THE ART OF RECORDING THE BIG BAND
by Robert Auld
(This paper is in two parts. The notes for each part are included on the same page as that part. Notes are indicated by a number in parenthesis.)
[This is a revised version of this paper. The first version, published on my web site in 1997, contained numerous historical and technical inaccuracies which have been corrected in this revision. I have also added some new material. -- R.A., 2012]
The jazz big band was born in the 1920's, came of age in the 1930's, enjoyed its greatest popularity in the 1940's, and went into popular decline in the 1950's. In the 1960's the big band enjoyed a comeback of sorts, but was displaced from the front pages by The Beatles and other things. In the 1970's it looked like the big band would either expire, or be transformed out of recognition. And yet, it persists; people still play in big bands, still dance to them, still record them. It has proved a most durable ensemble.
My interest in the big band dates from childhood. My father was a Benny Goodman fan, so I grew up with his music in the house. I became a musician myself, and so I got to play in big bands. I was interested in audio recording, and I tried recording big bands. I was not very satisfied with the results. So, I paid attention to how others were doing it. Some of what I have learned over the years is set down here.
Part 1 of this paper traces the history of big band recording, from the 1920's up to the mid-1960's. Part 2 deals with the changes wrought by the introduction of multi-track recording methods in the mid-1960's, the problems those changes caused for big band recordings, and some suggested remedies. Part 2 closes with the analysis of several modern big band recordings.
[As of May, 2012, The Art of Recording the Big Band, Part 3: Recording the Beantown Swing Orchestra has been added. This segment details a modern big band recording session I engineered, using studio miking techniques similar to what was typically done around 1960.]
I know what I mean by "big band", but you may not. To avoid confusion, we need a common definition. In my opinion a "standard" big band consists of:
The "standard" instrumentation is, approximately, the composition of the Glenn Miller Orchestra, the most popular of the swing-era big bands. "Stock" big band arrangements usually follow this instrumentation.
(Here is a link to a diagram showing a big band setup for live performance typical of the swing era: three rows of horns, with the rhythm section to the left, and a microphone in front for vocals and horn soloists
Common variations in big band instrumentation have included reductions (Benny Goodman initially used only 3 trumpets and 2 trombones for a five-piece brass section), or various doubles and additions, such as:
Rhythm: vibraphone; various latin percussion including congas, bongos, etc.; even tympani on occasion. Since the 1970's, bass guitar has often substituted for the upright bass.
Reeds: it is very common to have the saxes double on soprano sax, clarinet and flute. Bass clarinet, oboe and bassoon have been used occasionally.
Brass: flugelhorn is a common double for the trumpets. Tuba is sometimes added to the trombones. From 1 to 4 french horns have been added. In multiples they are usually treated as a separate section.
Big bands have also included string sections, vocal groups, accordions, rock guitars, synthesizers--in short, just about anything you could possibly imagine. My emphasis will be on the ensemble as it is classically understood, with glances at various additions, as needed.
Acoustic recording could not reproduce the full frequency range of instrumental tone. Therefore, it was common to alter the instrumentation of ensembles to suit. For example: tuba was usually used in place of string bass, and drummers would discard their bass drums and use only higher pitched instruments like wood blocks and cymbals.
When electrical recording was introduced in 1925, these practices continued for awhile. Due to a lack of good playback equipment, many engineers did not realize at first that the new technique could actually reproduce a much greater range of tone. Fortunately, this changed fairly quickly.(1)
From about 1928 on, instrumental groups recorded with the same configuration as they used in live performance. Ensembles were balanced by grouping the musicians at various distances from the single recording microphone. A musician taking a solo would walk up to the mike and play into it, then move away for ensemble passages.
Instead of "big bands" it would be more appropriate to talk about dance orchestras. The larger ones were evolving into what would become the big band of the 1930's. (2)
The musical style that became known as "swing" evolved out of the dance music of the 1920's. It did not really attain recognizable form until about 1930. Dance orchestras at the turn of the decade were tending towards the "standard" big band configuration, but took a few years to settle into that form.
Electrical recording was still at an early stage of development. The great range of equipment that we are accustomed to today did not exist then. Studios independent of record companies or radio stations were rare. In any case, studio electronics were often built in-house, and elements that could not be easily built (microphones, disk cutting lathes, etc.) were obtained from a few large suppliers such as RCA or Western Electric. Much of the equipment was developed with the needs of the film and radio industries in mind, but was readily adapted to the needs of record studios. (In fact, recording sessions were sometimes done in radio studios, as most of the usual equipment was already at hand.)
