cenla sound lab

CENLA SOUND LAB RECORDING STUDIO

COMPLEX

By

James D. Knight

A THESIS

IN

ARCHITECTURE

\

Submitted to the Architecture Faculty of the College of Architecture of Texas Tech University in

Partial Fulfillment for the Degree of

CHITECTURE

Chairman of the Committee

Programming Instructor (ARCH 4395): Prof. G. Lehmann Design Critic (ARCH 4631): Prof. G. Lehmann

jan, College of Architecture

May 1989

Ft PROGRAM OUTLINE K)SZ.

, 2 ^ 1 THESIS STATEMENT / INTRODUCTION

2 BACKGROUND

A. Technical Demands B. Case Study Evaluation

3 DESIGN FOCUS

A. Technical Aspects B. Activity / Space Analysis C. Site Information

4 BIBLIOGRAPHY

5 TECHNICAL APPENDIX

THESIS STATEMENT / INTRODUCTION

As the business of entertainment, and the music industry in

particular, grows at a rapid rale, the need for high quality, efficient

recording studios becomes more evident. As a practicing musician, I can

identify with the needs, desires, and demands placed on the recording

industry by today's artists.

The sound recording studio, as we know it today, began to take

shape in the late 1950's. However, the rate of technical advancement

during the 1960*s put studio design in the awkward position of adapting

or becoming quickly obsolete. Experiments with reverberation control

and use, sound diffusivily and symmetry, and room reflections, etc.,

have all forced design, as weU as construction materials and methods to

change with the increasing knowledge and sophistication.

Unfortunately, the vast majority of music studios have not been

designed by architects. In most instances, existing buildings are

convened and renovated into workable studios, usually by sound

engineers. However, as a result of their evolution, these structures lack

the design qualities that architects are able to create.

As an architect, it would be a challenge not only to meet the

physical requirements, but to create a comfortable and relaxing

atmosphere in which artists may produce their work, and receive a degree

of inspiration from the surroundings. Most importantly, it is a challenge

to the designer to make an architectural statement on the landscape. As a

musician, I understand the fact that much of the finished product, which

makes up the final mastered tapes, is actually realized by the musicians

while in the studio, and not completely preconceived. Therefore, I think

It vital to provide for this creative process in every way possible.

Because the studio complex is a technology-based facility, it is my

intention to develop the design primarily through technology-based

theories, analogies, and concepts, to fiirther dramatize this aspect. I view

this project as an opportunity to demonstrate the 'state of the architecture',

emphasizing today's technology through exposed structure, construction,

and materials - the direction which I believe architecture to be taking. One

of the most significant facets, acoustics, must remain in the designer's

thoughts throughout the design process, and must be of high priority at all

times. This idea should remain especially throughout the choosing of

materials and construction methods, since these ultimately affect

acoustics, and thus the outcome of the recordmg.

In terms of technology and construction, my primary concerns are these:

The control of reverberation within the enclosure The proper dijfusion of sound within the enclosure

The protection of the enclosure from interfering outside noise

To accomplish these goals, the choice of building materials and

their use in construction is of utmost importance. Achievement of low

levels in a studio to permit flexible operation is something to be concemed

with from the outset. Acoustical information must be gathered and

analyzed in the preliminary stages of the project. Often, the problem of

controlling noise becomes one of great difficulty, but this concern is not

insurmountable. There is, however, an economic limit to what can be

done to provide noise control. Each path by which noise may enter must

be examined, and costs of control evaluated so that a balanced design can

be achieved. Only with proper precautions will noise be adequately

controlled so that the studio may be used freely, as intended. The

confines of this recording complex will be designed to house four fully

equipped studios, with expansion capabilities for a total of eight. This

allows several groups of musicians to record similtaneously with minimal

limitations. Each unit will be suited to handle approximately fifteen to

eighteen people including musicians, guests, and studio personnel. Each

will also contain adequate storage for equipment not in use at that

particular time. Also included will be administrative office space. The

facility will provide a snack bar, lounge, and recreation area for break

periods and relaxation. Since countless hours are involved with

professional recording sessions, private room accomodations will be

provided.

