Microsoft Word - Tyler_Dare_Physics 498 Report.doc

Multipurpose Auditorium

Tyler Dare

Physics 498 POM

May 13, 2005

1. Purpose

A major problem when constructing an auditorium is deciding what its primary

function must be. The acoustics for an orchestra hall vary greatly from those for a

proscenium theatre or a large lecture hall. However, many institutions, such as high

schools and small colleges, only have space and money for once of these arrangements.

As a result, the good acoustics for some arrangements is often sacrificed. However,

auditoriums can be designed to provide good acoustics for many different types of

performances. To illustrate this, the multipurpose auditorium was designed. The goal

was to design an auditorium that would have excellent acoustics for a variety of purposes,

specifically orchestra, drama, and lectures.

2. Theoretical Background

The acoustics of a room is usually a subjective quality. Concertgoers describe a

hall as “live” or “dead” and talk about the “shimmer” of the strings. Theatre patrons are

primarily concerned with how well they can understand the speakers. There are a few

quantitative measures of the acoustics of a room.

2.1 Reverberation Time

The most important of these parameters is reverberation time. Reverberation time

is defined as the time it takes for an impulse of sound in a room to decay 60 dB, or one

millionth of the original level. This value is affected by most everything in the room,

including room volume, absorption of room materials, diffusion from surfaces, and room

temperature and pressure. An estimate of reverberation time is given by the Sabine

Equation:

⎟

⎠

⎞

⎜

⎝

⎛

T 049.0,

where T is the reverberation time, V is the room volume in ft

, and A is the effective area

of absorption, given by

∑

aSA

where S is the area in ft

and a is the absorption coefficient of all N surfaces in the room.

This equation assumes that the room is not too oddly shaped (e.g., a tunnel) so that the

sound energy can spread out easily throughout the room. The equation also does not take

into account the effects of room atmosphere on sound. This equation is purely empirical,

using data collected in the late 1800s. The measurements of reverberation time were

taken at 512 Hz, which limits the description of the reverberation of the room to this

single frequency.

A more accurate estimate of reverberation time is found by using ray tracing with

acoustics modeling software. A model of the room is created, giving each surface its

absorption and diffusivity coefficients, and sound sources are placed in the room. The

ray tracing technique involves following rays shot out from the source in different

directions. When a ray encounters a surface, its intensity is reduced according to the

absorption coefficients, and it goes in a new direction according to the diffusivity of the

surface. If this process is done with thousands of waves at each octave band, an accurate

estimate of the sound levels at each location in the room can be calculated, based on how

many rays of each intensity reach a particular audience area. The most common measure

of reverberation time for these programs is T-30, which is calculated from the slope of a

best fit curve for the sound levels and times as the sound decays from -5 to -35 dB. This

tends to be more accurate that the Sabine equation because it takes into account not only

the absorption of the surfaces, but also the diffusivity, the specific shape of the room, and

the locations of the sources and audience. Also, the reverberation time can be calculated

at many different octave bands, which is a more telling measure of the sound of the room.

2.2 Speech Intelligibility

While the reverberation time is the most important factor in the acoustics of a

room, speech intelligibility is also important, especially in dramas and lectures. One

useful way of measuring speech intelligibility is by using D-50.

D-50 =

∫

∞

050.0

)(

dttp

, where p is the pressure level and t is time in seconds

This is a measure of the percent of the total sound energy arriving before 50 ms after the

initial pulse of sound. The idea is that sound energy heard by the audience before 50 ms

is beneficial to the understanding of speech in that it increases the volume of the words

spoken. On the other hand, sound that comes after 50 ms is detrimental to speech

comprehension, because it tends to muddy the sound and make it less clear. A high D-50

indicates that the audience will easily be able to understand speech. This parameter must

be found using ray tracing software, as there is no simple equation to estimate this value

like the Sabine equation.

2.3 Sound Coverage

A final desirable quality for an auditorium is even coverage of sound. There

should be no seats in the audience where the sound level is significantly lower or higher

than the rest of the audience. Problems can be predicted and adjusted using ray tracing

software before the auditorium is built. Sound pressure levels can be mapped over the

audience area to see if there are any spots with more than a few dB difference. These

mappings typically output specific sound pressure levels, but these are not as important as

the even coverage, as sound amplification can always be used.

