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Knowledge in progress
Bolt, Beranek and Newman (BBN), the acoustic consultants led by Leo Beranek, engaged by the Lincoln Centre, carried out an impressive six year research program prior to the construction of Philharmonic Hall, including 60 halls in 20 nations, interviewing 20 well-known conductors and as many music critics. Before— (quote ”until now” ) there was reverberation time [ref]. Now—there was at least 18 more acoustical attributes [ref]. Among them, the attribute of Clarity was determined by the relative strength of direct sound [ref].
Intimacy was and has been controversial among acoustician. In Beranek’s writing, Intimacy seemed to emerge as a need for the oposite of the acoustics in a sports hall. Its metric, the initial time delay gap (ITDG) is a measure of proximity to walls or ceiling. In the special vocabulary of the broadcasting and recording industry, an intimate room has precence. It should not be confused with the sense of being close to to the music and the musicians. Surprisingly, Beranek concluded Intimacy was nearly 3 times as important as any other among the 18 attributes [ref].
In the list of attributes, there is a striking absence of spatial aspects, like source broadening or apparent source width (ASW), and sense of envelopment or being surrounded by sound. However, evidence of conciousness about spatial aspects is found: “At no time he feels that he is surrounded by sound”, on Leonard Bernstein’s (NYPhil chief conductor) first comment in the meeting with BBM after the opening, November 1962 [ref]. Bernstein describes it “like hearing music being written on a blackboard—a tableau effect”. Then, in July 1963, BBN recommends measures that would “give listeners a feeling of being immersed in sound, rather than being a spectator with the sound at a distance in front of him” [ref, item 7], the measure being removal of “the blue infill-panels” in the suspended ceiling, i.e. the reflector array seen in Figure 1. Bernstein and BBN used the synonyms surrounded and immersed for the kind of listening experience, a quality, they wanted. Enveloped is another synonym. They used different visual metaphors to describe a sense of ’frontal sound’, but basically they describe the same experience—how it made them being distant observers to the music being played up front, that it made music not interesting, not engaging, not involving. These descriptions, given half a century ago, are little different from descriptions by acousticians commonly expressed by acousticians today. It remains unexplained why the spatial aspects were not included in Beranek’s list of 18 attributes. Regarding the general conciousness about the significance of sonic envelopment in contrast to directional (frontal) sound, please refer to the memo to the musicians dated 1965-June-3 in the timeline below.
BBN initially “recommended a 2,400 seat "shoebox" design with narrowly spaced parallel sides (similar in shape to the acoustically acclaimed Symphony Hall, Boston). Lincoln Center officials initially agreed with the recommendation, and BBN provided a series of design specifications and recommendations. However, the New York Herald Tribune began a campaign to increase the seating capacity of the new hall and late in the design stage it was expanded to accommodate the critics' desires, invalidating much of BBN's acoustical work.
BBN engineers told Lincoln Center management the hall would sound different from their initial intent, but they could not predict what the changes would do [wikipedia]. “
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Timeline
Frequently appearing names below are: Leo Beranek of BBM, engaged by Lincoln Centre (LC) to advice Mr.Abramowitz (Architect), Mr.Schuman (LC), Mr. Bernstein (Music director, chief conductor, Nyphil); Members of the Acoustical Panel, Mr.Knudsen, Mr.Veneklasen, Mr.Keilholz, + one not mentioned; Mr.Mosely and Mr.Weissel, both directors at LC; From 1964 onward, Mr.Amyas Ames, director of the Philharmonic Society, in addition to presiding meetings of the Board, took a leading role and reported on progress in the acousic issues;
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1962-May-29
1962-Sept-71
1962-Sept-12
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Tuning week in the Philharmonic Hall
BBN suggest the procedure for the orchestra performing the acoustic stop-chord tests in rehearsals with audience, on 21st and 22nd September [ref]
NYPhil manager suggests Bernstein to introduce the tests, asking for silence, ”in the interest of time, and to spare the audience a speech by Mr. Beranek” [ref]
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1962-Sept-23
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Opening Night [YouTube] with Beethoven, Copland, Vaughan Williams, and Mahler [ref]
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1962-Sept-23++
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Mixed reviews. Several reporters panned the hall, while at least two conductors praised the acoustics [wikipedia] . Subsequently, as can be seen in the items below, a growing dissatisfaction rules, owner and tenant naturally avoid making the dissappointment an official one, hardly admitting the dissappointment to one another, hoping the criticism will fade away and thereby the whole problem. On the other hand, the musicians, with conductor Bernstein, and BBN with Beranek, immediately realize the problem with the acoustics of the hall is a real one. Not until the joint statement by LC and NYPhil 1964 August 13 did Bernstein go official about the problems, and then in an optimistic tone [NYTimes] .