A recording studio should not only represent the state of the art in

sound reproduction methods and techniques, but should also be highly

versatile and efficient, providing musicians, producers, engineers, and

studio technicians with an atmosphere that is a pleasure to work in, since

an abundance of frustration is experienced in this profession. A location

that provides a degree of serenity is of strong benefit. At the same time,

the location of the complex should be convenient to major transportation

facilities, highway systems, and lodging. The area chosen for the site is

just south of Alexandria, Louisiana. Being quite familiar with this part of

the country, this centrally located city, where several of the state's

highways converge, would offer an ideal location for such a project, not

only on a state-wide scale, but to serve a large portion of the deep south,

as well. Existing studios in Alexandria, and all of central Louisiana, are

relatively low in quality. However, these studios are heavily used,

indicating the need for a first quality recording facility in that region. The

site, peacefully located in the countryside, is just minutes from

downtown and the airport, and is highly accessible to a variety of

recreational activites in and around the city to serve the users' needs for

breaks and relaxation.

Having a strong interest in music and the music profession, this is an

opportunity for me to create a recording complex that would serve as the

ultimate environment for completing the proposed function: Creating,

arranging, and reproducing a work of art in music.

8

BACKGROUND

lECHNICAL DEMANDS

Some have attributed it to the technological explosion in the science

of sound reproduction in the last fifteen years. Others have pointed to the

cultural revolution of the 1960's, ushered in by the likes of the Beatles

and the Rolling Stones, which made music a pivotal force in the lives of

so many. Still others have pointed to the new musicians, composers, and

writers, whose search for artistic freedom has led in directions never

considered twenty years ago.

Whatever the reason, the recording studio phenomenon is

exploding. In 1960, there were only several hundred professional

recording studios in the United States. By 1978 there were over ten times

that number. By 1984, semi-professional and home studios, which were

almost nonexistent in 1960, number an estimated 50,000.

Acoustics is the science of sound, including its production,

transmission, and effects. Although it is derived from a Greek word

meaning to hear, its meaning has been extended to include sound beyond

the limits of hearing. Acoustics is a broad field which embraces music,

radio, sound reproduction, sonar, and many other specialized subjects of

only passing interest to most architects.

Occasionally, nature provides an ideal environment for some human

activities. The architect, however, is often called upon to provide a

full-time, ideal environment to suit an activity which a man chooses to do.

A building is a controlled environment which facilitates human activity

and influences human conduct and attitudes. Sound is an integral and

10

vital part of any environment. To the architect, it is almost like a building

material - a medium which can be molded, directed, and manipulated to

create the sought after environment.

It is somewhat unfortunate that the term acoustical materials has

become a part of our technical vocabulary, since this suggests a family of

unique, specific materials with unique properties. Actually, all materials

are acoustical materials in the sense that they absorb, reflect, or ra4iate

sound, and damp vibrations. The acoustical characteristics of all materials

are as basic as their density, elasticity, or hardness. In fact, the acoustical

characteristics of materials are directly related to the basic physical

properties of the materials. This should be taken into account when a

material is considered during design.

During the past few decades, a collection of misconceptions about

acoustics and acoustical materials has been developed, even among the

technically trained. Acoustical materials are essentially transducers.

Usually they convert some of the sound energy which reaches them to

thermal energy. The reflection, transmission, radiation, and absorption

of acoustic energy by various materials constitutes essentially the whole

field of sound and vibration control.

SOUND

Sound is the sensation caused by the vibration of the ear drum.

When an object or source is caused to vibrate, a series of pressure

impulses is created in the surrounding air. As these impulses strike the

eardrum they are translated into minute electrical signals which are, in

tum, sent to the brain.

WAVES

When a source, such as a guitar string, is set into motion, the

surrounding air reacts in an elastic manner. It is altemately compressed

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and expanded by the rapid back and forth movement of the vibrating

object. One complete cycle is called a wave.

As successful waves are formed, they travel outward in a spherical

pattem, in much the same way that water waves travel outward from a

splash.

FREQUENCY

The speed with which the waves are regularly produced is called the

frequency of vibration and is measured in cycles per second or hertz. The

length of time taken for one complete cycle is called the period of

vibration. Humans can hear frequencies in the approximate range of 20

to 20,000 Hz. This range is often referred to as the audible spectrum.

The frequency of sound is related to the pitch heard by the ear. In

general, the higher the frequency, the higher the pitch.

VELOCITY

In air, sound pressure waves travel outward from the source at

approximately 1,130 feet per second. This is commonly referred to as the

velocity of sound. This velocity varies slightly with air temperature and

humidity.

In solid materials such as wood and steel, sound travels much more

quickly (11,700 and 18,000 feet per second, respectively). These

materials are more elastic than air, which means their molecules tend to

bounce back more quickly when deflected by a sound source. The result

is that a vibrational impulse is easily sent through wood or steel,

accounting for the remarkable ability of most buildings to conduct sound

directly through their structural framework.

