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The following is the second in a series of transcripts from Contributing Editor Harry Maynard's Men of Hi Fi program, which is presented on New York City radio station WNYC-FM, 93.9, on Sundays at 10:00 p.m. His guests for this program were Thomas Lott, president of Quadracasting Systems; Jerry Orbach, marketing manager of JVC America, and William Halstead, vice president of R.T.V. International.
Maynard: Good evening, ladies and gentlemen. We are going to give you a special report on the status of discrete four-channel stereo broadcasting. My guests are Tom Lott, who's president of Quadracasting Systems, Inc., San Mateo, Calif.; Bill Halstead, vice president of R.T.V. International, sometimes called "Mr. Multiplex" in this industry since he's been through the whole stereo broadcasting bag, and Jerry Orbach, marketing manager of JVC, the people who developed the first discrete four-channel record.
Tom, tell us where the Dorren quadraplex system stands right now? You've done some experimental broadcasts at K-101, San Francisco, and I want to remind our audience that we are going to play some off-the-air tapes from two radio stations. I don't want you folks out there to get disoriented and think you've suddenly been transported to Toronto, Canada, or San Francisco, because we play these off-the-air tapes showing you how this system worked.
You can hear it in two-channel stereo only, of course, but you will be able to determine its compatibility and get some idea of the quality. But tell us where things stand, Tom.
Lott: We conducted tests on K-101 in San Francisco just over a year ago with special permission from the FCC. We ran tests for 60 days, making all sorts of measurements and broadcasting music to allow listeners to see whether they could detect any deterioration or change in their normal stereo reception. The whole point of the Dorren system is that it is fully compatible with existing equipment.
The stereo listener gets the full stereo, just as he does now, and does not lose any of the two-channel material.
Maynard: K-101 even ran ads in San Francisco newspapers and asked the listeners of this broadcast to determine if there was any change in quality or whether they noticed any differences.
Lott: We also had some very interesting results in the tests, which I concluded in Toronto, where I flew from just yesterday. With the permission of the Canadian government, we ran tests on CHFI, which is a 420,000 watt station in Toronto. Two sets of tests really, one at night for the benefit of the Canadian government monitoring stations which were taking all sorts of measurements on the system and are going to give us a report which apparently from the initial indications from them is very favorable. They confirm what we have said, that the system does not take up any more bandwidth than a standard two-channel stereo system. In actual fact, it takes up a little less.
Maynard: Can you tell us how the Dorren system works basically?
Lott: Well, it's really a simple extension of existing two-channel stereo. The existing two-channel stereo had a 19 kHz pilot signal and a 38 kHz suppressed carrier double side-band signal, giving you the difference information. The 38 kHz signal carries the left minus right, and by simple mixing processes of addition and subtraction, you can then separate left and right.
Maynard: This is sort of a synchronus quadrature in a certain sense, isn't it? Instead of breaking the signal up into two parts, you break it up into four parts?
Lott: Right, we take the left-front and left-rear, the right-front and right rear, and we broadcast all four added together as the main channel so that the mono listener gets full mono. He hears the sum of the four. On the 38 kHz subcarrier, which is the same in standard stereo, we broadcast the two sets of difference information. We actually put two sets of information in quadrature with each other on the 38 kHz, and the fourth set of information we put on a 76 kHz suppressed subcarrier double sideband transmission, but at 76 kHz locked to the 19 kHz pilot, just the same as the 38 kHz is locked to the pilot. So the stereo listener gets his full stereo and the four-channel listener can receive all four channels with a separation up to 45 or more dB from any one channel to any other.
Maynard: What about bandwidth? Does it take up any more bandwidth than an ordinary stereo transmission?
Lott: No. The initial reports from the Canadian government monitoring station confirm what we have been saying quite a long time--that we do not take up any more bandwidth. In fact, that it's very much the same as when stations went from mono to stereo, and people found that interference between adjacent stations went down, not up.
People say that with stereo having all this information, you are going to have more adjacent channel interference, and this turns out not to be so. Technically, it's very complex because of modulation indexes and I don't want to get into things that technical here since it would take a lot of mathematical explanation.
We did however produce as a result of the 60 days of testing in San Francisco a very comprehensive report, which is not quite as large as a Manhattan telephone directory and certainly as large as the San Francisco directory. It showed a compilation of 50,000 pages of computer print-out where we had all the different bandwidths for mono signals, stereo signals, and four-channel stereo signals under every possible condition of modulation.
Maynard: What feedback did you get from the ordinary listener, who obviously had to listen to this in two channel stereo?