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1962-Oct-18
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Board of Directors: ”There were several comments about acoustics; Mr.Keiser (presiding) stated that corrections were still being made, assembling data and opinions….Bernstein, Schuman (LC) and Beranek would listen on stage during rehearsals...and in the audience at performances (with a different conductor), in different parts of the hall, to study the question...Changes could be made this year if needed….or during the summer (1963)”
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1962-Nov-9
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Meeting between Bernstein and BBM, notes on Berstein’s comments as to acoustics in the hall, shortened from summary: Uninteresting sound in without sense of being surrounded by sound in the auditorium; Lack of strength in low pitched instruments between A (110Hz) and e’ (330Hz), however better in higher seats than in stalls; Domination of horns and woodwinds; Edgy high frequencies like they were amplified; Dependence on musicians on risers and/or in certain positions on stage is not acceptable; Dissappointed it’s impossible to speak to the musicians without strain, no better than in Carnegie [ref] ;
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1962-Dec-18
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BBN, recommended adjustments. The acoustics are not up to the standards of a hall of this importance; The hall opened in September with unsufficient projection of low-frequency sound; BBN supports Bernsteins descriptions (Nov-9, above); BBN have tested 1:10 scale models of the suspended ceiling (reflector array) and recommended to remove ”the blue in-fill panels” (grey fields in the ceiling plan, Figure 1, right). This would improve frequency balance* in reflections from the array, and open up for sound to reach the upper volume and return as reverberant sound, solving the issues of poor low-frequency projection, harsh high-frequency projection, and the lack of surround sound, as commented by Mr. Bernstein;
BBN had tested other suspects for possibly contributing to the low-frequency deficiency, such as the walls and upper ceiling of the hall. They used the measurements on the hung ceiling to derive that the panel materials do not absorb low-frequency sound, and from there concluded that walls and upper ceiling did not absorb sound (Comment: the reasoning here is not understandable, because wall panels with air backing are efficient low-frequencies absorbers, while freely hanging panels of the same materials are hardly absorbing at all); 240 downlights in the panels were suspected to absorb low-frequency sound, too, but were ruled out after scale model measurements;
As to Bernsteins appraisal of Philadelphia, BBN replied that Philharmonic Hall would never sound like P. or any other hall, but would after corrections of the present deficiencies be accepted by musicians and audiences as an excellent hall with qualities of its own. Further, BBN reminded that the excellent halls often referred to (Carnegie, Boston, Vienna, Amsterdam, Philadelphia), haven’t always been that perfect. They have all had deficiencies that needed to be corrected [ref];
*(BBN had proposed a reflector array with considerably larger panels than the ones actually built. The scale model tests proved that the proposed array had more than 10 dB better low-frequency response and less brilliance than the ones built [ref, curves a and b respectively], but it seems BBN refrained from proposing them to be replaced by their original design.)