INTENSITY

At any given distance from a sound source, the sound wave has a

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characteristic intensity. The intensity decreases rapidly as the wave

travels outward. Specifically, intensity diminishes according to the

square of distance traveled.

The intensity of a sound field is defined as the flow of acoustic

power, in watts, through a given area, in square meters. Thus, sound

intensity is measured in watts per square meter.

SOUND PRESSURE

Intensities of everyday sounds are extremely difficult to obtain.

They caimot be looked up on a chart or measured with a simple

instrument. This is because intensity represents a mathematical ideal

more closely than a physical quantity.

However, pressure is fortunately related to intensity and can be

measured using a relatively simple device: the microphone. Therefore,

most acoustical measurements given in decibels (dB) are actually sound

pressure levels, rather than intensity levels. The measurements are taken

with a microphone and an instrument that electrically calibrates the output

of the microphone in decibels. Such an instrument is called a sound level

meter.

THE DECIBEL

The decibel is probably the most misunderstood and misused term in

acoustics. This stems from the fact that it does not really measure a

physical quantity. The decibel merely represents a ratio between two

quantities.

As such, the decibel is used for comparing many physical quantities

whose values span a vast range. Thus, for clarification, the term dB

should be followed by an abbreviated reference, describing the quantities

being referred to. Sound pressure levels, for example, are denoted as

dB(spl).

13

REVERBERATION

Reverberation is the gradual decay of sound in a room, after the

source has ceased. It affects the character of all sounds in a room and the

character of any recording being made.

In the studio, it is necessary to be able to control the amount of

reverberation and adjust it to the individual instruments and voices.

When sound waves leave a source, they travel outward in a three

dimensional arc. Some of these waves travel directly to the listener and

are called direct waves. A greater proportion of the waves strike the

walls, floor, ceiling, and room fumishings and are reflected back into the

room. These reflections arrive at the listener in a continuous stream, so

closely spaced that the ear is incapable of distinguishing them as

individual sound waves. Instead, they are perceived as a gradual decay

of the room sound, sometimes lasting several seconds after the source has

stopped altogether.

The reverberation time is a function of two main factors:

the volume of a room

the absorptivity of a room

In a large room, a wave must travel long distances before reaching a

reflective surface. Therefore, the reverberation time is generally longer

for larger rooms, while the reverberation time for a small room is quite

short. The formula for computing reverberation time was derived by

W.C. Sabine and is as foUows: T60 = .049 V / A

where:

T60 = reverberation time (60 dB of decay)

V = room volume (length x width x height) cu. ft.

A = total absorptivity of room, measured in Sabins

frequency of source, room geometry, temperature and humidity of air,

and presence of people, the formula provides only an approximation.

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ABSORPTION

When a sound wave strikes a surface, three phenomena occur:

A portion of the sound energy is transmitted through the barrier

A portion of the energy is reflected back into the room

A portion of the energy is absorbed

'Absorbed' simply means that it has been converted into another

form of energy, generally heat, even though it is scarcely detectable. The

fraction of incident sound energy is absorbed is called the absorption

co-efficient or absorptivity. Therefore, if a certam material absorbed 83%

of all incident sound energy at a particular frequency, its absorption

co-efficient would be .83 at that frequency.

COLORATION

Sometimes, as a result of its size and geometry, a room seems to

'prefer' to accomodate the reverberation of certaui frequencies. This

results in the reinforcing and lingering of certain tones when music is

played. This effect is called coloration.

Coloration is the result of standing waves or room resonances.

These waves whose original vibrations are continuously reinforced by

their own reflections. A typical room has many standing waves and

potential colorations. In the recording environment, these must all be

eliminated.

ECHO

Echo is the repetition of sound due to the delayed arrival of a

reflected sound wave. In order for a reflected wave to be interpreted as a

distant echo, it must arrive at the ear more than 35 milliseconds after the

initial impulse. Sounds arriving before the time are indistinguishable

from the original and are heard as reinforcements of the original wave.

15

Echoes in the studio can completely ruin a recording. The most

common cause of echoes is the hard, reflective surface of the control

room window. Often, a stream of flutter echoes will set up between this

surface and other surfaces in the studio. Occasionally, only a single

reflection wiU bounce off the window and return to the microphone in the

recording area. This latter type of echo is called slapback echo. It is

crucial that both types are eliminated.

SHAPE AND CONFIGURATION

All of the surfaces which enclose a space affect the acoustics within

that space. Surfaces absorb, reflect, focus, diffuse, or diffract the sound

which reaches them. For the most part, a sound wave may be thought of

as similar to a ray of light, and optical analogies can be used to study the

behavior of sound within an enclosure.

