the other. As you noted.
Big differences dont exist until an interfacing issue arises... Like high Zo to reactive cable/load and freq response variation become great enough to detect as a difference between DUT. There are other abnormalities exposed at times. All complicating getting a fair appraisal.
But, yes the differences are now smaller than ever with thoroughly designed amplifiers. The remaining problems which make the HiFi system sound much different than live acoustic instruments is not in the amplifers so much. I talked about this before and where the problem lies.
THx-RNMarsh
This learning of real sound can also help the brain fool itself when listening to a reproduction
This doesn't, as written, make any sense. You have a way of getting to you preferred sound. That appears to be all in your subjective process.
Considering that Earl's stance on non-linear distortion is the result of two lifetimes of work (his and his partners) I think you are being a bit disingenuous here. His work on distortion mechanisms did move things forwards, just no one was interested as THD bragging rights seemed to be all that the punters cared about (which you have proved). I suspect that Toole, Olive et al would probably agree with Earl's conclusions.
You have an opinion, Earl has the results of decades of peer reviewed research. Now the customer is always right, so you chose based on your personal bias, but that doesn't mean Earl was wrong!
Well, considering the time you spend on something is not necessary correlated with success, it is not enough to trigger an act of purchase ;-)
The problem we all have, with Geeddes speakers, is they are not distributed in such a way we can listen to them next door, not even next country.
Who would like to buy a loudspeaker without listening to it ?
A second one, for me, is the quality of the drivers he choose. II do not agree (based on my 'subjective' experience ;-) it is not important, while I agree horn's shape is critical.
The last one is the solution he found to reduce the "HOM'. It looks like chemotherapy. Killing more the affected cells than the good ones ;-)
Of course,this does not detract from the high quality of his researches and the interest of his publications.
Sincerely your,
Tryphon Tournesol.
Attachments
Earl, isnt wrong. He has found and explained a serious issue (HOM) and a solution with horns.
And his work on controlled directivity is in the right direction -- but not original.
I think his finding that certain harmonics (distortion) of typical drivers is a minor issue.... side steps many forms of distortion in loudspeaker/systems. The levels of speaker distortion (harmonic/IM/transient/GD/compression) are comparable to the LP phono system. Which many people Like but isnt Accurate in many ways.
THx-RNMarsh
And his work on controlled directivity is in the right direction -- but not original.
I think his finding that certain harmonics (distortion) of typical drivers is a minor issue.... side steps many forms of distortion in loudspeaker/systems. The levels of speaker distortion (harmonic/IM/transient/GD/compression) are comparable to the LP phono system. Which many people Like but isnt Accurate in many ways.
THx-RNMarsh
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Earl Geddes did not dismiss distortions as an important factor, but objected to the usual THD figures which he considered to be mainly useless, so advocated the usage of another metric.
One aspect the JBL designers don´t cover (if it be for license reasons or efficiency or something else) is the attenuation of the inevitable HOMs by using a foam inlet.
Richard Clark´s challenge is a surprising mix, but according to the FAQ he stated that a couple of thousand people tried the challenge and that no one got more than 65% correct answers. If you calculate the probability that nobody got at least 16 correct answers in for example 2000 challenges (by random guessing) than you get p < 1x10*(-6), so it is quite unlikely that something like that happens.
Maybe "a couple of thousands" was meant in a different way, but if you do the same calculation for a couple of hundreds you still end at the this extremely low probability.
Generally it is not a good idea to use something like the ABX protocol without training for the participants under these specific conditions.
It is not a good idea to involve price money as it introduces another variable and we know from experiments (SDT) that it most likely will have an impact.
One aspect the JBL designers don´t cover (if it be for license reasons or efficiency or something else) is the attenuation of the inevitable HOMs by using a foam inlet.
Richard Clark´s challenge is a surprising mix, but according to the FAQ he stated that a couple of thousand people tried the challenge and that no one got more than 65% correct answers. If you calculate the probability that nobody got at least 16 correct answers in for example 2000 challenges (by random guessing) than you get p < 1x10*(-6), so it is quite unlikely that something like that happens.
Maybe "a couple of thousands" was meant in a different way, but if you do the same calculation for a couple of hundreds you still end at the this extremely low probability.
Generally it is not a good idea to use something like the ABX protocol without training for the participants under these specific conditions.
It is not a good idea to involve price money as it introduces another variable and we know from experiments (SDT) that it most likely will have an impact.
From what I've read Earl does not think low order gradual nonlinearities with no discontinuities (typical of speaker drivers) are very important. That is as Dick implied he did not find the THD of his drivers an issue. Please correct me if I'm wrong didn't he say that he doesn't even measure it?
WTF recommends you to criticize a lifetime of work from an obviously qualified individual? Any relevant work, beyond the DYIAudio peanut gallery contributions about your thick wallet? Can you quote a few sources that precede Dr. Geddes work on controlled directivity and explain why his contributions are not original? What you "think" is truly irrelevant by any metric. Oh, did I mention this before, "many people" is helium gas, nothing more.
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Did they use the built-in sound card in that Dell computer listed in the attached image below? Behringer doesn't appear to have a manual or any reference to that headphone amp. The headphones appear to be of intermediate quality.
I guess I'm kind of skeptical the test equipment they used might not contribute significant distortion of its own to the test, as well as possibly mask low level distortion of test signals.
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I really have no idea what they used. The thesis is here:
https://projekter.aau.dk/projekter/files/9852082/07gr1061_Thesis.pdf
https://projekter.aau.dk/projekter/files/9852082/07gr1061_Thesis.pdf
I read that and as Earl said not long ago...
LP's at their most horrifying almost never reach 15%. Mechanical systems have mild asymmetry (evens) and soft compression (odds) but no abrupt discontinuities like crossover. These things are far less audible than people think.
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