Lott: In San Francisco and especially in Canada (because the tests conducted Tuesday night used equipment which had been improved over the equipment we used at K-101 a year ago), we had calls from all over the place saying that their stereo had never been so good. We had a call from almost 150 miles away from cable TV system operators who said that the stereo quality and the separation was the best that they had ever heard. It was so good that they had put it on their cable system and told their listeners to listen to it. "
Maynard: We are getting this sort of feedback ourselves when we broadcast four-channel matrixed sound Jerry Orbach here calls [...] channel. Jerry, what's happening in Japan? Are the Japanese doing any experimental broadcasting using the Dorren system?
Orbach: Well, not at this time. But the Victor Company of Japan, which is the parent company of JVC, is in very close contact with Tom and Lou Donen. It looks as though we are going to get permission to make an experimental broadcast in Osaka, Japan, very, very shortly.
Maynard: Good. I want to remind our listeners that if all goes according to plan, in March, through an arrangement with WKCR, the Columbia University station which is also non-profit, both stations are going to hook up and for that month give you discrete four channel broadcasts at 9:30 p.m. every Monday evening for 25 minutes. Then we are going to do a broadcast at 2:00 p.m. every Tuesday afternoon so that the many people who can't find an extra stereo receiver can go to their favorite hi-fi dealer, who ought to have an inventory of at least two stereo receivers, and you will be able to listen to four-channel stereo there. The last time we did this two and a half years ago, over 80 hi-fi stores in greater Manhattan tied in and used it as a traffic builder to get people interested in four channel to come in and hear it.
This will, however, not be using the Dorren system which comes right off one transmitter. Bill, you were involved with me in the early discrete four channel broadcast. We were the first ever to do it in the United States.
Boston had done it, but only broadcast the two front channels. What was your reaction when we did this broadcast, Bill?
Halstead: I of course listened at the station and the impression was, and all the engineers there agreed with me, that the improvement brought about with the use of four channels was just so great that there was no comparison with what we were getting in two channels. My family was listening at home and we simply had our normal two channel receiving equipment plus two simple portable units and the minute we added those two extra channels by means of the portables, everyone heard a very great improvement, not only in terms of quality but in terms of location.
Maynard: As a matter of fact, a lot of people just got a simple mono FM tuner and tuned in WKCR for the rear of the broadcast and noted tremendous improvement. I had heard four-channel stereo demonstrated before, and you can go down to the Acoustic Research [...] in Grand Central and hear it--effective. But I think four intimate, that it works best in an intimate environment where you don't have a lot of people competing with it. This is why, for example, when your friend Jim Gabbert of K-101 broadcast your system at the National Association of Broadcasters meeting, it was the usual impossible demonstration.
Not that there was anything technically wrong with it, but the room was filled with 400 people, all turning around, standing on chairs, etc., making more noise than a herd of mating elephants.
The first time I ever heard four channel correctly was off the original broadcast we did here when I took a small stereo FM portable receiver and put it in the rear of the room. And I knew that I was not suffering from auto hypnosis when we got over 100 letters, everyone of them a rave, talking about how superior it was to their ordinary two channel.
Has that been the impact on the West Coast too with the people who heard it? Loft: Yes, Harry, very much so, especially when they have heard it under ideal conditions in the living room and not in a large hall. The difference between the two channel and the four channel and the four-channel discrete and four-channel matrix shows up very strongly with some materials. Of course, some of the material when matrixed sounds pretty good in four channel, but some things you can only do with a discrete broadcast.
Maynard: What are those things, Tom?
Lott: Well, certain types of music, which they are deliberately writing now, where they want people in the middle of the instruments. Some of the rock music.
Maynard: Or theater in the round. Basically, it's where they want a separate, clearly defined voice on each channel. (General assent.)
Halstead: What I would like to bring out, and I think it's probably important that it be developed, is that we have a problem with the FCC. Going back to the development of ordinary stereo, the first tests were run in 1950. The improvement in quality that we obtained with the two channels was just tremendous, just as the difference is today with four channels. But the Commission, when I went down to talk with them and ask that we be given a grant for normal use, said, "Well, this is going to take four or five years, because we have treaty obligations and things of this sort." Actually, it did take five years from 1950 when the first stereo was tested here in New York to the first grant of SCA (Subsidiary Communications Authorizations for background music service-that was in 1955), then it took another five or six years before stereo was approved by the FCC because they had to test different systems, make evaluations, and finally the FCC had to act. And I'm afraid we are going to have the same problem here.
Maynard: Good, I think this is an excellent point. This is why I feel that the fight between matrixed four channel and discrete four channel is an artificial one. I believe that for the next three or four years matrixed four channel sound is a big enough improvement over two-channel sound and is a natural bridge to four discrete channels, that I don't want to go without the benefits of matrixed four channel for that period until the FCC finally does make up its mind whether it's the Dorren system of quadraplexing or some other. I want to have the benefit and the added improvement of four channel stereo in the interim. But my question, Tom, is how soon is the FCC going to act on this, in your opinion?