Generally, pure geometric shapes tend to be troublesome.

Particularly dangerous are spherical, ellipsoidal, cubical, and cylindrical.

Unfortunately, architectural design tends strongly toward such shapes

under ordinary circumstances.

The dimensions of the studio are important in the relationship to the

sound quality. The smaller the studio dimensions are, the more precise

they need to be. Good reverberation characteristics depend not only on

the proper reverberation time, but also on the uniform rate of decay of

sound. These effects are achieved by the careful shaping of the studio

walls.

Small spaces normally present few difficult problems, but the

severity of acoustical problems tends to increase with the size of the

room. In small rooms, time of travel of the wave front from its source to

the listener is short. Distant echoes rarely occur, and reverberation time is

usually quite short. Although sound in small spaces may be far from

optimum, they are rarely unusable because of their intemal acoustics.

16

In large spaces, echoes, flutter, excessive reverberation,

non-uniform distribution of energy, inadequate levels in areas remote

from the source, excessive concentration in sonie areas, and similar faults

are quite common.

17

CASE STUDY EVALUATION

EXAMINATION OF ISSUES

Glass in the Studio

- the importance of using thick, double-paned glass, separated, and

angled slightly downward to send direct waves to the floor of the studio

and control room.

Lighting

- lights in the recording studio and control room should be bright

enough for visual communication, working of controls, and reading sheet

music and/or lyrics, but should not be glaring or excessive. Through the

use of track lighting and dimmers, lights should be controllable in

brightness and direction.

Studio Building Systems

- the need for using a 'floating' building system when constructing

studio walls, ceiling, and floors to prevent vibration from being

transferred from structure.

Control Room Equipment for Space Allocation

-the need for allowing space in the control room for basic required

recording equipment:

36 channel multi-track recording console

Noise reduction system

Digital reverberator

Digital delay system

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Necessary amplifiers and monitor speakers

24 channel dolby system

Sound Screens

- the need for mobile, cylindrical screens used to provide moderately

reverberant soimd; reverse side lined with sound absorbing material and

arranged so as to not change the acoustic efficiency of the studio.

Studio Setting

- existing studio in Colorado expressing the quality atmosphere

provided by a countryside setting, away from the city and the tension

associated with it.

Isolation Booths

- when isolation booths are intended for drums, absorpant material

should be used on the lower portion of the walls for the low frequency of

the drums, while reflective material should be used on the upper portion

to maximize high frequency given by cymbols.

19

DESIGN FOCUS

20

TECHNICAL ASPECTS

Room acoustics can mean the difference between good and bad

recordings. They affect every phase of the recording process, from the

initial recording session to the final cutting of the disc.

During a recording session, room acoustics are critical. They can

cause instruments and voices to be clearly isolated, or hopelessly

muddled together in a common blur. Acoustical qualities can also have an

important secondary effect at the recording session - on the temperament

of the performers. When the acoustics are excellent, the musicians are apt

to be pleased, and will tend to perform more confidently and

enthusiastically. On the other hand, when the acoustics are poor, the

musicians are likely to feel incapable of communicating with one another

and a lack of cohesiveness may characterize the performance. Thus,

room acoustics may play into the emotional, as well as the technical

quality of a recording.

NOISE

Noise, quite simply, is unwanted sound. It is the first and most

basic element of room acoustics that affects recording. If a recording

environment is noisy, chances are the recording itself will be.

Noise can be produced by an infinite variety of sources whose only

common bond is their undesirability. Noise can never be completely

eliminated - for it is interwoven with the very fabric of our existence.

Despite this, in a recording environment, one must attempt to reduce

21

extraneous noise to its lowest possible threshold. This process is referred

to as soundproofing.

The background noise which is always present in any environment is

known as ambient noise. It can result from traffic, the operation of air

conditioners and other mechanical equipment, or much more subtle

sources such as the rustiing of trees or the falling of rain.

There are several misconceptions about ambient noise and how it is

controlled. The first is that bothersome ambient noise can be eliminated

by applying carpet, curtains, and acoustic tile to the surfaces of a room.

The truth is that these materials do very littie to stop the bulk of sound

energy from entering or leaving a room. Another common misconception

is that a room that sounds quiet to the ear has a low ambient noise level.

This is false because of the human ear's remarkable ability to reject

background noise. We seldom notice sounds which constantiy envelop

us, such as traffic, wind, or continual mechanical noise. Unfortunately, a

microphone picks up these noises immediately and transfers them to the

recording.