3. Desired Qualities

With the parameters defined, it is necessary to determine what the best acoustic

measurements are. While the optimal acoustic parameters will vary depending on the

preferences of the listener, some spaces have been judged consistently as among the best

in the world.

3.1 Boston Symphony Hall

Symphony Hall in Boston is usually considered the best orchestra hall

acoustically in the United States. It was built in 1900 with acoustical consulting by

Wallace Sabine, who come up with the Sabine equation a few years earlier. Soloists

enjoy the intimacy of the response of the hall, and music critics say the music heard is

clean and clear. Boston Symphony Hall was the model for the concert hall setup of the

multipurpose auditorium. Its relatively simple, rectangular shape also makes adjustments

easier to make, which will be important in the multipurpose auditorium. The goal of the

orchestral setup of the multipurpose auditorium was to match the acoustics of Boston

Symphony Hall by mimicking its dimensions closely.

Boston Symphony Hall has a reverberation time of 1.8 seconds when fully

occupied. This measurement is an average of ones at 500 and 1000 Hz. While this is

slightly shorter than average halls of the same size, many critics think that this is what

gives the hall its superior quality over even the best concert halls, such as the Grosser

Musikvereinssaal in Vienna. It contains 2631 seats, with 1486 on the main level and 598

and 547 on the two balconies. For the multipurpose auditorium, the top balcony and the

side portions of the lower balcony were eliminated. Most of the materials from the

Boston hall were used, including the plaster walls and wood floors.

3.2 Royal Shakespeare Theatre

With the primary setup for the multipurpose auditorium established, adjustments

must be made to make the space appropriate for other uses. For drama, a good model for

suitable acoustics is the Royal Shakespeare Theatre in Stratford-upon-Avon. It would be

difficult to mimic the shape of this theatre by modifying the orchestral setup of the

multipurpose auditorium, because this theatre is fan shaped instead of rectangular.

However, the acoustical measurements can be used as a guide for what the acoustics of

the drama setup of the multipurpose auditorium should be. Royal Shakespeare Theatre

has a reverberation time of 1.0 seconds and a capacity of 1459 over three levels. The

portion of early energy from a centrally located source is about 72% on average and

ranges from 60 to 80%, depending on the location of the measurement in the theatre. The

dimensions of the fly space were used as a model for the multipurpose auditorium.

3.3 Classroom Acoustics

For the lecture hall setup of the multipurpose auditorium, the drama setup can be

altered to include a chalkboard, podium, and other teaching aids. However, the acoustics

must also change. The American National Standards Institute recommends a maximum

reverberation time of 0.7 seconds for classrooms between 10,000 and 20,000 ft

. It also

recommends in Standard S12.60 for Classroom Acoustics that the background noise in a

classroom should not exceed 35 dB. While the volume of the multipurpose auditorium

will greatly exceed 20,000 ft

, 0.7 seconds is a good standard for good speech

intelligibility in a lecture hall setup. The multipurpose auditorium also will not have

much background noise, as the background noise requirements for a quality orchestral

performance space will be below 35 dB. A performance space will usually have a

remotely located HVAC system, which is the main source of background noise for

classrooms.

4. Auditorium Design

After the criteria for all three setups of the multipurpose auditorium were

established, design began. A number of initial sketches were made, primarily concerning

the method of reducing the volume of the space so as to decrease reverberation time.

Next, the design was put into AutoCAD 2005 so as to have a three dimensional

representation of the auditorium. The exact dimensions of everything in the auditorium

were finalized and entered into CATT-Acoustic, an acoustics modeling program that uses

the ray tracing technique.

4.1 Initial Design

The most critical problem with varying the acoustics of the multipurpose

auditorium was determining how to change the reverberation time of the room. Many

modern auditoria use absorptive hanging curtains in the audience area to fine-tune this

parameter, but a large volume change is needed to alter the reverberation time by more

than a few tenths of a second. The solution was to install a retractable ceiling above the

audience. This ceiling would cut off the balcony as well as about a third of the volume of

the audience area, significantly reducing the volume of the room. The bottom of the

ceiling would be made of absorptive ceiling panels, which would prevent too many

detrimental reflections off of the ceiling. Since the ceiling would cut off the balcony, it

would reduce the capacity of the house, but since the majority of the seats are on the main

floor this would not make too much of a difference.

