From: utzoo!decvax!harpo!utah-cs!utah-gr!thomas Newsgroups: net.audio,net.physics Title: Re: Digital Vs. The Audiophile. Article-I.D.: utah-gr.666 Posted: Fri Dec 17 09:50:48 1982 Received: Wed Jan 5 20:18:34 1983 References: rocheste.326 At the risk of being flamed off the net (watch out for the Geisthounds!), I will add my two cents to this debate. 1. How many of you can hear 20kHz anyway? Can you hear the whine of a TV set (15.75kHz)? If so, can you hear the ultrasonic burglar alarms in some retail stores (K-Mart has them around here) (about 18kHz)? If you answer no to either of these questions, then you have nothing to worry about when it comes to 20kHz signals (whether sine or square). 2. You certainly can't record a 20kHz square wave on most analog recording media, either. Most serious listeners have cassette decks these days. How many cassette tapes have a frequency response above 20kHz? How can you say "digital is inferior because it won't reproduce a 20kHz square wave" when your current medium won't either? If somebody can show that the human ear can distinguish between a sine wave and a square wave at the upper limit of hearing, then this is a motivation to improve things. Note that feeding a sine wave and a square wave into a speaker and listening for the difference doesn't count as a proper comparison (as somebody pointed out), because of non-linearities in the reproduction system, a square wave can actually cause some lower frequencies to be generated by the speaker. A valid comparison would involve generating sine and square pressure waves in the air. 3. Even listening comparisons must be done carefully. I used to work for a small digital audio firm, and we got one of a competitor's recorders in once (a large recording firm had a large backlog because editing using this competitor's system was very difficult, and they asked for help in getting a couple recordings edited). The converters in this recorder were so badly adjusted that they were introducing about 20dB worth of noise into the recording and reproduction! Although the theoretical S/N ratio was 96dB, the actual measured S/N was 70dB. Needless to say, this made music played on this system not sound as good as it could have. It would be a shame if sloppy manufacturing practices ruined the potential of digital recording. 4. For those of you who claim that listening is the real test, I have done a lot of listening to REAL digital recordings (not the record pressings, but the actual bits themselves). They have been, in general, the best reproductions of music I have ever heard. Instruments such as trumpets and drums, which suffer badly in most traditional recording media, sound just like trumpets and drums. The imaging is fantastic (arguing against those who claim that digital recording will necessarily introduce huge phase shifts). When I closed my eyes, I could imagine that I was sitting in the ideal seat in an otherwise empty concert hall, listening to a flawless performance (since mistakes can be edited out). It was the best listening experience I have ever had. I for one, can't wait for home digital (but when I get mine, I'm going to take it to my friendly local digital music company and get those D/A converters adjusted, that's for sure). Digitally yours, Spencer