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Compilation of blind test reports
krabapple
post Jan 23 2012, 05:14
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I was wowed when I came across this -- someone went to a lot of trouble to compile most of the print and online audio equipment DBTs since the 90's

first post here:
http://www.head-fi.org/t/486598/testing-au...laims-and-myths

btw pretty sure he's wrong about Meyer & Moran only using CD-sourced SACDs, but I'll correct him on that ;



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mzil
post Jan 23 2012, 07:14
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Moran and Meyer said they used "mostly" this (and each test subject got to pick whatever they felt most comfortable with, if I understand correctly):
QUOTE
Patricia Barber Nightclub (Mobile Fidelity UDSACD 2004)
Chesky: Various -- An Introduction to SACD (SACD204)
Chesky: Various -- Super Audio Collection & Professional Test Disc (CHDVD 171)
Stephen Hartke: Tituli/Cathedral in the Thrashing Rain; Hilliard Ensemble/Crockett (ECM New Series 1861, cat. no. 476 1155, SACD)
Bach Concertos: Perahia et al; Sony SACD
Mozart Piano Concertos: Perahia, Sony SACD
Kimber Kable: Purity, an Inspirational Collection SACD T Minus 5 Vocal Band, no cat. #
Tony Overwater: Op SACD (Turtle Records TRSA 0008)
McCoy Tyner Illuminati SACD (Telarc 63599)
Pink Floyd, Dark Side of the Moon SACD (Capitol/EMI 82136)
Steely Dan, Gaucho, Geffen SACD
Alan Parsons, I, Robot DVD-A (Chesky CHDD 2003)
BSO, Saint-Saens, Organ Symphony SACD (RCA 82876-61387-2 RE1)
Carlos Heredia, Gypsy Flamenco SACD (Chesky SACD266)
Shakespeare in Song, Phoenix Bach Choir, Bruffy, SACD (Chandos CHSA 5031)
Livingston Taylor, Ink SACD (Chesky SACD253)
The Persuasions, The Persuasions Sing the Beatles, SACD (Chesky SACD244)
Steely Dan, Two Against Nature, DVD-A (24,96) Giant Records 9 24719-9
McCoy Tyner with Stanley Clark and Al Foster, Telarc SACD 3488


Source: Boston Audio Society

But with the exception of Steely Dan, Two Against Nature (which mentions "24,96"), how exactly would one go about finding this out? Even if one owned all these discs I doubt a single one reads on its liner notes: "Oh, by the way, this is from a CD resolution master." (even if that might be true in some instances, I have no idea).
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Arnold B. Kruege...
post Feb 15 2012, 14:56
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It is now known that many SACD releases were actually transcribed from digital and analog sources that are sorely lacking in significant content > 22 or 24 KHz. Some came from digital masters sampled at 44 or 48 Khz, and some came from analog tape recordings that had a natural steep cut offs in the 22-24 KHz range. Many were also made with microphones with steep cutoffs as low as 12 KHz.

Exactly which of the above fit into that category is unknown to me, but sources indicate that on the average up to half of them can reasonably be expected to suffer from these problems.

Therefore the Meyer and Moran tests may not have been what some interpreted them to be. Their tests may have been contaminated with with large amounts of program material that did not have significant content > 22 KHz. Therefore, these recordings cannot be reasonably expected to sound different in their tests which in essence involved the audibility of removal of all program material > 22 KHz. If the > 22 KHz program material was not there to remove, then removing it must have no effect!

This post has been edited by db1989: Feb 15 2012, 23:07
Reason for edit: deleting pointless full quote of above post
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Porcus
post Feb 15 2012, 16:55
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QUOTE (Arnold B. Krueger @ Feb 15 2012, 14:56) *
analog tape recordings that had a natural steep cut offs in the 22-24 KHz range.


A limitation in the recording (e.g. write heads etc.), or in the tape medium itself? (Like: could we be listening to digitally faithfully reproduced tape hiss caused by master tape deteroriation, which no-one cared about in old days when the read heads could not pick it up anyway?)


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Arnold B. Kruege...
post Feb 19 2012, 13:35
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QUOTE (Porcus @ Feb 15 2012, 10:55) *
QUOTE (Arnold B. Krueger @ Feb 15 2012, 14:56) *
analog tape recordings that had a natural steep cut offs in the 22-24 KHz range.


A limitation in the recording (e.g. write heads etc.), or in the tape medium itself?


That depends, but it is more likely that it is the tape heads that are doing more to set the observed FR limits than anything else. There are steep cut offs during playback that commence when the wavelength of the signal on the tape is the same size or smaller than the gap of the tape head. Tape head gap sizes are usually constrained by the technology used to create them, and also the other problems that arise when they are very small.

QUOTE
(Like: could we be listening to digitally faithfully reproduced tape hiss caused by master tape deteroriation, which no-one cared about in old days when the read heads could not pick it up anyway?)


Back in the day we were pretty happy when our tape recorders were reasonably flat up to say 16 KHz, particularly at higher recorded levels. There are other problems, such as the fact that the dynamic range of audio tape and the recorder decreases with increasing frequency.

Most professionally-made recordings made in the late 1970s and early 80s were not afflicted with clearly audible tape hiss. The record/playback equipment and media were good enough to keep noise levels reasonably low. We also had various noise reduction strategies such as Dolby A that were very effective at reducing audible tape hiss so that it wasn't a problem.

We have better tape heads for playback today than we had back in the day. However, anybody doing transcriptions of old tapes might be conflicted by the polar ideas of playing the tape back as it was intended to be played back when it was recorded, versus playing the tape from the archives back with the best technology that is available today.
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