by Edward Tatnall Canby
Midwest Safari
IT ISN'T OFTEN that I get out into the audio field. That sort of travel is for you reps and traveling salesmen and Vice Presidents in charge of . . . er, well, in charge of the field.
I know how you hate traveling. I do sympathize. As for me, I stay at home.
Must I fly to Indianapolis to hear RCA's latest pressings or to Germany to sample Deutsche Grammophon? Everything comes to me on a platter, the P.O. allowing. And so I stay put.
But this spring I had a chance to go on audio safari, and it was good. I am bubbling. Out there in the grass roots, the high Midwest, I picked up more new ideas than I had in years.
I was asked to expound on one of my long-time favorite audio hobbies, binaural sound, at Madison, Wisconsin.
The invitation came most unexpectedly from a new arm of public broadcasting, The National Center for Audio Experimentation (NCAE) at the Univ. of Wisconsin, founded several years back as an outgrowth of the public broadcasting act. Wow! Travel! A working vacation. And a kindly fate pointed to Evanston, just outside of Chicago, where the very day before I could stop off at the Midwest Acoustic Conference, …. all the top quadraphonics people a for heavy argument. Nice little finger also indicated Shure; but Shure's Evanston works were closed down. Saturday.
(At Madison I caught up with a Shure Vice President in charge of Professional Products.) A fateful thumb extended in still another direction-- Buchanan, Michigan. Good idea! So I stopped off at Electro-Voice in Buchanan en route home and almost ran into our Editor in Charge of Everything, who was doing his own safari thereabouts.
To my genuine astonishment, I found at Madison that binaural sound for headphone listening is already quite a big thing in the new area of public radio. I hadn't heard about this development (had you?); in fact, I still thought binaural sound was just one of my private hobbies, like stereo color pix and growing parsley indoors. Right now, something like 80 public radio stations are experimenting with FM multiplex binaural broadcasts directed, not towards loudspeakers, but to the ubiquitous "stereo" phones that are an adjunct to so many home systems. The credit for this definitely goes to NCAE and its present director, Ed Burrows, a long-time radio man whose level headed P.R. on behalf of the headphone idea is beginning to give the medium the place I have always thought it should have in our listening spectrum.
Not just stereo through phones, but binaural recorded specifically for the headphone medium. More on binaural in a later article.
The first large object I saw at the Midwest Acoustic Conference in Evanston was Bert Whyte, in the very middle of the scene, the second being an enormous theater speaker on the stage, right in front of me, with three more set up several miles apart for the quadraphonic demos. Waste of time.
Four-channel sound is not designed for reproduction in large halls with steep, overhanging balconies. So I will tell you nothing about what I heard. Bert Whyte, though, was the Magnecorder man who in 1952 shoved a PT-6 BIN binaural "Maggie" with staggered heads at me and thus made possible my first home-grown experiments in the binaural medium. He was then also heavily into "binaural" and has many first class binaural for loudspeakers tapes in his library from that era which, no doubt, are now correctly classified as stereo. In 1952 we hadn't started using that term.
The Midwest Acoustic Conference was an all-day affair entirely devoted to quadraphonics and the roster of speakers was an impressive, well chosen balance between the top men who had their special causes to plead, for matrix, discrete and so on, and those whose contribution was towards a solid practical/theoretical background on the subject. If there was not too much of startling newness revealed, it was merely because, these days, the quadraphonic principals are on perpetual tour, trailing each other from one public forum to the next, and the sensational can only appear once-the next time, it's the same old speech. E-V's Howard Durbin, in charge of all sorts of things including matrices, suggested they all hire a railroad car (with baggage car attached?) and take the grand tour cooperatively. He even offered me a compartment in the Pullman.
The real revelations for the press at such sessions, you see, tend to come out of the unstructured question periods after the formal talks. In Evanston, at the tail-end of the day, the assembled representatives of every important development in quadraphonics stood majestically on the stage together and got heckled for a fair-thee-well. Something to see and to hear. Miraculously, nobody got really mad, and that night they all set off for Provo, Utah-and intervening whistle stops-still friends.
In that one day, and again at Madison, I picked up some really new insights into the prevailing problems of quadraphonic recording and its vital relationship to the merits of the various reproducing systems. It was interesting to hear three very different philosophies for the mic set-up, along with practical realizations. Marvin Camras, a founder of our audio field, expounded the most theoretical philosophy, that of the phantom living room placed in the middle of a concert hall. An invisible box, its four sides represented by outward-facing microphones in four directions. Transport the box to your living room--i.e., replace the mics with speakers in the same position facing inwards-and you have created sonically transparent walls with time delay. The sound (in theory) just continues onwards from mics to speakers, recreating the original sound field.