Lott: Well, as you know, with a government department, it's very difficult to say. They are very restricted in their budgets, and the time it takes to get something done is very difficult to predict. However, I don't think it's going to take quite as long as last time, because last time we started off with about 17 systems, then it was gradually weeded down to six.
Maynard: I am wondering if right now there may be some bright guy like Lou Donen out there who has got an alternative system of discrete four channel broadcasting. Frankly, when I talked to a prominent FCC official about this, he said, "We are going to close the door. We want to get as many different proposals as possible as to how to broadcast discrete four channel." But as we demonstrated on this show with the broadcast using the Scheiber method, there are no unfortunate side effects. Therefore, from now on,: everybody's broadcasting matrixed four channel sound without calling up the FCC and getting approval. The official did say that if we freeze this now, how do we know there won't be some new system that may even be better than the Donen system, even though the Dorren system might have proved itself to be a very satisfactory system. And what does your system do when a station wants to continue to use its subcarrier and derive some commercial income from it?
Lott: Part of our large report, which I mentioned that we had submitted to the FCC, suggested a possible solution to this problem. I don't know how many of our listeners are aware but any station with an SCA system on it cannot give you really good stereo, because the third harmonic of the 19 kHz pilot-57 kHz-beats with the 67 kHz of the SCA and gives you a 10 kHz whistle. So that if anyone listening to a stereo station with SCA on it has to have a filter on his set which cuts out everything above 10 kHz and he will not get really good stereo. He's losing all the high frequency response so that the really good stereo stations are not running SCA as well.
Maynard: And the station has to back off about 10 per cent of its power, doesn't it?
Lott: Yes, you have to back off a little, but the main difficulties are the beats and interference caused by the SCA system to the stereo system. With our system, you cannot leave the SCA system where it is, but we have made suggestions as to how to solve not only the problems of putting SCA together with four channel but also as to how to solve the problems of existing SCA interference.
Maynard: Is this very complex to go into?
Lott: No, it's very simple. We simply move the SCA carrier up to 114 kHz and phase-lock it to the 19 kHz pilot.
Because of the low modulation index up this far from the center carrier frequency, you do not cause as much adjacent channel interference as you might think from having something right out there.
Maynard: Do you have any comments, Bill?
Halstead: Having gone through the early problems with the SCA, I'd say that the people who use SCA for business, such as Muzak, will probably object to any arrangement of this type because it will require new receivers and this is a real problem in a large city, such as New York, where they would have to change 1,000 to 2,000 receivers to operate on a new frequency.
Maynard: Tom, you're shaking your head.
Lott: I was only thinking that it doesn't require new receivers. It requires a filter which is only a $4.00 or $5.00 item and usually a plug-in one. So it's not a major thing. We are not suggesting that they change the SCA frequency, but that they put in an additional one at 114 kHz so that those stations which want to go four channel can do so and still have SCA if they wish. What I am really suggesting is that most of the stations using SCA will not want to go four channel anyway.
Halstead: You're probably right.
Maynard: As a matter of fact, I did a study when I was editor of FM Guide, and I discovered that only four or five stations out of about 60 FM stations in the greater New York area were even using their subcarriers from Muzak. Another thing I discovered was that some of the better stations, such as [...] "'le FM and so forth, told me that they 'given going to stop using the […] now that FM has gotten quite successful, especially for stations such as WRFM, they were not going to give their listeners anything but top-rate stereo quality.
Lott: Our proposal for SCA would allow those stations who are really proud of a good stereo signal to put on an SCA subcarrier without any determent to their quality. No filters, no nothing. I think this would enormously increase the usage of SCA. Jim Gabbert of K-101 said that under no circumstances for no amount of money would he ever put SCA on his station because of the interference to his stereo. But he would, he said, be happy to try the 114 kHz subcarrier because if tests and calculations are correct, this has no effect on existing stereo.
Maynard: Let's give our listeners some background on this tape we're going to hear now. There's going to be a Canadian announcer, so don't think you're in Canada or that you had some LSD thrown in your water system.
What are we going to hear, Tom?
Lott: These are excerpts from a broadcast made January 18th, Tuesday, in Toronto, Canada.
Maynard: And how far away was the reception of this off-the-air tape?
Lott: About 15 or 16 miles away. This is a four-channel off-the-air recording which tonight's listeners will hear in two channels. The two left channels are mixed for left and the two right channels are mixed for right.
(Tape of broadcast played.)