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1963-Mar-28
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Executive Committee meeting minutes: Mr.Keiser reported on acoustics. Upon suggestion by Mr.Schuman (LC), four acousticians in addition to Mr.Beranek had been called in, i.e. the Acoustical Panel of experts. Mr.Weissel had made a report on the meeting with Mr.Abramowitz and the acousticians. [ref];
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1963-Apr-18
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Board of Directors minutes: Mr.Keiser reported, LC had called a press conference on Friday 12 April, regarding the report of the four acousticians (ref 28 March, above), who’s findings and recommendations had been quite unanimous and it was indicated that corrections would take place in two stages, the first between June 23rd and the end of July, and another one if necessary up to Labour Day (1st Monday of September). [ref];
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1963-June-27
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Executive Committee meeting minutes: Mr.Keiser reported that a few weeks ago the (NY Philharmonic) Society was shown plans by Knudsen and Veneklasen, acousticians who are advicing Mr.Abramowitz. Since the plans were very much different from the ones agreed upon by Knudsen and Veneklasen and Keilholz in April, LC was asked to have Mr.Keilholz come over from Europe for further consultation. After several meetings, Knudsen, Veneklasen and Keilholz reached an agreement as to what should be done. Changes will be according to these plans. There will be two stages, one between now and July 25th, and another beginning around Labour Day. The cost of these changes is estimated at about $400.000, and will be paid by LC. [ref];
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1963-Jul-26
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BBN letter to Lincoln Center and Mr.Abramowitz: ”We think the situation facing the LCBoard is now very serious”. After attending a concert in the hall on 24 July, after completion of the announced first stage of corrections, the result was jugded as less than satisfactory, in part because due consideration had not been given to viewpoints of all the members of the Acoustical Panel and BBN. BBN reminds that they made it very clear prior to opening night (i.e. 10 months ago) that as much as one year might be necessary to complete the tuning process. The only change made before the changes during the last month was the general 5 feet increased height of the panels above stage.
The corrections since 27 June included closing the vertical steps in the long section of the panel array (Fig 1, left). A steeper rise over the stage has strengthened the sound from the rearmost instruments, and worsened the balance between instruments. BBN maintain the only solution is to change the angle and average height of the panels above stage, as recommended 18 December. The present great height of the suspended ceiling (panels) above the audience has seriously decreased the acoustical Intimacy.(This means that the first reflection was intended to come from the suspended ceiling, a vertical early reflection that would increase the sense of frontal sound, at the cost of spatial aspects). [ref];
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1963-Dec-19
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Executive Committee minutes: Mr.Weissel reported that Lincoln Center had authorized Mr.Keilholz to submit sketches and plans for the changes and improvements he had suggested in his memorandum. After a study of the plans, LC will decide wether to put them into effect. In Mr.Keilholz opinion, expressed to the officers of LC, with his suggested changes Philharmonic Hall could be a fine hall acoustically. [ref];
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1964-Apr-16
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Executive Committee minutes: Mr.Ames reported that he and Management had met with representatives of LC for further discussions of the acoustical problems of the hall (Note that this is the first time the word ”problems” appears in the minutes). Mr.Ames pointed out that the man who appared best qualified to improved the situation is Mr.Keilholz, who also seemed to have the confidence of Bernstein, Szell and Schuman. At the meeting, Mr.Ames continued, LC and the Philharmonic decided to invite Mr.Keilholz to come to New York City as soon as possible, and to share Mr.Keilholz expences and fee for this one trip on a 50-50 basis. He pointed out that such expense could be properly attributable to the ”move to Lincoln Centre” for which funds have been set aside. The meeting approved the invitation and the sharing of costs. [ref];
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1964-Nov-19
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Mr. Ames said that in addition to various letters received from outstanding musicians, a letter had been received from Mr.Szell complimenting the (NYPhil) Society on the outstanding improvement of the acoustical qualities of the hall. He added that Mr.Steinberg (ref. missing), too, had acknowledged the improvement of the acoustical qualities but that he had ideas for possible improvement. It was also reported by William Weissel that the garage service was improved and that further improvements were under consideration. [ref];
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1965-May-6
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Mr.Ames reported on Philharmonic Hall by stating that last year’s changes made upon Mr.Keilholz’s recommendations had greatly improved the acoustical qualities of the hall and the sniping of the press and the adverse talk by the public in general had stopped.
