Sin diferecias palpables entre SACD y DVD-A pero ni entre esos formatos contra el CD

¿Son de hecho los CD lo suficientemente buenos como para no necesitar de nuevos formatos?




The Emperor's New Sampling Rate
ARE CDS ACTUALLY GOOD ENOUGH?
Artículo de Paul D. Lehrman

http://www.mixonline.com/news/profiles/emperors-new-sampling-rate/365968

Un estudio hace años donde ni el DVD-A ni SACD se hacen notar mucho el uno del otro, y par colmo de los HD Audio ese estudio tampoco encontró marcada ventaja, si es que alguna entre DVD-A/SACD y el viejo y cumplidor CD. Y me atrevo a decir que aplica para muchos, la mayoría de casos del re empacado y re etiquetado Audio HD ahora vendido en linea y no en discos.


The number of times out of 554 that the listeners correctly identified which system was which was 276, or 49.82 percent — exactly the same thing that would have happened if they had based their responses on flipping a coin. Audiophiles and working engineers did slightly better, or 52.7-percent correct, while those who could hear above 15 kHz actually did worse, or 45.3 percent. Women, who were involved in less than 10 percent of the trials, did relatively poorly, getting just 37.5-percent right.

 ...information about the signal chains and the source material within a couple of weeks of the article's publication on the Website of the Boston Audio Society, a venerable 37-year-old, independent non-profit organization, in which both authors have long been active. The equipment list included amplifiers from high-end manufacturers like Adcom, Carver, Sim Audio and Stage Accompany, and speakers from Snell and Bag End, as well as the oft-worshipped Quad ESL-989 electrostatics, which are supposed to have usable response up to 23 kHz — which is, of course, above the Nyquist frequency of the HHB recorder's converters. The subjects listened to discs that covered a wide range of material and included classical instrumental, choral, jazz, rock and pop, from audiophile labels like Mobile Fidelity, Telarc and Chesky.

Muy bien, siempre hay que dejar lugar para seguir evaluando y descubriendo "Does this mean that someone else couldn't do a similar experiment and end up with different results? Not at all." 

But something is causing people to say they are hearing differences. If a double-blind test can't confirm those differences, then what's going on? For one possible reason, let's go back to Moorer's paper that I quoted earlier (called “New Audio Formats: A Time of Change and a Time of Opportunity,” which can be found on his Website,www.jamminpower.com). Later in the paper, Moorer noted that humans can distinguish time delays — when they involve the difference between their two ears — of 15 microseconds or less. Do the math, and you can see that while the sampling interval at 48 kHz is longer than 15 µs, the sampling interval at 96 kHz is shorter. Therefore, he says, we prefer higher sampling rates because “probably [my emphasis] some kind of time-domain resolution between the left- and right-ear signals is more accurately preserved at 96 kHz.” It's an interesting starting point for a discussion, but to my knowledge it's never gotten past that point — as a theory, it has never been expanded upon or tested. And judging from the results of Meyer and Moran's experiment, it doesn't seem to be a factor. 


Y entre todo esto del Audio HD hasta surge una conjetura plausible respecto al por que se escuchan cambios con cables o algunos accesorios o equipos high end, suena como sujeta con alfileres deteniéndose apenas pero no se está tampoco en posibilidades de   desecharla  ¿Es todo un filtro de peine?:

Ethan Winer — a musician, engineer, studio owner, manufacturer and iconoclast who's been in the recording business for some 40 years: moving one's head or listening position as little as four inches can result in huge changes in the frequency-response curves one is hearing. What could be a 10dB dip in one spot at one frequency could be a 6dB boost a couple of inches away. These wide variations are caused primarily by comb-filtering effects from the speakers and from the various reflections bouncing around the room, which are present no matter how well the room is acoustically treated. Winer blames this phenomenon for most of the unquantifiable differences people report hearing when they are testing high-end gear.

He writes, “I am convinced that comb filtering is at the root of people reporting a change in the sound of cables and electronics, even when no significant change is likely. If someone listens to their system using one pair of cables, then gets up and switches cables and sits down again, the frequency response heard is sure to be very different because it's impossible to sit down again in exactly the same place. So the sound really did change, but probably not because the cables sound different!”.

Arriesgada y suena más imposible que decir que sí hay cambios por que tampoco varía tanto el lugar de escucha al volverse a sentar uno.