The second major problem was designing an orchestra shell which would cut off

the fly space and its absorptive curtains. The goal was to have as much of the sound

energy as possible be directed towards the audience. The solution was to make the sound

shell span the width of the stage and reach to the top of the stage opening so as to

minimize the amount of energy lost into the fly space. The elliptical shape prevents the

sound from being focused at one point in the audience, a common problem with parabolic

and circular reflectors, and also allows the shell to reduce the depth of the stage to the

minimum necessary for an orchestra performance. The shell was designed to be made of

a highly reflective material such as sealed plywood.

The final problem was finding a way to further reduce the volume of the room to

reduce the reverberation time for the lecture setup. This was solved by having a movable

heavy curtain between the two sections of the main floor. A curtain was used because it

would not reflect sound back onto the audience, as this would inhibit speech

intelligibility. This will cut down the audience area substantially, but even the largest

lectures rarely exceed 500 students, which will be the approximate capacity of this setup.

4.2 AutoCAD Modeling

The initial model of the multipurpose auditorium was made in AutoCAD 2005.

First, the major dimensions of Boston Symphony Hall were used to form a basic outline

of the auditorium. The balconies and stage were left out. The stage and fly space were

made by adjusting the dimensions of those of the Royal Shakespeare Theatre to make

them fit with the walls already in place. With all of the permanent walls in place, the

movable ceiling and curtain were added on different layers so they could be turned on

and off to see the different setups. Finally, the sound shell was added so the elliptical

shape met with the walls and opening of the stage.

4.3 CATT-Acoustic Modeling

After a demo version of CATT-Acoustic was obtained, the next step was to

transfer the AutoCAD model to the acoustic software. In the full version of CATT-

Acoustic there is a module that will convert AutoCAD files to the CATT-Acoustic

format, but unfortunately this is not part of the demo version, so the model of the

multipurpose auditorium had to be manually put into the program. To do this, all of the

vertices of all of the planes that make up the room were given coordinates taken from the

AutoCAD model. Then, the planes were defined by connecting the vertices. Absorption

coefficients and colors were assigned to each surface to facilitate ray tracing and three-

dimensional modeling of the auditorium. The absorption coefficients of each surface

were defined in percents across six octaves, from 125 Hz to 4 kHz. For instance,

audience areas were modeled as fully occupied, upholstered seats, with <60 74 88 96 93

85> as the percent of absorption for the <125 250 500 1k 2k 4k> Hz frequencies. After

all of the surfaces were added, initial computations were made using the software.

4.4 Initial Results and Troubleshooting

There were a few problems with the first design of the multipurpose auditorium.

First of all, the reverberation times for all setups were too long. The reverberation time

was shortened to an acceptable level for the orchestra setup by adding a curtain on the

back wall. This absorbs some sound without eliminating any of the important direct

sound or early reflections. A balcony was also added, which reduced the reverberation

time while increasing the capacity of the house. The reverberation time of the lecture

setup was also improved somewhat, but it was still too long. This problem was solved

with the realization that there were no curtains hanging in the fly space. Three curtains

were added in the fly space, and their added absorption reduced the reverberation time to

the desired value range, while not affecting that of the orchestra setup because the

orchestra shell cut off the fly space. Small hanging curtains near the side walls were

added to further reduce the reverberation time if needed in any setup. A large problem

occurred with the lecture setup. When the hanging curtain was added in the center of the

auditorium, the reverberation time increased instead of decreasing. This problem was

eventually solved by adding transparency coefficients to the curtain. This allowed some

of the sound energy to pass through the curtain to the unused portion of the auditorium,

reducing the total sound energy in the lecture portion and reducing the reverberation time

to an appropriate length.

5. Results

The results of the multipurpose auditorium were calculated using the CATT-

Acoustic software. The numbers were compared to the two model performance spaces as

well as the ANSI standard.

The audience capacity was calculated by dividing the audience area by the

average area per seat, usually taken to be about 0.5 m

, or 5.38 ft

. The area of the two

front audience areas is 1200 ft

each, of the two back areas 1500 ft

each, and of the

balcony area 1950 ft

. For the orchestra setup, which uses all of these areas, this gives a

capacity of

1366

/38.5

19502*15002*1200

222

seatft

ftftft

Capacity seats

Similarly, the capacity of the drama setup is 1004 seats, and the lecture setup can hold up

to 446 people. These numbers are in the range of the desired capacity at the beginning of

the project.