Three steps were originallly envisaged to improve the acoustical qualities; one of which was taken in the summer of 1963, the second in the summer of 1964, by enclosing the stage by wooden walls and enclosing the gaps between the clouds. The third step as originally suggested by Mr.Keilholz would include the erecting of wooden walls and removal of the sound absorbing chairs in the auditorium.
During the Promenades the chairs in the orchestra area are removed and replaced by tables and non-upholstered chairs. Experience has shown that acoustical qualities during the Promenades period were greatly improved.
After thorough investigation and study of the problem it has now been recommended to remove the present chairs and to replace them by chairs only partly covered by upholstery. This wil result in not only in removing the source of sound absorption, but since these chairs will occupy less space would permit adding 200-280 seats...the additional revenue would be split between NYPhil and LC.
The financing of the above...through monies borrowed by NYPhil from LC...repaid within a year and a half.
The chairman added the work would be done in August. He asked Board members to keep the information confidential [ref];
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1965-June-3
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A memorandum from Mr.Ames to the members of the orchestra, informing about the planned corrections. Last year, when the Philharmonic and Lincoln Center joined ogether to seek counsel on the acoustics of Philharmonic Hall, we were told by our advisor Heinrich Keilholz that three changes would be necessary:
1) to enclose the stage in a ”shell” of wood,
2) to change the reflecting quality of the hall,
3) to remove excess overstuffing and carpeting from the Orchestra section (stalls/main floor). It was decided to proceed step by step, and only 1) was completed last year. After a season of testing, this new stage has been judged a success. ..the other two changes scheduled for August so that the hall will be ready for the fall season.
Justification of 2): Sound reflecting panels aof natural wood will be placed along the side wall of the auditorium, their curved shape and the angle of their placement to reflect the sound back, down and out over the audience, much as a hand placed behind the ear directs sound into it. Such reflectors are the practical answer to the problem posed by modern architectural smoothness; acoustically they are the modern substitutes for balcony supporte, boxes statue niches, etc., so commen to the older halls. They are designed to give the audience a sense of being enveloped in the musical sound.
These reflecting panels will also be extended onto the walls of the stage, since this will increase the ability of performers and conductors to hear themselves and each other, and this has been a very important consideration in our decision to take these further steps in developing the hall.
In addition, the actual walls of the audience area of the hall will be encased in wood. This is an extension of the highly successful wood ”shell” around the stage. Sound reflected off the natural and variegated surface of wood has a quality more pleasing than if it has been reflected off the hard, glassy surface of painted concrete. Wood is the friend of musical sound
(The widespread notion that wood by nature is the preferable material whereever ther’s music is questioned by the fact that it has not been confirmed by blindfold listening experiments. On the contrary, wood glued to concrete does not change the reflection properties measurably. If not very thick, heavy and with sealed joints, wooden walls and ceiling can be detrimental to concert hall acoustics. Alte Gewandhaus was historically the ultimate disaster case in this regard. With an inner shell intended to act like the vibrating body of a violin, acoustical energy was converted into heat and dissipated from the volume of the hall).
Justification of 3): Musicians know that chamber music sound s best in a room without rugs. The same principle...proved to be effective ...when seats and carpeting are removed from the Orchestra (stalls/main floor) for the Promenades.
The carpets and the overstuffing in the Orchestra seats have the the effect of making one whole side of the ”acoustical cube” sound absorbent — a partial muffler — so that sound feels directional rather than enveloping. [ref];
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1966-Nov-15
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Mr.Ames stated that certain corrective measures still had to be taken since not all corrective measures suggested by Mr.Keilholz in previous years had been executed. He continued that the fan room as well as the dishwasher in the café(!) will have to be made sound proof,..., and the clouds over the stage in the auditorium ougth to be replaced by a ceiling.
