morris@utah-cs.UUCP (Richard Morris) (01/28/84)
I am amazed at the people who say that they can hear great problems with high quality digital audio, especially considering the kinds and types of distortion that either a good analog recorder, or the cutting stylus and associated drive equiment in the case of direct to disk, introduces; which, these "golden ears" have more or less given their seal of approval to, by saying they sound so much better than their digital counterparts. I am of the opinion that those most offended by digital audio are those who have a financial interest in analog music like some of the direct to disk companies, or someone with a small fortune tied up in esoteric audio equipment; or merely someone with a distorted view of the real world. I wonder if anyone has done a double blind test, as described below, to determine if those people with "golden ears" who claim to hear such atrocities with digital audio really hear such things, or just have an overly active imagination. I propose taking a high quality analog recording either on analog tape or audiophile disc, and recording it with a HIGH QUALITY digital recording system. Then play the two back seperately and in an A/B comparison situation. Since the record noise and/or the tape hiss and other analog recording troubles present in the analog original will also be present in the digital recording, these won't be available as clues for the "golden ears" to distinguish between the two recordings. I strongly suspect that under such conditions ANYONE would be hard pressed to correctly identify which recording was which, by the supposed problems digital music critics claim to hear; especially if the digital test system uses digital filtering and gradual slope low pass filters. If one looks at the signal processing theory of the analog-to-digital-to-analog conversion process, there is NO information loss if the rules are followed, just some noise introduced as a result of the quantization. Until the above experiment is tried several times under controlled conditions with conclusive results, I will continue to be unconvinced at the claims of the opponents of digital audio. Comments anyone? !harpo!utah-cs!morris
pmr@drufl.UUCP (Rastocny) (01/30/84)
Here we go again. Agreed that to prevent people from identifying the analog recording you must also record the tape hiss. Nothing wrong with the approach. But you probably couldn't pay "golden ears" types to sit through a double-blind test for more than two switchings. The second or third generation digital playback systems mentioned are better sounding than their predecessors. But there is still, although granted not as much as there used to be, a significant difference in the way instruments with higher-order harmonics sound, not to mention the lack of hall ambience. If you picked programme material that excluded the CD's shortcomings, most people probably couldn't tell the difference. But remember that other people have already complained about these differences (Re: the Windham Hill CD vs. analog report). As a side note, I also believe that it is NOT the digital recorder that is to blame, although the Soundstream and the new 3M recorders appear to sound better than some others. I feel that improvements to the chain involved in making CD software and also the error-detection schemes used in CD players could use some help. (I can feel the flames already.) It is frustrating to discuss things like this with people who can't hear what you're talking about. Yours for higher fidelity, Phil Rastocny AT&T-ISL ..!drufl!pmr
rentsch@unc.UUCP (Tim Rentsch) (02/04/84)
Wonderful proposal. I'm all in favor of it. Some problems remain:
(1) funding
(2) equipment
(3) playback fidelity
Point three is especially ticklish. What's the point of doing the test if
it's going to be done on, e.g., Bose speakers? Getting accurate reproduction
*after* the material being tested is crucial -- these days when I hear of
an experiment which "proves" some claim about audio, the first question I ask
On what equipment was the test done? The minimum here is amplifier and
speakers. If that information isn't included, the test is worthless.
Just by the way, if I hear again that CD's have "no information loss" I
think I'll be sick. Some things to think about:
(1) The nyquist limit applies only if the samples are *infinite* precision.
Last time I checked 16 bits was far short of infinity.
(2) The implicit claim is that there is no information content above
20kHz. Even if I grant that people can't hear sine waves above
20kHz (which I don't -- but that's another story) that does *not*
mean that there is no information content above 20kHz.
Tim Rentschjab@uokvax.UUCP (02/05/84)
#R:utah-cs:-242700:uokvax:1000003:000:660 uokvax!jab Feb 3 18:03:00 1984 There exists an album that is recorded three times: in "normal" analog, as a "digital" master, and as a "high-speed analog" master. I saw it today in Rose Records in downtown Chicago, and although I forget the selection (a Bruckner symphony?), I remember one important detail: THEY DON'T TELL YOU WHICH METHOD WAS USED FOR ANY SIDE. The recording methods are labeled "Method 1," "Method 2," and "Method 3." You can write to the manufacturers and find out which methods correspond to which side. If I had any faith in my turntable/stylus (time to either get a new one or get a CD player, tired of ruining records) I would grab it. Jeff Bowles Lisle, IL
rentsch@unc.UUCP (Tim Rentsch) (02/06/84)
"Probably you couldn't pay 'golden ear' types to sit through a double blind test"? Is that so? Well, I don't claim to have golden ears, but I'm available for any serious test (on good equipment, I mean). (For those who insist on "getting their money's worth", I will be happy to accept payment. :-) ) Tim
pmr@drufl.UUCP (Rastocny) (02/07/84)
Tom, Glad to see others expressing what they hear. This is discussion is getting interresting. Phil Rastocny
rmd@hpcnoa.UUCP (02/19/84)
There was an article in Audio magazine a couple of months ago reporting the results of Dick Burwen's experiments with digital recording. This is close to what you're asking for, but just one man's opinion and the tests were certainly not 'double blind' or even very well controlled. Rick Dow inhp4!hpfcla!rmd