5.1 Orchestra Setup and Boston Symphony Hall

The only acoustical statistic that could be found for Boston Symphony Hall was

reverberation time, 1.8 seconds. This was found by averaging the reverberation times at

500 and 1000 Hz. If this is done for the multipurpose auditorium, the result is 2.0

seconds, slightly longer, but still in the range of a premiere concert venue. Since the

majority of the dimensions of the multipurpose auditorium were taken from Boston

Symphony Hall, the two spaces should sound approximately the same. The multipurpose

auditorium holds less people than Boston Symphony Hall, with 1366 seats in the

multipurpose auditorium compared to 2084 for the first two levels for the Boston hall.

This is because of the removal of the side balconies from the Boston design and the

widening of the aisles. If this is too few seats for the intended owners, a second balcony

could be added above the existing one in the plan, adding about 300-400 extra seats. The

orchestra setup of the multipurpose auditorium is a good replica of Boston Symphony

Hall, with similar acoustic properties.

5.2 Drama Setup and Royal Shakespeare Theatre

While the drama setup is merely a modification of the orchestra setup and quite a

different shape from most drama spaces, their acoustical properties are comparable.

Royal Shakespeare Theatre in Stratford-on-Avon has a reverberation time of 1.0 seconds.

The drama setup of the multipurpose auditorium also has a reverberation time of 1.0

seconds. The Royal Shakespeare Theatre has about 72% early sound energy on average.

CATT-Acoustic estimates the D-50 of the multipurpose auditorium to be about 95%.

This is much higher, which might indicate that the lecture setup will sound somewhat

dryer than the Royal Shakespeare Theatre. This could be altered by removing some of

the absorptive material in the audience area, but this would increase the reverberation

time also. A model would have to be constructed to determine the extent of the early

energy fraction problem. A mapping of sound pressure levels over the audience area

shows that there is even coverage of sound across all of the seats. The 1004 seats are

slightly fewer than the 1459 for the theatre in Stratford, but should be ample for the needs

of the intended owners.

5.3 Lecture Setup and ANSI Standard S12.60

The lecture setup as similar acoustic properties to the drama setup of the

multipurpose auditorium. It has the same even coverage of sound as the drama setup, and

the added curtain lowers the reverberation time to about 0.7 seconds. This is within the

maximum reverberation time defined by ANSI Standard S12.60, especially considering

the volume and capacity of the hall. The D-50 of the lecture setup is about 98%, which

still might be too dry for a lecture, but this can again be altered somewhat. The capacity

of 446 should be enough for almost all lectures, and the students will be able to

understand the speech better than in most other lecture halls.

5.4 Errors with CATT-Acoustic Demo

There are a few problems that are the result of using the demo version of CATT-

Acoustic. First of all, there was no way to convert the AutoCAD model to the CATT-

Acoustic format. This did not affect the prediction of acoustic properties. A large

problem is that the demo version limits the number of rays used in the ray tracing

technique to 1000 per octave. This limits the accuracy of all of the measurements

because fewer rays mean odd reflections and slight disturbances in a few waves can

change the measurements drastically. For a room about the size of the multipurpose

auditorium, about 10 to 100 times this number of rays should be used at each octave for

an accurate prediction. This limitation might have added to the early sound energy

fraction discrepancy.

6. Conclusions

The multipurpose auditorium was intended for use in a small college or high

school with limited space and money, but a need for many different performance types.

To facilitate this, the auditorium was designed so it could be altered for orchestra, drama,

and lecture functions. The three setups were modeled after premiere performance

venues, including the Royal Shakespeare Theatre and Boston Symphony Hall. The hall

was designed in AutoCAD 2005 and CATT-Acoustic software. The results, found using

CATT-Acoustic, are quite impressive. The orchestra setup has acoustic properties

closely resembling this of Boston Symphony Hall. The drama setup has properties close

to the Royal Shakespeare Theatre, with discrepancies in the percent of early energy. The

lecture setup meets ANSI Standard S12.60 with a low reverberation time and even

coverage of sound. Limitations in the demo version of CATT-Acoustic may have caused

errors in some calculations. In all, this was a worthwhile project with many challenges

but a very rewarding result.

7. References

Barron, Michael. Auditorium Acoustics and Architectural Design

London: Routledge, 1998.

Beranek, Leo L. Music, Acoustics & Architecture

. New York: John

Wiley & Sons, Inc., 1962.

