chowkwan%priam.usc.edu@usc.edu (Raymond Chowkwanyun) (04/30/91)
ADD is Spars code for a CD that was recorded in analogue, then mastered digitally. The final D means the delivery medium is also digital. The only difference between ADD and DDD then is in whether the master is analogue or digital. Is it better to make CD's from an analogue source or a digital source? In my experience the better CD's seem to be made from analogue masters. e.g. Walter's Beethoven 6th on CBS. And yet, there are recordings like Trinity Sessions by the Cowboy Junkies which I'd swear were analogue. In general then, analogue masters produce better CD's with some exceptions like the Trinity Sessions. On the other hand it can be argued that logically, if you're going to record digitally, use digital all the way. The counter-argument is that we shouldn't lock ourselves into a particular digital standard. Record in the best analogue available, then convert to whatever digitial standard is the flavor of the month. Anyway, here is a datapoint whereby you yourself can resolve this question: Jim Boyk has released a CD which allows us to compare ADD and DDD. I think it's ADD, it could be AAD. Same performance, same microphone feed. In one case to an analog tape recorder, in another to a digital RDAT. Boyk recorded his own performance of Mussorgsky's Pictures at an Exhibition. It's on his own label, Performance Recordings. PR-7 distributed by Harmonia Mundi USA. One source is Rose Records 800 955-ROSE. Both versions appear on the same physical CD. I was able to listen over a car radio as they played ADD and DDD tracks from the CD. The audience was not told which was which. The two versions were code-named Wristwatch and Fish. First they played the initial Promenade and Gnomus. Wristwatch first. I swear, after a few bars I'd identified this as DDD even without hearing Fish. The tone was thin and edgy. When Fish came on there were more harmonic overtones. Ahh, it just sounded more like a piano. Then they played the Ballet of the Chicks in Their Eggshells. This time Fish came first, followed by Wristwatch. This was a much harder call. CD's biggest weakness is treble so that in a piece which emphasizes treble like Ballet, any differences in the underlying master are obscured by CD's veiling effect. I thought Wristwatch sounded marginally better although both were pretty thin and edgy. Turned out Wristwatch was DDD. Another listener pointed out that Wristwatch was a bad code-name because people associate wristwatches with digitial technology. Maybe Fowl? The idea is to use code-names which are totally neutral. Another question: would you say this was a double-blind or a single-blind test? Technically, it's single-blind since the radio people knew which was which. But since it was a broadcast and I couldn't see their faces for visual clues, I'd say it was in effect a double-blind test. Oh yes, listeners called in to say which one they preferred. Much to the annoyance of Peter Sutheim (host of Infidelity 12:00 pm Sundays KPFK in LA), people kept trying to identify whether the master was digital or analogue instead of just saying which they liked better. The final tally 7.5 for Wristwatch, 5.5 for Fish. i.e. most people liked the DDD version better. Another listener complained about the wow and flutter on this broadcast which the radio guys confirmed. This appeared even on the DDD version. Boyk assured us he had heard the same physical CD on another player and that there was no wow or flutter. It was the radio station's el cheapo player that was at fault. This is public radio we're talking about. So OK, maybe the results would have been different if they'd used a really high-grade CD system, nevertheless it was the same physical CD played on the same player. Anyway, try it for yourself in your own high-grade player. Minor anecdote: Boyk said that the ADD version overloaded a $50K system but played OK on a $2K system. This was someone he'd lent the CD to. Moral: high-end audio is being designed with the lesser dynamics of CD in mind. Finally, for those still into vinyl there is an LP version. -- ray
jfw@neuro.duke.edu (John F. Whitehead) (05/03/91)
In article <11579@uwm.edu> chowkwan%priam.usc.edu@usc.edu (Raymond Chowkwanyun) writes, in part: >Jim Boyk has released a CD which allows us to compare ADD and DDD. >Boyk recorded his own performance of Mussorgsky's Pictures at an Exhibition. >I was able to listen over a car radio as they played ADD and DDD tracks >from the CD. The audience was not told which was which. >Oh yes, listeners called in to say which one they preferred. The final tally >7.5 for Wristwatch, 5.5 for Fish. i.e. most people liked the DDD version >better. I would take this "test" with a grain of salt, even if 7.5 were to be considered statistically significant vs. 5.5. How can you expect to test something so subtle when you broadcast it? A radio signal is compressed, and doesn't have any signal over 15KHz or much below 50Hz! John Whitehead Internet: jfw@neuro.duke.edu Department of Neurobiology jfw@well.sf.ca.us Duke University Medical Center Bitnet: white002@dukemc Durham, North Carolina