Remote recordings were usually associated with radio broadcasts. Again, the same standard-type equipment was used. Therefore, the signal chain for almost any late 1930's big band recording might be as follows:
-One or two microphones, typically either dynamic element, omni-directional pattern (the Western Electric No. 618A, for example) or ribbon element, bi-directional pattern (RCA type 44, for example).
-Console, custom-built, or a modified broadcast board. Four microphone inputs would be about as extravagant as the designers would get, in most cases. Mono output.
-Disk cutting lathes, either 78 rpm or transcription format. Commercial 78 format was a 3 mil (3 thousands of an inch) groove cut laterally, disk size up to 12 inches. Professional transcription disks, as first developed by Bell Labs in the early 1930's, were vertical cut ("hill and dale") with diameter up to 16 inches and were recorded at 33 and 1/3rd rpm for more playing time. RCA subsequently introduced lateral cut transcription disks of the same diameter and playing speed, with a groove width of 2.5 mils. The lateral cut format eventually supplanted vertical cut disks and was used in radio stations into the 1950's. 16 inch transcription disks, whether lateral or vertical cut, could hold about 15 minutes of material per side and were commonly used for delayed broadcast of radio shows.
-Signal processing (equalization, dynamics, reverb) was initially available only in very primitive form. For example: electrical disc cutting used pre-emphasis to reduce surface noise and allow greater playing time. In some cases, the engineer would alter the crossover point and/or slope of the recording emphasis of a given disk if he felt he would get a better result that way. Therefore, playback curves for electrical 78's tended to be nominal (which poses problems for restoration of such recordings).
-Dynamics were controlled by manual gain-riding, moving the microphone, instructing the musicians to play louder or softer. Limiters were used on broadcast networks from the late 1930's on, mainly to avoid overmodulation (which was against FCC regulations). Compressors and limiters were not widely available to recording studios until after World War II.
-Reverb was usually a matter of the room one was recording in. At least one film studio had spring-type reverb units custom built in the mid-1930's, but outside of Hollywood or Bell Laboratories such experimental equipment was hardly even thought of. Radio serials, with their need to portray many different locales, inspired the first live echo chambers (often, converted bathrooms or stairwells). Such enhancement was not usually available or even considered desirable for straight music recording until the 1940's.
Despite the limited equipment available, the better records of the period give a pretty clear picture of how the swing-era big bands sounded. The best engineers of the time had an impressive feel for what was important in the music and were able to capture the essentials. And the simplicity of the methods they used insured a certain honesty in the recordings. With no overdubbing, no splicing, and very little in the way of tonal enhancement, what the musicians played is what you get.
The most famous big band recording of the swing era was a live concert remote. In some ways this recording is not typical of its time; it was not an aircheck of a radio broadcast and no one was intending to make a commercial recording. The full story of how Benny Goodman's 1938 concert at Carnegie Hall was recorded is convoluted and the details of what happened to the disks over the years are worthy of a detective story. For my purposes here, I shall recount only the bare technical details.
The recording of the 1938 Carnegie Hall Concert resembled the remote airchecks of the time. Two microphones were used, one hanging over the stage for overall pickup (an RCA 44BX, normally used for New York Philharmonic radio broadcasts), the second on stage and also used for the P.A. system (a Western Electric 618A on a floor stand). These two sources were mixed on the site and the signal sent to CBS master control at 485 Madison Avenue, using the usual broadcast-remote transmission line. (This was a high quality telephone line, probably with response up to at least 12 kHz or so.)
Independent studios could subscribe to direct lines from the major networks and local stations for the purpose of making aircheck recordings, which were needed by many people. In this case, Albert Marx (a producer for Brunswick Records at the time) hired Harry Smith, who had a studio at 2 West 46th street, to make the recording. Smith took a feed from CBS master control and used two 78 rpm turntables to record the concert on twenty-eight 12-inch disks. A few weeks later, Benny Goodman arranged for a set of copies to be made. He kept the disk copies and, eventually, forgot about them.