As the middle-aged will remember, this is a refinement of the old "curtain of sound" theory by which we explained stereo in its early days; infinite numbers of mics on one side of a curtain across the front of a stage, infinite numbers of speakers on the other side, and the sound goes right through. With delay by recording if desired.
Concepts like these are always fascinating for the roving audio mind, but they tend to infuriate the practical minded recordist who has to work for his money with the mics themselves.
And who wants a concert hall anyway? A lot of people were thinking in concert hall terms at Evanston and the influence of that idea is still obviously enormous. But plenty more people I met on this trip were vociferously anti-concert hall and for lively reasons. This was a major difference that came out again and again.
Milton Putnam, who to my delight turned out to have recorded the recent Stan Kenton two-disc quadraphonic "live concert" jazz album at the Univ. of Utah, was the next man; that album turns out to have been no concert at all, but a ten-hour heavy recording session with students invited to listen in and make appropriately natural background noises. Cleverly done, and the padded seats on hand were the type that equal a human body in sound absorbing, so the variable audience, coming and going, did not appreciably change the acoustic situation. No phantom box of mics here! The Utah mics soared gracefully upwards and outwards from the frontal stage area in two diagonal lines, at three distances, plus accents up front. When somebody tripped on a cable and the far mics went out, the tapes were fixed up later via a Cooper delay line so you can't tell the difference. Interesting.
What struck me as very significant in this highly expert big-time jazz recording session was that the set-up was definitely front-oriented, in a big, live "concert hall"--but in playback, which I had previously heard in my living room, you are surrounded and in the middle of a huge arena with students seemingly clapping and cheering all around you. It is important to understand that we can jockey our quadraphonic sound back and forth from front-oriented to surround sound after the fact, if surround sound is what we want.
But is it? Do we face front, or don't we, as we listen? That is the biggest question in present development, and it is clearly related to the concert hall-or-no-concert-hall argument. It is possible, and often desirable, to record strictly in surround sound with no front, no rear, no sides-an even 360° distribution of sound sources, like theater in the round. Right now, that concept fascinates a great number of the more progressive and active recording engineers in many areas. Who knows, perhaps even concert-hall classical music will some day edge around to this format for our home reproduction? I'd go along. It is entirely possible. We are dealing with a new medium for old music remember, and--given time for adjustment-that medium will certainly develop its own best terms of presentation. It always has.
I get the feeling, then, that the recording people want the freedom to choose their own best route in these respects and I must say I can't disagree.
We have seen enough changes in recording technique to know that even in classical, there will be plenty more.
And audiences to go along with them.
Yet, don't underestimate the concert hall up-front usefulness. After all, we do have forward facing ears and heads and always will. The frontal concept, with sides and back, isn't likely to go away altogether-not until we sprout ears on the backs of our necks. And don't forget, too, that concert hall liveness or ambience is an enormously useful and, indeed, necessary tool in the recording of all music. It has long since, in effect, been divorced from the concert hall itself, as a free agent that may be used naturally or synthesized.
I think that some engineers get unnecessarily het up about the "classical" bugbear. Classical recording, mind you, is already remarkably disembodied and into new techniques, far out and away from any literal concert-hall realism even before we get down to quadraphonics. The classical sound in music such as Beethoven may still seem conservative to the far-out people and, to date, we have not tried to 16-track Beethoven. But we might. In terms of technique in the session, I'd say the classical people are not nearly as far away from the more advanced techniques as they might seem by the sound. We are all going in the same direction.
John Eargle is a musician, and his tricky circuit for converting three channel master tapes into quadraphonic sound is a superb contribution to the art. His presentation at Evanston showed a definitely front-facing layout, and it was clearly ambient inclined too.
Classical? Not necessarily. For one thing, he bends his performers into a half-round and puts two mics quite close together near them, aimed out at about 90 degrees. You can play with that sort of direct sound in your later mix down. For ambience, he goes out 25 feet or so with mics a dozen feet apart, more or less; he stresses the crucial adjustment is by trial, in every session, for a balance between direct and ambient sound. (Reminds me of the old Maxfield formula for maximum mono presence.) Accent mics too, when useful and where useful, according to varying need.
