August 17, 1974
DORREN TELLS OF PIONEER ROLE IN 4-CHANNEL
By CLAUDE HALL
EDITOR'S NOTE: Lou Dorren is research director of Quadracast Systems Inc., a firm that is located in an obscure building in San Mateo outside San Francisco. The building bears no sign. Inside, you'd find tons of electrical equipment, some of it jury-wired like a nightmare because, after all, it's 99 percent experimental and the only of its kind. All of the place is immaculately clean. Several Japanese engineers
work with Lou. He, now 25, is ostensible boss. He works hard, moves fast, carries a computer in his shirt pocket that he can program to play blackjack against you at Las Vegas odds or figure out the most complex of electronical calculations. He is the inventor of the discrete broadcasting system submitted to the Federal Communications Commission a couple of years ago that set off the quad race in both records and radio in the U.S. He has also invented countless other items and devices and these range from a cleaning compound for CD-4 discrete records to a new revolutionary integrated chip discrete CD-4 quad demodulator. The interview was conducted by Claude Hall, radio- TV editor, Billboard Magazine.
H: For the ordinary listener, what's the advantage of quad over stereo?
D: For the first time, the listener is getting a chance to hear, from his electronic system, his home hi-fi unit, his "appliance," if you will, what he hears in real life. What you're actually hearing right now around the room is that guy in the blue jacket behind you talking: you're not necessarily listening to him, but if you stopped listening to me, you could hear him stronger; you could hear what he's saying. Discern that it's coming from the back of you. Likewise, you can discern around you--even though you only have two ears--where sounds are coming from. This is what quad is all about. Specifically, electronic quad does not change what is put into it-I'm talking about discrete, obviously-the fact is, you can reproduce exactly what you're hearing now, in normal circumstance, with quad.
H: One of the things that some people joke about . . . especially those who don't know one damned thing about quad . .is that if. . .
D:...if man was meant to have quad, why doesn't he have four ears? The fact of the matter, Claude, is that man probably really does have four ears. In the way that the human ear is made. If you cut off the ear and just have a hole there on each side, you lose most directionality. These things here that they call ears, which are actually just the outside shells, actually help you in hearing because they pick up source sounds and reflections and give you that ability to discern direction.
H: Do you think that quad is more pleasant to listen to than stereo? What's the advantage?
D: Not only is it more pleasant, but it's more exciting! It's more realistic. Besides the fact . .. well, okay, there are isolated instances where people will point out classical music as an example . . . you've been there, Claude...they'll use classical music as the ideal quad situation. It's not. Sure, it's a nice demonstrational tool, classical musical. But it's not the only tool that's there. Things can be made, via the recording studio techniques that have been used for years, into a completely three-dimensional representation of what the recording artist really was saying to the listener. You can't do this with stereo. Plus, of course, to really get the best stereo effects, you have to sit in the middle of the speakers. And a little bit back. In order to get that left-to-right type of thing. But with discrete quadraphonic, you don't have to do that. . . you don't have to be in a preferred position . . . you can be anywhere in the sound field.
H: Why do you use the term quadraphonic, when that's a combination of Latin and Greek?
D: Only because the industry has accepted it. In actual fact, it should either be quadrasonic or tetraphonic. I agree with you, I'm kind of upset about it, but, however, what can you do about it. To pun, when in Rome, do as the Romans do even if it's quadraphonic.
H: When did you, personally, hear quadrasonic 4-channel sound?
D: Hah! You're hedging, Claude. But, well, I first heard 4-channel sound in 1969. As far as the type of quad that we're talking about.
H: What, un, were you then?
D: At that time, I was an electronics design engineer. However, let me back up a little. I had used 4-channels as a mix-down point when I was in the recording business. When I was a recording engineer, I did use at certain times, back in 1967 and 1968, as a mix-down point from 8 and 16-tracks, 4-channels. We would mix down to that to see what it sounded like before we went on down to stereo, otherwise known as 2-channels.
H: What studio did you work at?
D: I did some work for the old Fantasy Records that turned out to be Trident Productions in San Francisco. I also did some work for Coast Recorders in San Francisco; in fact, I aprenticed there under one of the better recording engineers-Mel Tanner. Basically, what I was doing there, well, it was not a paid deal, but I was working there after school. . I was going in and learning the recording business. I was really excited about it.
H: As a high school student?
D: Yeah. It was good experience. I did that, I think, for about four years.
H: But when you heard the first 4-channel broadcast by two stations--the fountainhead of everything that happened later, more or less-you were a college student?
D: That is correct. At that time, I was going to California State University in San Francisco.
H: What's the whole story behind everything that happened?
D: I'd heard the two-station broadcasts. And one evening I was reading a book about how Leonard Feldman and Bill Hal-stead had told the industry how they felt that a way to transmit quad would be to have regular stereo with two subcarriers with eight kiloherz response for ambivance only of classical music. Again, that was another idea where classical music was the only thing they were talking about. At that point, for some reason, it came to me. That was not the way to do it. I stayed up the whole night and pulled out a lot of stuff that I had in my own little lab at home and built a prototype of what is now the system up before the FCC. It was crude, but it proved to me that my ideas worked. From then, I filed a patent application ...we formed Quadracast Systems Inc. with another gentleman from San Mateo-Tom Lott--and the rest is pretty much history.
H: Unwritten, as yet, history. The story has been that you called Jim Gabbert, owner of K101-FM in San Francisco.