In 1950, Benny Goodman rediscovered the disk copies of the concert in a closet in his apartment. This led to the first commercial issue of the concert in 1950 by Columbia Records. Howard Scott, a producer with CBS Masterworks, oversaw the project. The lead engineer doing the disk to tape transfers was Bill Savory. He had attended the original concert and used his own copy of the concert program to insure that the recording would reproduce the original sequence of the music. The tape dubs made in 1950 were the source for all subsequent reissues until Sony reissued the concert in 1999, under the supervision of Phil Schaap. Starting in 1996, Schaap and Sony tracked down the original 78 rpm discs, which were used for a new transfer to digital format.
Besides its historical and musical value, this recording teaches us about something else: the live acoustical balance of Benny Goodman's band as compared to the balance heard on their studio recordings. The brass and drums really tend to dominate the mix. The relatively distant placement of the overhead microphone lets us hear this clearly and confirms the critical consensus about Goodman's band: it really was louder and brassier than what had come before; a fact that caused Goodman problems with some hotel ballroom managements early in his career. (3) Also evident is the wide dynamic range of the music, which often threatens to outrun the limits of the recording equipment.
In the studio the engineers frequently placed the softer instruments much closer to the recording microphone, the result being an apparent reduction in dynamic range. But in this live concert the true capabilities of the classic big band were on display. It was (and is) a formidable ensemble capable of extremes of dynamics, which arrangers readily exploited. The recording methods of the 1930's could only give an indication of what was there, and the tendency of studio big band recordings, even now, is to reduce the range between loud and soft. (4)
In the 1940's several developments radically changed the technical basis of the recording industry. For consumers, the introduction of the 33 and 1/3rd rpm microgroove LP in 1948 was the big development. This would not have been possible without technical work that had begun much earlier.
RCA had tried to introduce a long-playing record in the early 1930's. It failed for several reasons, chief among them the unsatisfactory consumer playback equipment. The phonograph cartridges of the time required very heavy tracking forces, which caused excessive wear on the long-playing disks. RCA also had difficulty manufacturing turntables that could handle the slower speed without excessive wow and flutter. And the source material for the new disks was obtained with the same recording techniques used for the production of 78's. Given all this, the sound quality of RCA's 1930's LP was not a step forward. (5)
The phono cartridge problem was first tackled at Harvard in the late 1930's. A team of engineers there developed high quality disk recording systems. The need to play back the resulting disks without damaging them led to the development of new cartridge designs. This work established the basis for the modern phono cartridge. (6)
The source material problem would eventually be addressed with the introduction of high quality magnetic tape recording. While there were attempts to develop tape recording in the U.S., the results were not of high quality, and were used mainly for spoken voice applications by broadcasters. (7) But in Germany, during the early 1940's, high quality machines became available, even including some experimental stereo machines. (8) Due to the on-going war, we had no knowledge of those developments. So when the tape machines were discovered at German radio stations after the war, it was something of a shock.
Among those shocked by what they heard was John Mullin, an American Army Signal Corps officer. It was part of his duties to investigate German broadcasting installations. He heard the Magnetophons (as they were called) at a station near Frankfurt, and was so impressed with their sound quality that, after arranging to turn the machines over to the signal corps, he scrounged a couple of machines for himself, took them apart, and had them shipped back to the U.S, along with some recording tape.
After he returned home from his tour of duty, Mullin assembled the machines, improved the electronics, and arranged to demonstrate them for several recording and broadcast professionals. The first development was the recording of Bing Crosby's radio show on the Magnetophons. This experiment was so successful that Crosby's producers decided to use tape as the initial recording medium, instead of transcription disks, for all future shows. (The shows were still distributed on disk as before, but tape editing and copying were used for the preceding production steps.) The second development was the production of what was in many ways a copy of the AEG Magnetophon design by an American company that specialized in the production of precision electric motors. The company was Ampex, and the new machine was their first professional recording product. (9)
The remaining impediment to the introduction of the LP, the manufacture of a satisfactory consumer playback machine, was solved by advances in precision mass-manufacturing in the years since RCA's first attempt. When Columbia introduced their own LP in 1948, they contracted Philco to produce an inexpensive turntable that did a competent job of playing the new records.
The new medium had far lower noise and distortion than the old 78's. Sonic details that were considered of little importance for 78 production (such as acoustical ambience) assumed new importance in recordings made for LP issue. The immediate effect was a general upgrading of the quality of the recording chain, with more attention paid to studio acoustics, reverb devices, etc.