SOUNDPROOFING

Sound is a vibratory phenomenon. As long as the studio or control

room is rigidly connected to the immediate environment, the transfer of

sound waves and vibration to and from that environment is inevitable. As

a result, there is a point of diminishing returns beyond which further

sealing and insulation of the studio will not increase its acoustical

isolation.

By separating or floating the construction of the studio from its

immediate surroundings, we can effectively impede the transfer of sound

and vibration to and from the studio.

A floating studio is one whose walls, ceiling, and floor are separated

from the exterior architectural shell by an insulating air space. The

22

floating studio is actually an entire new room built within the existing

structure. The following sections deal with the treatment of the different

components mvolved. The details are applicable to bodi the studio and

control room construction.

WALLS

Noise transmission to and from adjacent spaces can be reduced

considerably by building floating walls separated by an air space from the

existing wall. It is important that these new walls be resilient - that is, not

rigidly connected to any part of the structure. This prevents vibrations

from being transferred from the inner walls to the outer walls, and vice

versa. This resiliency is accomplished by supporting the walls on

vibration-isolation mounting board or by hanging resilient clips. The wall

itself can be made from plywood, plaster board, gypsum drywall

material, or even masonry brick - if the structure can support the load.

The walls should completely surround the entire studio area.

Typical floating walls: woody left and concrete, right

Existing wall

Fibreglas insulation (between studs)

\!7" sound deadening board

Existing wall

Fibreglas insulation

8" concrete block (mortar filled)

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The floating walls should not contact the outer walls at any point.

The new walls should be caulked to eliminate any possible air leaks. The

space between the floating walls and the structure should be lined with a

porous absorbent such as fiberglas.

FLOORS

Wooden floating floors

Even when a room has tremendously insulative walls, sound and

vibration can enter or leave by 'flanked' paths through the structural

floor. To prevent this, a resilient floating floor should be built.

A floating floor is simply a floor surface supported by a

vibration-absorbing medium such as springs, mbber foam, or blankets of

some type. Wooden floating floors improve the vibration and sound

isolation by allowing the adjacent walls to act at their maximum acoustical

efficiency. The most efficient wooden floating floors utilize a heavier

framework supported by specially designed vibration isolators, placed at

regular intervals beneatii die floor. Filling the air space between the

Typical floating floors: Existing floor

Vibration isolator

Finish floor

3 /4" plywood

Sand fil l

Vapor barrier

, 3 /4 " plywood

y/ood

Vibra t ion isolator

, 4 " concrete slab

, Vapor barrier

, 3 4 " pK \ \ood

concrete ^ -

24

support joists with sand increases the mass of the floor substantially,

thereby increasing its isolation performance.

Concrete Floating Floors

A heavy concrete floating floor, working in conjunction with a

substantial structural slab, can eliminate virtually aU vertical transmission

of noise through the studio floor. The basic method for building and

floating a concrete floor is to support the floor at discrete pomts with very

efficient vibration isolators, thus creating a sound-attenuating air space

between the floating floor and the structural floor.

CEILING

A suspended or floating ceiling is an excellent device for attenuating

the sound to and from above. In order to insure the proper degree of

sound isolation, a floating ceiling must be reasonably massive. As a

result, only a durable frame for the ceiling will be suitable. Normally, a

floating ceiling is hung from above, with vibration isolators made from

Floating ceilings:

Suspended from below

Ceiling joist

Fibreglas insulation

Existing ceiling

ciYm:m\ur)'i 2 layers of 5/8" gypsum board

- / r •A:

and from above

Existing ceiling

i,*—Hanging wire

2 layers of 5 /8 " gypsum board

25

neoprene rubber or coiled springs. This insures resiliency and maximum

acoustical efficiency of the ceiling. The periphery of the ceiling should be

1/4 inch clear of the surrounding walls to insure that no rigid contact

occurs. The resulting air space should then be caulked tightly with a

nonhardening compound, and the space above lined with absorbent

material.

DOORS

Doors are the least massive, least airtight part of the floatmg studio's

walls. Thus, they are the weakest link in the sound transmission chain.

To alleviate this problem, each passageway leading out of a studio or

control room should have two doors - one for the inner shell and one for

the outer shell. This creates an air pocket between the doors called a

sound lock.

The larger a sound lock is, the more usable it becomes. When

properly designed, a sound lock can serve as a vocal booth or isolation

room. If properly planned, one central sound lock can take the place of

many small ones by offering access to the control room and the outside

environment, as well as to the studio.