Mr.Ames contiued...although acoustics on stage had improved since the changes made two years ago, there are still a number of places where it is difficult for the musicians to hear themselves or others (musicians or conductor. Questionnaires had been given to all orchestra member asking for for comments on acoustics, now been turned over to Mr.Keilholz for study. Recommendations to replace clouds in auditorium and over stage with ceiling would be made to LC’s Board.
A study by Mr.Keilholz and Mr.Abramowitz as to what to be done and in what manner would be recommende to the Board for approval. [ref];
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1967-April-19
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Mr.Ames reported that acoustics in the hall will have to be improved further though great improvements had been achieved by the work done in 1965. Mr.Abramowitz and Mr.Keilholz have worked out a plan and are in full agreement as to what has to be done.
LC had decided not to make the changes in 1967 but in 1968.
….a model had been made, showing the proposed new ceiling from the back of the hall continuing to and including the stage area. This ceiling together with the existing side walls would create an acoustical shell-like effect, according to Mr.Keilholz, who had stated that conditions on stage would be definetely improved and would most likely improve the present condition in the hall. [ref];
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1967-Oct-26
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Mr.Ames questioned Mr.Keilholz—why not correct only the ceiling over stage and leave the ceiling over the auditorium as it is Mr.Keilholz replied that while this might be difficult for a layman to understand, the stage and auditorium is one unit and cannot be separated, and the entire ceiling has as much to do with the stage as the auditorium, and for this reason it has been recommended to have a totally closed ceiling.
Not only for acoustical reasons, but for psycological ones, since a musician who looks outards not seeing a closed ceiling would feel, rightly or wrongly, that the acoustics are not to his satisfaction.
Mr.Keilholz continued that at the present acoustics in the auditorium are satisfactory, whereas not on stage.
Mr.Ames asked if putting in new chairss could be left out to save money, but Keilholz replied recommending to do all improvements, ceiling and chairs, or nothing, because piecmal improvements would create disturbance and the things left out would be pointed out as reasons why no improvements has been achieved….only full and complete changes will bring the desired effect, and must all be done at one time like a drummer hitting a drum. ...by not correcting everything there will always linger the ide that it has not been improved sufficientlyd, since corrections still have to be made.
Mr.Ames stated the Society has been told time and again by Mr.Bernstein, Mr.Szell, by artists and orch. Members that there still exists acoustical problems in the hall. Mr.Ames continued that great and important changes had been made by the corrections Mr.Keilholz had executed so far. However, there are still problems over the stage strongly felt by the orchestra.
Whenever the orchestra would play in the shell in the parks, members would say they hear themselves well, whereas lacking this experience on the stage at Philharmonic Hall. Mr.Keilholz replied he had never been happy with just the corrections over the stage, and always avocated a new, closed ceiling over stage and auditorium.
Mr.Keilholz stated further that acoustical demands of halls nowadays become more severe every year, and what seems acceptable today will not be acceptable two years hence...Closing of the total ceiling would add reverberation time (today a fraction over 2, but hoping for 2.16) and brilliance to the sound (compare with comments of too much brilliance, e.g. edgy high frequency like they were amplified, as commented by Mr.Bernstein 9-Nov-62 ). He added that the low frequency had always presented a problem in the hall, but by correcting the ceiling as proposed, this would be improved.
After Mr.Abromowitz and Mr.Keilholz left, a suggestion to lend LC 500.000$ interest free towards financing the job, including new ceiling and chairs (in upper levels), to be repaid by LC over 5 years, was unanimously approved.
[ref];
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1968-Jan-10
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Mr.Ames stated that there still persists a great acousical problem in the stage area which makes it extremely difficult to hear themselves, each others, or directions given by the conductor, who in turn has difficulty in hearing the various instruments of the orchestra. These complaints had not only come from orchestra members, but again and again from conductors such as Mr.Szell, Steinberg, Bernstein and others.