Microphone placement practices for big band sessions changed only incrementally in the early LP era: there would be an overall pickup mike, spot mikes on the piano and the bass, a mike or two for soloists; a total of 4 to 5 microphones was typical. (10)
(Record company executives were not, at first, certain if the public would take to High Fidelity. It took psychoacoustic experiments by Harry F. Olson, VP of RCA labs, to convince them. See note (11).)
In 1955 the Hollywood film industry began to promote a new film about the life of a musician who had become an American icon: Benny Goodman. As a tie-in, Goodman's record label, Capitol Records featured "Mr. Benny Goodman, in brilliant new high fidelity recordings, made especially for this album of the selections featured in the motion picture of his life, The Benny Goodman Story..." In his liner notes for the album, George T. Simon, after noting the authenticity of Goodman's recreation of his old repertoire, declared: "Only one thing is really different: the sound. And how remarkably different too!" In short, the technical sound quality of the recording was considered an important selling point.
This was not new, but the degree of importance was. In the 1930's and 40's, the conditions of playback enjoyed by consumers were usually so poor that even if a given company's records were exceptional in the engineering, few were likely to notice. By the mid-1950's, the situation had changed sufficiently that the promotion of "Hi-Fi Spectaculars" was a common element of marketing recordings.
"The Benny Goodman Story" gives us the opportunity to compare the studio practices of the mid-1950's with those of the mid-1930's, using identical repertoire, played by many of the same musicians. (12) The first impression of such a comparison will tend to vindicate George T. Simon. The newer recording has a smoothness and clarity that is startling when compared to the old 78's. There is some evidence of a more complex microphone set-up: the saxophones sound separated from the brass, an impression confirmed by the engineer raising or lowering their relative volume a bit here and there. The bass and piano have a clarity usually associated with close microphones. And yet, what I find most impressive is the similarity of the sound to the older recordings: the balance between brass and reeds is as before, the drums tend to be in the background, Goodman's clarinet is solidly in the foreground.
Some of this similarity may have been enforced by Goodman; by the time he was in his early 20's he was already an experienced studio musician who was known for having a keen ear, and at no time in his career was he reticent about insisting on what he wanted. If he didn't like what he heard on playback, we can be certain he would let the engineers know about it. But I don't think he had to intervene all that much. In this and other recordings of that period, there was a basic engineering consensus on how a big band should sound on record. That consensus was based partly on how a big band sounded in live, unamplified performance, and partly on the characteristics and limitations of playback equipment of the time. The goal was to create a plausible musical illusion for someone listening to a monophonic LP in their living room. As compared to a monophonic 78, the differences were mainly ones of detail, to accommodate the different limits of the respective disks.
This basic consensus would hold up pretty well until the late 1960's when there would be a great unraveling, for reasons that I shall detail later on. But now, it is time to consider where the engineering action really was in the 1950's. The consumer was not aware of it yet, but developing behind the scenes was--Stereo.
After World War II, the introduction of tape recording made the recording of stereo masters a practical possibility. The first major record company to pursue this in a big way was RCA, largely due to the efforts of John Pfeiffer. (14) The initial RCA stereo program was confined to classical orchestra recordings. Given the large amount of money spent on any orchestra session, adding a second engineering team to record the session with the new stereo equipment was a reasonable expense. And it simply makes sense to focus your best technical efforts on the flagship product. For RCA, the jazz big band was a part of popular music, and could not command the kind of attention and expenditure that went to the Red Seal classical program. The cultural shift that would change all that was many years in the future.
In 1957, when it became clear that the stereo LP would soon be introduced (the necessary disk cutters and playback cartridges were known to be under development), adapting the standard big band setup to the needs of stereo proved to be simple. The sax section (which already had its own mike or two) was placed on one side of the stereo picture, the brass were placed on the other side and the rhythm section occupied the middle. For many studios, this meant virtually no change from their monophonic setup practices. This helped ensure mono compatibility, which was very important, as the vast majority of consumers would still have mono playback systems.
Most stereo recordings of the late 1950's to early 1960's were mastered on three-track tape machines. Ampex introduced their first 1/2 inch, three-track recorder in late 1954, and it soon became the standard of the industry. Why three tracks? The initial reason may have been that nobody yet knew how many channels the eventual consumer format would have. According to Bell Labs, three channels were superior to two, especially for establishing a firm center image in the sound picture. They considered two channels a compromise that would work in less critical applications--home playback, for example. The sales potential of the stereo LP, which could only accommodate two channels, settled the matter. Still, the three-channel recorder continued to be the session recorder of choice until the early-1960's. That third track was so useful for stereo production that returning to only two tracks was not considered.