D: That's correct. After I came up with the idea for quad broadcasting on a single station, I knew that somebody had to be interested in it. I also knew Jim's reputation in regards to stereo. He was really the father of stereo from the standpoint of making it work in the broadcasting industry. He didn't invent it, but he was certainly the one who made people accept it as a viable medium for FM. So, I figured what the heck, I'll call him. Tell him what I've got. After all, he'd been doing some 4-channel broadcasting with his station in teamwork with another local station. So, I called him. The initial impression I got over the phone was: Jesus, here's another one of those crack-pot kids, you know? But I managed to talk him into a meeting and went to the station to talk to him. About 20 minutes after I started talking, all of a sudden his face lit up. He asked me when he could come to the lab and hear it. He came down about two or three days later and listened to it. Then he asked if he could have it ready for the National Association of Broadcasters convention. We took to the convention. That was the 1970 meeting in Chicago. Jim Gabbert said he'd talked to a lot of people who didn't think it possible to put four signals in the bandwidth present on FM. I knew stereo, but I really didn't know the rules and regulations of the Federal Communications Commission. So, I looked into the rules. I came to the conclusion that there was no reason why it wouldn't fit. Because the FCC, having a reasonable enough hindsight, allocated enough space for quad on the FM band.
H: Some German engineers and broadcasters that I have been seeing claim there isn't enough bandwidth for quad.
D: Only because quad wasn't invented in Germany. We did a test broadcast for 10 days in Berlin last year. The government there didn't tell us, but were monitoring the broadcasts.
About the sixth day, a man came over and talked to me, stating that the signal looked like a stereo signal on his modulation monitors. He said: It doesn't take up any more band-width. I said that was what I'd been telling him all along.
H: At the first meeting with Gabbert, there was you, Tom Lott, and. ...
D: And Mike Lincoln, K101-FM station manager, Gabbert was skeptical at first. But when he came to the lab, he spent three hours and when he left, he was convinced that discrete broadcasting would work. It became at that point just some work getting our breadboard item prettied up in some boxes for the NAB meeting. At the unit you saw and heard in Chicago-which was the first time I was introduced to you-was that unit.
H: After the FCC approved the experimental broadcasts at
K101-FM, did you help build the transmitter that was used?
D: Well, we built the generator, but we didn't have to do much to Gabbert's transmitter. It's so broad, that we just plugged in and it worked. In fact, the most trouble we had was in getting the audio signals from the studio to the transmitter.
We spent more time on that, than anything else. One of the microwaves had a bad tube. We had four microwaves . .. one for each channel. And we tore our hair out for three days trying to fix that damned thing.
H: Were the very first tests successful?
D: In my own opinion-and I'm doing this as objectively as I can--the tests proved without a doubt that the Dorren system was not only feasible, but was a viable method of putting four channels of information on radio.
H: One criticism that has been voiced about 4-channel broadcasting is that you double the so-called picket fence effect for automobiles . . . the blip-blip you hear on a stereo car radio as you drive.
D: That's not true. It's true if you put an SCA in there, using a sideband for Muzak or something . .. but untrue about quad.
H: What's your opinion about the SCA?
D: That's a loaded question, Claude.
H: Right. Supposedly broadcast waves are in the public domain, but here's a facet of radio being used not for the public interest. When have you heard news and community service programs on Muzak?
D: I have no opinion, politically, on the use of the SCA.
Technically, I think 67 Kh, which is used now is an unfortunate choice. Because it does create technical problems ...it degrades the performance of a stereo station. Very severely, in my estimation. We've done quite a lot of testing and I think, that since quad is now going to come about, it's time to make some changes in the SCA. We have proposed using 95 Kh. That would eliminate the problems.
H: What makes quad different from stereo technically?
D: In stereo, you have a 38 Kh subcarrier and it simply carries the difference signal-left minus right. The main signal has the sum signal-left plus right. By adding the two, you get left; by subtracting, you get right. You could analyze. it as a
"switch” with the signal going back and forth 38,000 times a second, between the left and right speakers. .. 38 Kh, as they say. In 4-channel sound, the analogy is very similar, only in this case instead of the switch going back and forth, in discrete quad the signal is switched around the room between four speakers, It's a four-position switch. The signal goes 76,000 times a second. But since there are four channels and two are left and two of them are right, the signal spends 1/ 38,000th of a second on the left side and 1/38,000th of a sec-and on the right side. This is why the broadcasting system is compatible. It turns out that the composite left signals are spending that much time on the left and thus would be together in the left speaker of an ordinary stereo stem; same thing with the composite right signals of both front and rear speakers. That's how it works.
H: Is a quad discrete broadcasting system feasible right now?
D: It was feasible three years ago. In 1971, it could have been implemented in the United States.
H: But since that time, there have been several other "systems" enter the fray and currently there are five total systems up before the National Quadraphonic Radio Committee being tested. It seems that some of these other systems have to be in some way similar to yours.
D: I guess I'd better not comment for the record until a decision is made by the NQRC. Naturally, anyway I'd be prejudiced in favor of my system. That's a great question; I really wish the NQRC was past the field tests now being conducted so I could make an official statement.
H: What will be the cost to a radio station to advance to discrete broadcasting?
D: We did some studies in this area and came to the realization that the most inexpensive way for a station to get into quad would cost them about $7,000. That would include two CD-4 demodulators, a 4-channel board, a 4-channel generator, another CBS FM volumax for the station and a modulation monitor.
H: Don't you think it's a handicap that consumers are buying one kind of demodulator now for their CD-4 record systems and then will have to go out and buy another when CD-4 discrete broadcasting becomes a reality?
D: It's unfortunate, but there's no other answer at this time. They are two different systems. They're so radically different that there's no way you could combine the two systems. ICwise, together. Eventually, when the demodulator ICs are available, they could be put in the same box. On your stereo tuner today, you switch back and forth between radio and record; it would be the same.
H: Matrix advocates point out that you don't have to do this with the two matrix systems.
D: But matrix is just a 2-channel system. It's not real
4-channel sound.