Only solid doors should be used. Laminated double-doors or foam

lined acoustical doors are recommended. Gasketing is a must, and

door-closing hardware is important to insure a tight fit. If the doors are

outfitted with windows, only thick double panes should be used with the

air space between lined with absorptive material.

WINDOWS

Windows, like doors, are a weak link in the studio. For this reason,

strict attention to detail in window construction is of paramount

importance if the isolation of the studio is not to degenerate. It is always

26

necessary to install observation windows for the purpose of visual

communication between the engineers and performers.

The control room window

The control room window is one of the most difficult constructions

in the studio. Visual criteria require that it be large, sometimes up to 200

Control room window detail

Isolation gap

Header beam (size according to span

Fabric over compressed fibreglas

Place compressed fibreglas over isolation gap, sprinkle

with silica gel to maintain relative humidity; cover

with fabric finish

\ ^ ^ - Maintain isolation gap

27

square feet. Unfortunately, glass is a poor sound isolator. Therefore,

control rooni windows are constructed from two or more panes.

The best results are obtained when each pane is placed in an

independent floating wall, so that sound vibration cannot be transferred

from one pane to the other by the adjacent structure. The panes should be

skewed with respect to each other and opposing walls. This measure

helps prevent the formation of flutter echoes and standing waves between

the panes.

Other windows

Very often, it is desirable to incorporate windows other than the

control room observation window into the design of the studio. For

instance, since this studio is isolated in the countryside, it may be

advantageous to open up to a view from within the studio. This type of

amenity may be quite beneficial to the look and feel of the studio, thus

making a more comfortable environment to work and create in.

Using the same construction method as previously presented,

windows to the exterior would not be a problem. It should be noted that

the presence of a large panel of reflective glass wiU influence die interior

acoustics of the studio in a manner that may not always be desirable. For

this reason, the window should be fitted with a thick curtain which can be

drawn to increase flexibility.

VENTILATION

After every effort has been made to close off the studio from the

external environment, the infihration of fresh outside air will be ahnost

completely impeded. As a result, the heat created by the lights,

musicians, and equipment will build very quickly m the air space that

surrounds the inner shell, as well as in the studio.

Installing an isolated air-conditioning and ventilation system is a

complicated matter. The problems that must be solved include:

28

Isolation of compressor and fan noise transmitted through the

building structure.

Isolation of mechanical noises transmitted through the actual

ductwork.

Elimination of air-movement noise through the duct and grill work.

Minimization of air-delivery velocity to eliminate interference with

recording microphones.

Isolation of external noise transmitted through the ductwork.

Controlling the distribution of air to the studio, control room,

isolation booths, and peripheral areas in a manner that provides for

a very responsive control of temperature and humidity under a wide

range of climactic conditions.

The solutions to tiiese problems vary, depending on the final layout

of the studio, the construction, the mechanical equipment chosen, and the

space available.

MECHANICAL EQUIPMENT NOISE AND VIBRATION CONTROL

The mechanical and electrical equipment is a source of many

acoustical problems. The choice of a heating, ventilating, or

air-conditioning system is an acoustical design decision. Nearly every

piece of mechanical equipment in a building is a source of sound and

vibration.

Noise control at the source is ordinarily the most efficient and

economical approach to this problem. Low flow velocities in ducts and

pipes, a minimum of throttling devices or abrupt changes in

cross-section, and good aerodynamic design of all elements in a system

tend to minimize acoustical problems. Any change in a process or

procedure which eluninates noise is invariably more effective than noise

control techniques to do away with acoustic energy already produced.

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Mechanical equipment for a building is probably the most persuasive

noise problem that exists in recording studios. This results from the fact

that most people make insufficient allowance for noise control required

for a mechanical system. Considering the investment in the studio, the

extra effort involved in providing adequate mechanical system noise

reduction will be returned many times over in the usefulness of the

studio.

Probably the most straightforward item of a mechanical system

which can be controlled for noise is the fan. To provide noise control for

the fan, the ducts used to supply air to the studio and surrounding spaces

are lined either with a sound absorbing material such as fiber, or provided

with prefabricated mufflers or silencers.

LIGHTING

Proper lighting in the studio and control room is essential for the

creation of a space that is comfortable and functional. In the studio,

lighting must be powerful enough to provide musicians with the ability to

see one another, communicate, and read music or lyric sheets. On the

other hand, it must not be so excessive that it distracts or interferes with

the emotional aura of the music being recorded.

To satisfy these varying criteria, the lighting system should be

flexible. This means that the lighting fixtures should be movable and

their brightness controllable. Very often, several circuits employing a

combination of white and colored lights are used to maximize flexibility.