Dalenbäck, Bengt-Inge. CATT-Acoustic v8.0c (build 7.01)

(Limited demo/evaluation

version). 2005.

Associated Productions of Texas Communications. “Absorption Coefficients of Building

Materials and Finishes”. http://www.aptcommunications.com/abcoef.htm

AutoCAD 2005 Screenshots

Model in AutoCAD with permanent walls (pink), movable ceiling (yellow), movable

curtain (orange), and orchestra shell (blue)

CATT-Acoustic Screenshots

Labeled vertices defining planes

Output of reverberation time and other parameters across octave bands

CATT-Acoustic Screenshots

SPL and D-50 mappings at 1 kHz for drama setup

SPL and D-50 mappings at 1 kHz for lecture setup

3-D rendering of orchestra setup

CATT-Acoustic Screenshots

3-D rendering of orchestra setup

3-D rendering of drama setup

CATT-Acoustic Screenshots

3-D rendering of lecture setup

Comparison of orchestra setup with Boston Symphony Hall

Comparison of drama setup with Royal Shakespeare Theatre

CATT-Acoustic Files – Master.geo

;Auditorium - Tyler Dare

;MASTER.GEO

scale 0.3048 0.3048 0.3048

;Changes units from feet to meters

GETGLOBAL SETUP = 1-Orchestra 2-Drama 3-Lecture

INCLUDE BALCONY

IF SETUP = 1 THEN

INCLUDE SHELL

ENDIF

IF SETUP = 2 THEN

INCLUDE CEILING

INCLUDE PANELS

ENDIF

IF SETUP = 3 THEN

INCLUDE CEILING

INCLUDE CHALKBOARD

INCLUDE PANELS

INCLUDE SEPARATOR

ENDIF

;absorption and scattering coefficients 125Hz to 4kHz [%], RGB-color

;ABS audience = <40 50 60 70 80 80> L <30 40 50 60 70 80> { 255 0 0 }

;Foor - wood on joists

ABS wood = <15 11 10 7 6 7> L <30 30 30 30 30 30> { 194 120 65 }

ABS d = <50 50 50 50 50 50>

;Audience seats - fully occupied, fabric upholstered

ABS aud = <60 74 88 96 93 85> L <30 40 50 60 70 80> { 255 0 0 }

;Walls - plaster on lath

ABS plaster = < 2 3 4 5 4 3 > {210 210 210}

;Ceiling - Acoustic ceiling tiles

ABS ceiling = <70 66 72 92 88 75> {150 230 230}

;Flyspace - high absorption from hanging curtains

ABS Flyspace = <90 90 90 90 90 90> {0 0 0}

;ABS Shell = <28 22 17 9 10 11> {60 97 196}

;Curtain - high absorption on back wall

ABS curtain = < 14 35 55 72 70 65 > {255 255 0}

ABS curtain1 = < 14/12 35/15 55/18 72/10 70/6 65/5 > {255 255 0}

CORNERS

;Permanent walls

01 100 75 0

02 50 75 0

03 0 75 8

04 0 0 8

05 50 0 0

06 100 0 0

07 100 75 5

08 113 75 5

09 113 65 5

10 117 65 5

11 150 55 5

12 150 20 5

13 117 10 5

14 113 10 5

15 113 0 5

16 100 0 5

17 113 0 65

18 0 0 65

19 0 75 65

20 113 75 65

21 113 10 28

22 117 10 28

23 113 65 28

24 117 65 28

25 117 65 65

26 117 10 65

27 150 20 65

28 150 55 65

;Front audience

29 55 70 0

30 55 40 0

31 55 35 0

32 55 5 0

33 95 70 0

34 95 40 0

35 95 35 0

36 95 5 0

37 55 70 3.5

38 55 40 3.5

39 55 35 3.5

40 55 5 3.5

41 95 70 3.5

42 95 40 3.5

43 95 35 3.5

44 95 5 3.5

;Rear audience

45 50 70 0

46 50 40 0

47 50 35 0

48 50 5 0

49 0 70 8

50 0 40 8

51 0 35 8

52 0 5 8

53 50 70 3.5

54 50 40 3.5

55 50 35 3.5

56 50 5 3.5

57 0 70 11.5

58 0 40 11.5

59 0 35 11.5

60 0 5 11.5

;Curtains

301 118 60 65

302 118 60 35

303 118 15 65

304 118 15 35

305 130 58 65

306 130 58 35

307 130 17 65

308 130 17 35

309 140 55 65

310 140 55 35

311 140 20 65

312 140 20 35

PLANES

;Permanent walls

[01 Floor / 01 02 05 06 / wood]