Maynard: Now, Tom, you wanted to comment on this broadcast from Toronto, Canada, of which we just heard a tape?
Lott: I just wanted to say that we used the JVC record to provide part of the music for that program. The whole of four-channel stereo broadcasting, of course, is going to open up as records become more and more available, and we feel it's going to very shortly. Lou Dorren, who invented the four-channel broadcasting system, has also done some work and JVC has done considerable work on decoders for the record. And a lot of earlier problems with wear, separation, and things like that, have now been solved. I think that very shortly you are going to find that four-channel discrete discs are very much available. And this will give impetus to the broadcast field because so far the FCC has not been pushed for approval since they have a limited budget and there's no great pressure to provide a system because the software is not available. If we had the broadcast system today, what would we broadcast? There's some tape but not much. However with the coming of the disc, then we'll have something. Harry, you made a comment about the matrix system, which both Jerry and I want to re-butt. Our feeling on the matrix system is that it has a very valid place in four channel stereo, which is to allow people to play their existing two-channel material and get some semblance of four channel out of them. They sound much better through a matrix decoder than they do played straight two channel. However, we strongly disagree with the broadcasting of it because we've done a number of experiments with different types of matrix discs and the system is not fully compatible with mono. If you listen to a matrix record which has material in the center rear, this completely disappears in the mono. I have a record in my briefcase of Barbra Streisand with instruments in the center-rear. When listened to in mono, all those instruments disappear so that the mono listener wouldn't hear them.
Maynard: I just want to comment on this. We have been broadcasting four channel matrix for over two years now and in the last six months, we have had 25 minutes every Monday night. We have never once gotten a letter and I challenge any listener who only listens in mono to send us a letter telling us that he has found any of the matrix four channel incompatible. Jerry, the microphone is yours.
Orbach: Well, of course, I agree wholeheartedly with Tom. I would say that probably more of your listeners have FM stereo at home and Tom's remark was more or less directed to the mono listener or that you probably have very few.
Maynard: You mean you want to protect minority groups. I know your type.
Orbach: And secondly, of course, unless you have heard the original recording, it's sometimes very difficult to know whether the sound you're hearing is degraded or the original sound. But I think that any so-called improvement should be an improvement and should not pull down this type of sound. Therefore if the customer realizes it or not, his sound should be as good as it might be.
Maynard: I think very candidly that this is a nit pick myself. If somebody who really cares about hi fi is listening monophonically, he can't make any A-B comparison anyway or he would have gone to stereo 20 years ago. As Ben Bauer said, you're going to have relatively fewer recordings where they are going to put a significant amount of material in the center-rear channel.
The impression I got from the FCC official was that one of the reasons they wouldn't want to freeze it was they couldn't be certain. You proposed a system for four-channel broadcasting, and both you and Lenny Feldman agreed that the Dorren system is the better system. We applied to the FCC to broadcast your four-channel system, and I remember both you and Feldman saying, "Well, they beat us. They've come up with a system that's better, it's more natural, it's simpler, it's more elegant, it's the economy of least effort.
What's your comment on that, Tom?
Lott: My comment is that we would like to see any good system of four channel discrete broadcasting adopted. We of course would prefer our own, but we feel we would like the FCC to at least put out a proposal asking for submissions for other systems. We don't feel we should sit there for another four or five years to see if anybody can come up with a system as good or better.
Maynard: Let's let our listeners hear some more four-channel sound. Once again taped off-the-air, isn't it?
Lott: This was picked up about 15 miles away from San Francisco station K-101, using a low-cost tuner fed into a small Dorren four-channel decoder and recorded with a Sony tape machine.
Sorry about that, Jerry. At the time we didn't have one of the good JVC machines we now have. This was recorded in four channel, but you're going to have to listen to it in two, so you won't be able to tell the tremendous separation. There is one initial number where there are different groups of instruments coming from each of the four speakers. And you can hear them out of one speaker, but if you go and put your ear to the other three speakers, you cannot hear the instruments in the fourth speaker, the separation is so great.
(K-101 tape played.)
Maynard: I think there has to be one thing made clear, that four-channel stereo is not just an added gimmick or just a nice improvement. In my opinion, it's a bigger development over two than two was over one.
Orbach: There is no question about that. The only people that call it a gimmick are those who never heard it. Once you've heard it properly, there can be no question that it's the greatest improvement that's ever been developed in sound. It isn't even close to stereo and has nothing at all to do with mono. Once you've heard four channel, you cannot listen to anything else again and be satisfied.
Maynard: Everybody who has been to my living room has said, "This is going to cost me some money, Harry." That's what they have said, when they heard it demonstrated properly with some halfway decent demo material.
(Audio magazine, May 1972)
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