Mr.Ames continued that Mr.Keilholz from the beginning had made it absolutely clear that the acoustical problems of Philharmonic Hall can only be solved in making, in addition to the corrections so far executed, corrections of the ceiling over stage and autitorium. Mr.Keilholz and Mr.Abramowitz had worked out plans and were in full agreement as to what has to be done.
According to Mr.Keilholz the acoustics in the auditorium is now fine, but the proposed changes would improve acoustics in the auditorium another 15%, and would correct the unfortunate acoustical situation on stage.
LC had previously thought of having the corrections made in the summer of 1968, but it now had become clear that this would not be possible. The summer of 1969 is now the period, some 12-13 weeks, the period when these corrections would be made. LC in lack of funds, the NYPhil Board unanimously agreed to offer LC help to finance the corrections.
[ref];
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1969-Sep-10
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THE NEW PHILHARMONIC HALL, a statement by Mr.Ames, President NY Philharmonic:
Four years ago (1965), after preliminary adjustments in the hall had not proven successful, the NYPhil Society undertook to correct the acoustics of the hall….”it has taken time...It means so much to us to have a fine hall, that I woul like to retell the story of what has been done and why.
A key figure in the story is Heinrich Keilholz, a West German with a genious for designing and improving concert halls. He was strongly recommended to us by (conductor) George Szell, who valued him as his adviser on Severance Hall in Cleveland.(mor recently he designed Blossom Music Center, Ohio and Alice Tully Hall at LC).
Keilholz is man with a sensitive ear for music, who talks the language of musicians, a man who places more emphasis on the human ear than on electrical measuring devices, a man who bases his counsel on what has worked for centuries. After studying the hall in 1965, he prescribed certain changes. We have been making these changes one by one and have found—as he told us in the beginning—that, as the parts of the plan was interrelated it was necessary to complete them all to make the hall right.
What he told us, in effect, was that the old-fashoned ballroom with its hard wood floor, curved wooden boxes and balconies, its gilt chairs and crystal chandiliers, has always been one of the finest places in which to hear music.
The first recommendations was to correct the over-smooth surfaces by superimposing curved reflecting surfaces, ...to the back of the stage, ...made the side walls curve in sections. Most important, ...in wood, since wood …. Is friendly to music.
The next change was to reduce the amount of fabric in the hall, the carpeting and overstuffed chairs muffled the sound.
The final step taken was to correct the ceiling,... the difficulty was caused by the shape of the ceiling, which curved sharply up towards the back of the stage and again up over the audience so that there was only a minimal area to reflect sound down to the players. The clouds which originally was meant to do this had turned out to be mor mufflers than reflectors.
The solution (to the latter) was to install what is equivalent of a shell over the stage and extend it in steps over the audience, so that all areas of the ceiling are parallell to the stage floor, giving to the music a maximum reflecting surface, equivalent to the ceiling of a ballroom. This ceiling is made in unusually thick sections of wood in order to make it most effective as a sound reflector.
We were advised that the best loved concert halls use warm and light colors, and that this helps to build rapport between artist and audience. As we travelled through Israel and Europe last year, playing in 22 concert halls, we found that Bernstain and members of the orchestra repeatedly expressed such a preference.
All of the recommendations made by Heinrich Keilholz in 1965 have now been carried out. The cost of this final work was $1.300.000, exclusive of regular maintenance expenses by LC.
The work on the hall had to be done between June 15th and September 15th…, (despite difficulties) the work was finished on time and within budget.
The new Philharmonic Hall is now finished.
[ref];
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1969-Oct-1
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Hannover, October 1st, 1969. Letter from Mr.Keilholz to NY Philharmonic Hall: ”You, Mr.Ames, and myself know very well that complaints should not be taken seriously which could perhaps be advanced by part of a orchestra-member or by the public.
Now we have to make corrections on the inside of the stage-room (corrections at the raises and placing of the orchestra).”
Last part of the letter is about ”...request to approve my latest supplement charges.”