[02 Slope Floor / 02 03 04 05 / wood]

[03 Back Wall / 19 18 04 03 / curtain]

[04 Audience Ceiling / 20 17 18 19 / plaster]

[05 Audience Front Wall / 17 20 08 09 23 21 14 15 / plaster]

[06 Stage Floor / 07 16 15 14 13 12 11 10 09 08 / wood]

[07 Apron Front / 16 07 01 06 / wood]

[08 Separator Top / 24 22 21 23 / plaster]

[09 Separator SL Side / 21 22 13 14 / plaster]

[10 Separator SR Side / 24 23 09 10 / plaster]

[11 Aud SL Wall / 18 17 15 16 06 05 04 / plaster]

[12 Aud SR Wall / 20 19 03 02 01 07 08 / plaster]

[13 Stage SL Wall / 26 27 12 13 / plaster]

[14 Stage SR Wall / 28 25 10 11 / plaster]

[15 Stage Back Wall / 27 28 11 12 / curtain]

[16 Fly Ceiling / 28 27 26 25 / flyspace]

[17 Separator Back / 25 26 22 24 / plaster]

;Front audience area

[18 SL Aud Top \ 43 44 40 39 \ aud]

[19 SL L Side \ 40 44 36 32 \ aud]

[20 SL R Side / 39 43 35 31 / aud]

[21 SL Front / 43 44 36 35 / aud]

[22 SL Back / 40 39 31 32 / aud]

[23 SR Aud Top / 42 41 37 38 / aud]

[24 SR L Side / 42 38 30 34 / aud]

[25 SR R Side / 41 33 29 37 / aud]

[26 SR Front / 41 42 34 33 / aud]

[27 SR Back \ 37 38 30 29 \ aud]

;Rear audience area

[28 Rear SL Aud Top /60 56 55 59 / aud]

[29 Rear SL L Side / 56 60 52 48 / aud]

[30 Rear SL R Side \ 55 59 51 47 \ aud]

[31 Rear SL Front / 55 56 48 47 / aud]

[32 Rear SL Back / 60 59 51 52 / aud]

[33 Rear SR Aud Top / 54 53 57 58 / aud]

[34 Rear SR L Side / 54 58 50 46 / aud]

[35 Rear SR R Side / 53 45 49 57 / aud]

[36 Rear SR Front / 45 53 54 46 / aud]

[37 Rear SR Back \ 57 58 50 49 \ aud]

;Curtains

[*3 D 60 Stage Curtain / 4 4 4 4 / 301 302 304 303 / curtain]

CATT-Acoustic Files – Balcony.geo

scale 0.3048 0.3048 0.3048

CORNERS

;Balcony Structure

601 0 0 38

602 40 0 32

603 40 0 34

604 0 0 44

605 0 75 38

606 40 75 32

607 40 75 34

608 0 75 44

;Audience Area

609 5 5 46.5

610 5 70 46.5

611 35 70 38.5

612 35 5 38.5

613 5 5 43

614 5 70 43

615 35 70 35

616 35 5 35

PLANES

;Balcony Structure

[100 Balcony Top / 608 604 603 607 / plaster]

[101 Balcony SL Side / 601 602 603 604 / plaster]

[102 Balcony SR Side / 608 607 606 605 / plaster]

[103 Balcony Underside / 605 606 602 601 / plaster]

[104 Balcony Front / 603 602 606 607 / plaster]

[105 Balcony Aud Top / 609 612 611 610 / aud]

[106 Balcony Aud Front / 612 616 615 611 / aud]

[107 Balcony Aud SR Side / 610 611 615 614 / aud]

[108 Balcony Aud SL Side \ 609 612 616 613 \ aud]

[109 Balcony Aud Back / 609 610 614 613 / aud]

CATT-Acoustic Files – Ceiling.geo

scale 0.3048 0.3048 0.3048

CORNERS

;Movable Ceiling

61 113 0 28

62 113 75 28

63 40 75 33.5

64 40 0 33.5

PLANES;Movable Ceiling

[D 38 Movable Ceiling / 64 63 62 61 / ceiling]