Dimmers can also be installed to control brightness.

Track systems, which allow the positioning of lights as well as

interchangeability of fixtures can be effective m conjunction with a fixed

lighting system. Recessed lights, which create punctures in the sound

seal, should be avoided in favor of surface-mounted fixtures. In general.

30

flourescent fixtures should be avoided in studios and control rooms

because of their tendency to induce electrical and acoustical hum.

AESTHETICS

Since the look and feel of a room can have a tremendous effect on

the behavior of the people within the room, it is no surprise that the

aesthetics of a studio often have a profound influence on the music

produced in it. Many studios have become famous for their 'sound'

which is said to be a large component of the successful records produced

in that studio. Very often, this 'sound' is a combination of acoustical

phenomena and the aesthetic presence of the studio on all musicians who

use it.

Most musicians agree that colors should not be too distracting.

Subdued colors are often effective for setting a comfortable mood. As a

rule, colors which are harmonious tend to inspire moods and music with

the same quality. Colors which are flamboyant and outrageous tend to

produce the opposite.

Natural light and views from exterior windows and skylights can

have a stimulating effect, which artificial light can never duplicate.

Natural light creates an open, airy feel in a studio that can be

tremendously inspiring. Natural light also provides an environment in

which plants and trees can flourish, giving the studio the aura of life.

31

ACTIVITY / SPACE ANALYSIS

Because of its highly specialized use, there is a very limited number

of activities which take place in a recording studio. These include band

rehearsals, sound recording, fmal mixes onto master tapes, meetings with

studio personnel, management, agents, producers, record company

representatives, etc., and periods of relaxation.

When designing the recording studio complex, the location and

relationships of the various spaces is crucial. First of all, four fully

equipped studios will be provided, each having its own control room

located adjacentiy. Other provisions include:

MASTER FILING

Storage vaults for the filing of mastered tapes will be provided

adjacent to or near the control room. These spaces must be climate

controlled due to the delicate nature and importance of the final master

recordings.

OBSERVATION AREAS

In some cases, studio observation areas will be provided for guests

to watch the recording sessions take place. While these individuals may

see into the studio, they will have no immediate access. These

observation areas will also have the capability of being closed off easily,

when necessary.

CONFERENCE ROOMS I OFFICES

Centrally located in the complex will be conference rooms to be used

for meetings by musicians, engineers, producers, press, etc., whenever

32

needed. These rooms will be designed to accommodate approximately

eighteen to twenty people.

Also located in this area will be the administrative offices for the

studio manager, chief engineer, assistant engmeers, business manager,

financial manager, and for secretarial use.

PRIVATE ROOM ACCOMMODATIONS

For the benefit of the musicians and their inmiediate staff, private

room acconmiodations will be provided. Suites with adjacent rooms

sharing shower facilities will probably be die most suitable.

LOBBY I RECEPTION

Upon entrance into the complex, the lobby and reception area will

exemplify the technology theme existing throughout the project. This area

will be highly accessible to each of the studios and their observation

areas.

BREAK I RECREATION ROOMS

For much needed time away from the business at hand, a break

room with a snack bar will be provided. Adjacent to this space will be a

recreation room featuring a variety of activities to provide musicians and

staff the opportunity to unwind.

STORAGE

An absolute neccessity to die studio's design is that of adequate and

highly accessible storages areas. These storage rooms should be climate

controlled spaces to protect delicate musical instruments and equipment

from damage. The location of these rooms should minimize the distance

that equipment must be moved and should also be arranged to serve as

sound buffers against adjacent spaces as well.

33

SITE INFORMATION

The location of the site and die building's orientation on diat site can

have a tremendous effect on die performance of a studio. Ambient noise

measurements can differ substantially from one part of a building to

another, depending on die proximity of traffic, mechanical equipment,

and other source noises. In general, if the choice is available, the studio

should located as far from noise producing elements as possible.

Topography can also be used to advantage to improve performance

and reduce construction costs. The site chosen for this proposal exists

near a state highway six miles south of Alexandria, Louisiana. The site is

quite spacious - approximately four square acres, with the area for the

complex on the level ground atop a large knoU, over a hundred and fifty

yards off the highway. The location and configuration of the site will aid

greatly with natural sound breaks; forest on three sides and the slight

curvature of the land providing a buffer against the majority of the

highway's traffic noise.

Existing Site Condition

HIGHWAY

HERE HERE

Use natural barriers (Trees, shrubbery and vegetation are virtually useless!)