My impression was the Eargle thinking, seemingly classical, actually extends to all sorts of real-time recording and straight on into 16-track mix downs of the pop kind, where the musical elements are recorded separately in time and often in place. No matter! The tools will work. You can end up with front and back--or theater in the …
It very soon became … Evanston and at Madison, where we had a potent little mini-session on quadraphonics, that the front-back idea vs. the equal-sound-all-around has become crucial to the whole matrix vs. discrete argument and, in particular, in the evaluation of Columbia's SQ.
SQ, I now see, is ever so clearly front-orientated in its basic approach. That system laudably preserves a full stereo frontal image which is virtually intact as compared with two-channel stereo. (Vanguard also has promoted this concept since the beginning of their quadraphonic recordings some years ago.) SQ also provides a laudably smooth extension of sound around the sides of your room and back towards the ambient rear. There is no split between "direct" and "reverb" sound.
These things are via my own observations and I find them good, for much of the music I call my own. In terms of reverberent up-front music with a maximum of room sound, SQ is extremely well designed and highly musical.
However, and here's the rub, this smooth front-side configuration leaves a sharp out-of-phase "hole" at the center rear where, so to speak, the two sides meet in back. You cannot place a solo sound at that point; it bounces off to the sides and/or is cancelled by the phasing. Does this matter? That's the big argument.
It doesn't matter much to my ears, for most of the music I hear. I have no special desire to hear a soloist directly behind my head. On the other hand, it matters a great deal to me if in quadraphonic form, I find the vital front spread of stereo sound in any way contracted and less realistic. That's where the musical presence is, up front and very real. Direct side and rear sounds may occasionally be of exotic interest, of course. Berlioz brass in the back corners, big choruses, off at the diagonal. But dead center rear is not--to me--of any great importance.
This, I take it, is the Columbia viewpoint. Again and again Columbia says, who wants a soloist at center rear? Valid argument! From one point of view.
And yet a lot of people are shouting I DO! They want precise positioning all the way around, from every direction, equally, rear-center included. And again, they are likely to say, who wants a concert hall? They are, of course, right. It isn't necessary to think front and rear, and you should at your choice be able to avoid it, and also, if you wish, avoid the idea of the rear channels as mainly for ambience, reinforcing the front. So, you see, SQ has run straight into an elemental aesthetic argument. If I am right, the other matrix people have variously coped with the center-rear so that you can, in fact, put a solo or direct sound source at that point, if you want, matrix it, and decode it at center-rear. In other words, the other matrices tend to be more practically orientated towards sound-in-the-round in their parameters than the SQ matrix. But remember, SQ goes along with the shape of our heads and the direction of our ears. Interesting divergence of outlook.
Space is flying and so I'll end (with much left to say) via an amusing bit of listening I did at Electro-Voice. One of Howard Durbin's colleagues had been experimenting with quadraphonic discrete taping to provide source material, I think, for matrix experiments. He set up a small Dixieland band, brass, sax, guitar, drums, in a deadish studio, and took them down on half-inch professional tape, four channels, with the instruments discreetly distributed so there could be spatial juggling in the playback. The idea was to achieve a neutral sound-in-the-round, equal material in various directions, in order to evaluate matrix handling of the distribution.
We listened. Yep, there they were, each group of instruments clearly coming from a different direction, all around, and the guitar accompaniment squarely at center-rear, via mono in phase feed to the two rear channels. That was SQ, natch.
Rear? What was I hearing? I thought this was to be equal sound-in-the-round? I had to laugh. All unconsciously, as far as I could tell, the man had put the melody instruments in two of the adjacent channels, to make a front, and the accompaniment instruments in the other two, for a rear. Ever so definitely there was a front and back, but the effect was entirely due to the musical sense itself.
I suggested we turn our chairs around and listen the other way. No question! The music was backwards. The main melodic sense was now behind us. The rhythm and chord accompaniment was up front. Crazy.
So you can begin to understand that the idea of equal sounds all around and the front-back idea are merely first cousins, related but no siblings. They can work together. And ambience, when you come down to it, is a neutral factor that can go either way too.
Ambience to define a hall via the rear sound. Or ambience to define an all-around space with equal billing in any direction, and no front at all.
So--my Midwest safari was worth its weight in travel gold and I'm going to have to wangle a few more invitations like that. Just send 'em to me special delivery.
(Audio magazine, Jul. 1972; Edward Tatnall Canby)
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