CATT-Acoustic Files – Chalkboard.geo

scale 0.3048 0.3048 0.3048

ABS Chalkboard = <1 1 2 2 2 3> {50 150 100}

CORNERS

401 116 12 8

402 116 12 14

403 116 63 14

404 116 63 8

PLANES

[70 Chalkboard / 401 402 403 404 / chalkboard]

CATT-Acoustic Files – Panels.geo

scale 0.3048 0.3048 0.3048

CORNERS

;Panels

81 10 .5 15

82 10 .5 30

83 25 .5 30

84 25 .5 15

85 35 .5 12.5

86 35 .5 27.5

87 50 .5 27.5

88 50 .5 12.5

89 60 .5 10

90 60 .5 25

91 75 .5 25

92 75 .5 10

93 85 .5 10

94 85 .5 25

95 100 .5 25

96 100 .5 10

181 10 74.5 15

182 10 74.5 30

183 25 74.5 30

184 25 74.5 15

185 35 74.5 12.5

186 35 74.5 27.5

187 50 74.5 27.5

188 50 74.5 12.5

189 60 74.5 10

190 60 74.5 25

191 75 74.5 25

192 75 74.5 10

193 85 74.5 10

194 85 74.5 25

195 100 74.5 25

196 100 74.5 10

PLANES

;Panels

[50 Panel1 / 81 82 83 84 / curtain]

[51 Panel2 / 85 86 87 88 / curtain]

[52 Panel3 / 89 90 91 92 / curtain]

[53 Panel4 / 93 94 95 96 / curtain]

[54 Panel1 \ 181 182 183 184 \ curtain]

[55 Panel2 \ 185 186 187 188 \ curtain]

[56 Panel3 \ 189 190 191 192 \ curtain]

[57 Panel4 \ 193 194 195 196 \ curtain]

CATT-Acoustic Files – Separator.geo

scale 0.3048 0.3048 0.3048

CORNERS

;Movable Partition

501 51 0 0

502 51 75 0

503 51 75 31.61

504 51 0 31.61

PLANES

[D 90 Partition / 501 502 503 504 / curtain1]

CATT-Acoustic Files – Shell.geo

scale 0.3048 0.3048 0.3048

;Shell is made of 3/8" plywood

ABS Shell = <28 22 17 9 10 11> {60 97 196}

CORNERS

loop(100,angle,0,90,10,117+16.5*cos(angle),-5*angle/90+15,5+23*sin(angle))

loop(200,angle,0,90,10,117+16.5*cos(angle),5*angle/90+60,5+23*sin(angle))

PLANES

;Shell

[39 Shell 1 / 100 101 201 200 / shell]

[40 Shell 2 / 101 102 202 201 / shell]

[41 Shell 3 / 102 103 203 202 / shell]

[42 Shell 4 / 103 104 204 203 / shell]

[43 Shell 5 / 104 105 205 204 / shell]

[44 Shell 6 / 105 106 206 205 / shell]

[45 Shell 7 / 106 107 207 206 / shell]

[46 Shell 8 / 107 108 208 207 / shell]

[47 Shell 9 / 108 109 209 208 / shell]

CATT-Acoustic Files – SRC.LOC

scale 0.3048 0.3048 0.3048

SOURCEDEFS

IF SETUP = 1 THEN

a0 125 37.5 10 catt.sd1 50 37.5 3

ENDIF

IF SETUP = 2 THEN

a0 125 37.5 10 catt.sd1 50 37.5 3

ENDIF

IF SETUP = 3 THEN

a0 110 37.5 10 catt.sd1 70 37.5 3

ENDIF

Lp1m_a = Lp_voice_normal

Gain_a = <10 10 10 10 10 10>

Delay_e = 0

CATT-Acoustic Files – REC.LOC

Scale 0.3048 0.3048 0.3048

RECEIVERS

IF SETUP = 1 THEN

01 50 37.5 3.5

02 75 20 3.5

03 75 55 3.5

04 20 20 7.5

05 20 55 7.5

06 20 37.5 42.5

ENDIF

IF SETUP = 2 THEN

01 50 37.5 3.5

02 75 20 3.5

03 75 55 3.5

04 20 20 7.5

05 20 55 7.5

ENDIF

IF SETUP = 3 THEN

01 70 37.5 3.5

02 75 20 3.5

03 75 55 3.5

ENDIF