In 1960, Capitol Records recorded "Sinatra's Swingin' Session" in their Hollywood studios. Sinatra was accompanied by a big band augmented with a string section, all under the direction of Nelson Riddle. The record jacket cover featured a photo taken at the session that, apart from some staged details, shows us the studio setup.
Sinatra's position in the photo is obviously for the photographer; I doubt that the engineers would have had him stand in front of the brass section! But for the rest, the conservative section-by-section pickup is evident: the brass to the right in two rows, picked up by a single mike, the saxes to the left, grouped around a single RCA 44, the rhythm section instruments roughly in the middle with single mikes for each instrument, and the strings some distance to the left with perhaps two mikes on them.
What we hear on the record corresponds to the visual picture almost exactly. There is some audible leakage between mikes, but the matching of the stereo picture to the actual placement of the musicians prevents any strange effects. Finally, the presence of some "spread" in the stereo placement of the rhythm instruments convinces me that the "middle" recorder track was reserved for Sinatra--a wise choice, given the demands he might make.
Listening to this record, it is clear that important elements of the engineering consensus survived the introduction of stereo. The balances between the brass, saxes and rhythm instruments are similar to Benny Goodman's 1955 sessions. And in one respect nothing had changed: the consumer product was still the LP, with its familiar limitations.
Two years earlier, Miles Davis and Gil Evans recorded "Porgy and Bess" in Columbia's 30th street studio in New York City. The 1997 Columbia/Legacy reissue (CK 65141) has a photo showing part of the setup for one of the sessions. Miles Davis is in the foreground, the trombones can be seen just beyond to his left, and the french horns are beyond the trombones, facing them at a 45 degree angle (which causes their backwards-facing horn bells to fire well away from the other brass). A single mike behind the horns picks them up, another mike picks up the trombones (and perhaps the trumpets, out of sight behind them) and Miles, of course, has his own mike.
The sound picture of the recording does not precisely match what we see in the photo, as the horns are heard to the left of the mix, as if behind the reed section. I suspect there was sufficient isolation in this setup to move the apparent image of the horns as desired. In most important respects, though, we see the same techniques as were used in the Sinatra recording: section by section pickup, with close mikes only for soloists or weaker instruments.
Additional evidence of the recording techniques of the time can be found in Harry Olson's "Music Physics and Engineering".(15) In chapter eight he diagrams typical setups for several kinds of recording sessions. His fig. 8.32, "arrangement of the instruments and microphones for recording a dance band or popular music orchestra" shows a big band arranged much as they would be in live performance, picked up with 6 mikes (including one for a vocal soloist) mixed to 3 channels. Olson comments about this arrangement, "Each microphone covers one instrument or a group of instruments with very intimate coupling between the microphone and the sound source. In the case of popular music a high order of definition is desirable. Because of the fast tempo of the music, the ratio of direct to reflected sound must be kept large or the reproduced music will be blurred." (16)
The mid-1950's to early 1960's have been called the golden age of stereo recording. The examples examined here support such a statement as, in each case, we can see the use of techniques that serve the characteristics of the music. It may seem self-evident that this is what sound engineering should be about, but other agendas are possible, especially if the engineer must please others who have a different understanding of the enterprise. A hint of this can be found in the same section of Harry Olson's book that I quoted above. He diagrams a setup for recording a symphony orchestra with no less than 15 microphones (fig. 8.29).(17) This is an astonishing development when compared to the two-mike setup that John Pfeiffer was using for orchestra sessions just a decade earlier. The consensus at RCA was that Pfeiffer was getting spectacular results. Why, then, the change?
An important clue is provided by Olson in his text accompanying the diagram. He states, "The use of multiple microphones makes it possible to obtain any desired balance of the various sections of the orchestra." Apparently, obtaining a reasonable pickup of the balance normally provided by the orchestra and conductor was not enough; the engineer must be able to drastically change that balance on demand. If the discussion were about film soundtrack recording, the need for such a capability would be obvious. Film sound serves the needs of the story and the picture, and so needs to be constantly flexible. But here we have the same idea being applied to straight orchestral recordings of the standard classical repertoire. What was going on?