[ref];
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1969-Dec-3
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Executive Committee Meeting Minutes, item 5. Acoustics. Certain members of the orchestra present stated that they still didn’t hear themselves and other players well on stage, a fact which was especially stressed by cellists and double bass players.
It was pointed out that different floor on the stage (different wood) would be helpful, though they were told that it does not make a difference to the listener in the auditorium, they felt more comfortable on the stage when playing on platforms.
[ref];
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1970-2017
(wikipedia)
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Management made several attempts to remedy the induced acoustical problems, with little success, leading to a substantial 1970s renovation designed by acoustician Cyril Harris in conjunction with project architect Philip Johnson.
It included demolishing the hall's interior, selling its pipe organ to California's Crystal Cathedral, and rebuilding a new auditorium within the outer framework and facade. While initial reaction to the improvements was favorable and some advocates remained steadfast,[11] overall feelings about the new hall's sound soured and acoustics there continued to be problematic.
The hall underwent renovations in 1976 to address acoustical problems that had existed since it opened. Another smaller renovation attempted to address unresolved problems in 1992. Both projects achieved limited success.[4]
In May 2004, the orchestra announced that the building would undergo renovations in 2009,[5] but in June 2006, The New York Times reported that the construction had been delayed until the summer of 2010.[6]
By 2012, it became clear that construction would not start before 2017. The shell of the building was to be left intact and work was to focus on improving the hall's acoustics, modernizing patron amenities and reconfiguring the auditorium.
On November 13, 2014, Lincoln Center officials announced their intention to remove Avery Fisher's name from the Hall and sell naming rights to the highest bidder as part of a $500 million fund-raising campaign for its refurbishment.[7] Lincoln Center chairwoman Katherine Farley said, "It will be an opportunity for a major name on a great New York jewel." Fisher's three children agreed to the deal for $15 million.[1]
On October 3, 2017, it was announced that existing renovation plans for the Hall had been scrapped.[8]
Source: [Wikipedia article on Geffen Hall];
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A simulation study in 3D models of Geffen Hall
Can the perceived changes reported by audience and musicians’ during Mostly Mozart be seen in simulations in 3D models?
Could the suggested changes in the upper balcony provide acoustics similar to what is found in world top-3 halls?
In 2018, in an R&D study, Akutek and Brekke & Strand explored acoustical effects of modifications in a 3D model of Geffen Hall.
Among the conclusions from the study was:
· Early Decay Time (EDT) turned out to be the simulated parameter that best describes the perceived improvement during Mostly Mozart
· Significant improvements can be achieved with stepwise modifications to the hall, made during summer closing period
The following modifications are judged to justify loss of seats and other costs, with minimal downtime:
· Moving from regular stage to Thrust Stage, would justify loss of 200 seats
· Remove and put to store all seats on all 3rd tiers, would justify loss of another 386 seats
· Increase surface weight of plywood lining, all walls, would justify construction cost
After these modifications in the 3D models, simulated parameter values are in the range of those simulated in models of the top-3 halls in Boston, Amsterdam and Vienna. The new seat count would be 2156, i.e. a loss of 586 seats, compared to an average of 2100 seats in the top-3 halls.
Regarding the suggested «Knocking out the upper balcony» (Vulture 2017): Demolition of entire 3rd tiers (sides and rear) can bring even more warmth and bass response, but the following should be carefully considered: Downtime; Cost; It is a non-reversible modification; The 3rd tiers without chairs could be an option for extra capacity and revenue in events with standing audience.
After each incremental modification, measurements and a concert season or two would provide a basis for decision about another modification.
In particular, since knocking out a balcony has such big consequences but uncertain benefit, this modification should not be a starting point, but more like a last option.
The full presentation of the study is found here: https://www.akutek.info/Presentations/MS_Geffen_Hall_pres.pdf .
A copy of the presentation was sent to Lincoln Center in 2018.
Illustrations of the 3D models
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