1. A good example of this change from altered to full instrumentation can be heard on the CD "Louis Armstrong, Volume IV: Louis Armstrong and Earl Hines", Columbia CK 45142. On the first eight tunes, recorded from 1927 to mid 1928, the drummers (Tubby Hall or Zutty Singleton) can be heard playing only cymbals or wood blocks, when they play at all. Then, on track 9, "No (Papa No), recorded in December of 1928, Singleton is heard playing his full drum kit for the first time.
2. For examples of late 1920's dance music played by large dance orchestras, I suggest the listener turn to recordings of Jean Goldkette and His Orchestra or of Paul Whiteman and His Orchestra. A good selection of both groups can be found on the CD, "Bix Beiderbecke--Bix Lives!", RCA/Bluebird 6845-2-RB.
3. In his liner notes for "The Benny Goodman Story",(12) George T. Simon recounts how, in 1935, Goodman and his band replaced Guy Lombardo at the Roosevelt Hotel in New York City and were promptly fired for playing too loudly.
4. "Benny Goodman: The Famous 1938 Carnegie Hall Jazz Concert" is available on two CD's, Columbia Legacy C2K 65143 (issued 1999). The sound transfer, produced by Phil Schaap, is controversial: Schaap chose to use virtually no noise reduction on the old acetate disk sound, so there is lots of surface noise audible. In addition, he chose a rather bright-sounding equalization that certainly has a lot of presence, but emphasizes the noise and distortion of the original recording.
The dissatisfaction of many listeners with Sony's reissue inspired some attempts at using noise reduction and re-equalization to improve the sound of Schaap's transfer. (This was done in Europe, where copyright laws allow general reissue of older recordings.) Perhaps the best example of this was issued by the Jasmine label in 2006 (JASCD 656): engineer Bjorn Almstedt used the CEDAR noise reduction system and re-equalization to produce a warmer sound with a quiet background. Whether or not this is an improvement is a matter of taste.
7. Joel Tall, the CBS engineer who invented the tape splicing block, told of working with tape recorders made by the Brush company in his article, "Tall Tales", in Audio magazine, October 1978. The recorder, the Brush BK-401, recorded on fragile paper-backed tape. The stock model had a signal-to-noise ratio of about 35 dB and lots of distortion. By removing the power transformer from the machine and attaching it by a remote cable, Tall was able to improve the S/N ratio to about 55 dB. He tried applying negative feedback to lower the distortion, without much success. Even so, it proved useful to CBS for editing work during the late 1940's, and was even used to feed the radio network directly on occasion.
8. In Audio magazine, August 1993, Bert Whyte described how Helmut Kruger, a German radio technician, made stereo recordings of orchestra concerts in Berlin with a modified AEG Magnetophon, starting in 1943. Out of the hundreds of tapes he made, about five survived the war. Excerpts from these tapes were transferred to CD by Harmonia Mundi Acoustica in a limited edition, distributed to members of the Audio Engineering Society on the occasion of their 94th convention, held in Berlin.
10. Examples of such practices can be heard in Benny Goodman's recordings of that period for Capitol Records, available on "Benny Goodman: undercurrent blues", Capitol/Jazz 7243 8 32086 2 3. This CD contains most of the studio sessions of Goodman's "be-bop" band from 1947 through 1949.
I also recommend "Glenn Miller-The Lost Recordings", RCA Victor 09026-68320-2 (issued 1996). This two-CD set contains transcriptions for broadcast made by the American Band of the Allied Expeditionary Force (Miller's war-time service big band) in late 1944. The recordings were made in London in HMV's Abbey Road Studio No. 1 (still in use today for large-scale symphonic recordings). A conservative multi-mike approach was used with single microphones on brass, reeds, strings (a 20 piece string section!) and rhythm, along with an announcer/vocal mike. These are among the best big-band recordings Glenn Miller made, both technically and musically.
11. At first, record company executives were not certain that "high fidelity" would be desired by their customers. Tests carried out by broadcast engineers in the mid-1940's seemed to indicate that most listeners preferred playback of speech and musical materials through systems with restricted bandwidth as compared to systems with full bandwidth reproduction. If this were indeed true, there would be little point in mass-marketing high fidelity recordings and playback systems.
Harry F. Olson of RCA laboratories suspected that the studies indicating listener preference for low-fi were themselves flawed. He believed that as the playback system bandwidth was increased, the distortions inherent in the source material became more apparent and more irritating to the listeners. As the inventor of the ribbon element microphone and the designer of the professional ribbon element microphones that RCA subsequently marketed, Olson was uniquely placed to pursue such a question.
Olson's acoustic fidelity test
In 1947 he devised an ingenious all-acoustical experiment to test his thesis. He used a small room about the size of a typical domestic living room as his test site. A variable acoustic barrier was built across the room. This barrier contained vanes that could be opened or closed. In the open position, there was no restriction on transmission of sound to the other side of the room. In the closed position, a 5,000 cycle low-pass filter was approximated. (This was roughly the response of "good" consumer equipment of the time.) An acoustically transparent curtain was placed in front of the barrier, so that listeners could not see what transpired behind it. A six piece dance band playing at a moderate level (about 70 dB average) was on the other side. The vanes were opened or closed at about 30 second intervals. The listeners saw an indicator light change from "A" to "B" in synchronization with the vane changes and were asked which condition they preferred. The tests were repeated, using spoken voice as the sound source, all other conditions the same. The results were conclusive: the great majority of listeners preferred wide-range response under the conditions of the test.
The acoustic/electric test
Olson followed up this acoustical test with a second experiment. The same listening room was used, but this time, the musicians performed in an anechoic chamber where they were picked up in stereo by high quality microphones, with the signal delivered to the listening room by amplifiers and speakers developed by RCA's laboratory. This was the "A" condition. In the "B" condition, roll-off filters in the treble and bass were inserted in the reproduction chain to simulate the response of consumer equipment. Again, the results were conclusive: the great majority of listeners preferred wide-range response.
From today's vantage point, the outcome of Olson's experiments might seem intuitively obvious. But in the late 1940's, the answers to the questions he asked were not so obvious, given the small portion of the population that had ever heard high quality sound reproduction. Olson's experiments were important because RCA was, at that time, an enormously influential company. If RCA's executives had not supported the development of high fidelity recording and playback, the industry as a whole would not have moved as confidently in that direction.
(Olson's account of his tests, and a great deal more, can be found in his book, "Music, Physics and Engineering", second edition, Dover Books, NYC, 1967 (paperback), ISBN-486-21769-8. I recommend this book to all students of the art of recording.)
12. "The Benny Goodman Story" is available on CD, Capitol Jazz CDP 7243 8 33569 2 8, issued 1995. For comparison I recommend Goodman's recordings from 1936 through 1938 for RCA. These are available in several collections as of this writing. My source is a double-CD set on French RCA, "Jazz Tribune No.47, The Indispensable Benny Goodman, Vol.3/4 (1936-1937)", RCA 66470-2 07863.
13. The Bell Labs stereo recordings were a by-product of Bell's experiments in high fidelity recording in the early 1930's. The Bell engineers had formed a relationship with Leopold Stokowski, at that time conductor of the Philadelphia Orchestra, that allowed them to set up a recording laboratory in the basement of The Academy of Music, the orchestra's home base. Starting in 1931, they began to record rehearsals and concerts of the orchestra as test material.
Arthur C. Keller was Bell's resident expert on disk recording at that time. In the late 1920's he had come up with a two-channel disk recording system that used two grooves on the same disk and two cutter heads. His first recordings with the system were made of a theater orchestra in New York City. Those disks have been lost. However, in 1932 he set up the two-channel system in Philadelphia and made his first recordings there during a concert on March 12, 1932. Those recordings, along with some of the monophonic hi-fi recordings Bell made during the same period, were first issued on stereo LP disk in 1979. Engineer Ward Marston did the transfers from the original double-groove disks.
14. The best overview of Pfeiffer's work in early stereo is a two CD set, "The Age of Living Stereo: A Tribute to John Pfeiffer", RCA 09026-68524-2, issued 1996. Included are excerpts from the most important of his early experimental recordings from 1953 on, most of which have never been released in stereo before. (They sound magnificent, by the way.) Pfeiffer himself wrote a history of RCA's program, along with notes on the individual recordings included in the set. He died shortly afterwards, so the album was made into a memorial to him and his work. I highly recommend this set to anyone interested in the history of stereo recording.
copyright 2012, Robert Auld