34

BIBLIOGRAPHY

36

TEXTS:

Lyle F. Verges, Sound. Noise, and Vibration Control. (New York: Van Nostrand Reinhold Co., 1969).

P.H. Parkin, Acoustics. Noise, and Buildings. (London: Faber and Faber, 1979).

Harry F. Olson, Modem Sound Reproduction. (New York: Van Nostrand Reinhold Co., 1972).

G. Slot, Audio Oualitv. (New York: Drake, 1971).

Glenn D. White, The Audio Dictionary. (Seattle: University of Washington Press, 1987).

Campbell and Created, The Musician's Guide to Acoustics. (New York: Schirmer Books, 1987).

J. Backus, The Acoustical Foundations of Music. (New York: W.W. Norton and Company, 1969).

PERIODICALS:

John Borwick, "The World's First All-Digital Studio," Db-Sound Hngineering Magazine. (March/April, 1985): p. 10

S. Brewster, "Renovations at Montreal Sound," Db-Sound Hngineering Magazine. (February, 1985): p. 31

S. Caine, "Profile: Cherokee Recording Studios," Db-Sound Engineering Magazine. (May/June, 1985): p. 35

37

F.A. Everest, "Acoustic Treatment of Three Small Studios," Journal of Audio Engineering SnHPiy (July, 1968): p.307

J. Corona, "Profile: Howard Schwartz Studio," Db-Sound Engmeerinf^Mp^^yW, (July/August, 1985): p.37

S. Keene, "Tale of die Telearte Recording Studio," Sound Engineering Magazine.. (February, 1983): p.38

F.A. Everest, "Glass in die Studio," Db-Sound Engineering Magazine. (April, 1984): p. 20

M.L. Fischer, "Dallas Sound Lab," Db-Sound Engineering Magazine. (March, 1984): p. 41

M. Rettinger, "Shape of Recording Studios to Come," Journal of die Audio Engineering Societv. (April, 1980): p.237

P.B. Ostergard, "Noise Control for Studios," Joumal of the Audio Engineering Societv. (May, 1975): p.294

P.S. Penner, "Supreme Being Studios," Joumal of the Audio Engineering Society. (May, 1979): p. 249

Y. Shiraishi, "Victor Recording Studios," Joumal of the Audio Engineering Society. (May, 1971): p.405

38

TECHNICAL APPENDIX

39

60 dB LEVEL ^

40 dB WALL

EXISTING 30 dB LEVEL

The wall as a 'sound barrier'

OPEN PLAN

Separate sound sources as far as possible.

I Use furniture and quiet areas to separate activity groups.

Use traffic aisles to define areas.

Space planning for acoustical privacy.

Use noncritic buildings as

Site Planning

HIGHWAY

Use natural barriers

Use natural barriers (Trees, shrubbery and vegetation are virtually useless!)

^r}. \^, /*! I f r I I'l I I I f

R.R. Use walls as barriers

O O N T

Attach equipment rigidly to l ight, large panels or other surfaces.

00 Mount equipment on massive, rigid parts of the structure.

JSK.

00 Separate equipment bases or equipment room floor f rom the structure.

C=l A. S.

CZ3

Minimizing structural transmission of noise and vibration.

O

How sound moves a sound barrier POOR GOOD

Flanking path for airborne sound

n"m l"rr mû'n:m

(III IIII III! II m i

BALLOON FRAMING

Flanking path for airborne sound

Wood plates block airborne sound

WESTERN (OR PLATFORM) FRAMING

Flanking path of airborne sound

.'juii.inu2ut

POOR ISOLATION

Continuous floor slab

Flanking path of airborne sound

Interrupted floor slab

ADEQUATE ISOLATION

"^^^'9.^Ll^t?.y.9^TVÂL HOW TO PREVENT FLANKING STRUCTURAL "FLANKING'

111 i I

STC 60

STC 50

STC 40

STC 30

STC 20

STC 10

MIW SOURCE OF SOUND

PARTITION

THE EFFECT OF UNCAULKED OPENINGS ON STC VALUE OF PARTITION SYSTEMS

(TEST WALL AREA. 100 SQ FT; 12'6' x 8')

T — r 1.4 14 144 1444

TOTAL OPENINGS IN PARTITION SYSTEIVI - SQ IN.

The êct of leaks

RUBBER, STEEL SPRING, OR GLASS FIBER HANGERS AS REQUIRED

ACOUSTICAL SUSPENDED CEILING \ LOW DENSITY GLASS FIBER ACOUSTICAL HANGERS \ »NOISE BARRIER FIBERGLASS

'-GLASS FIBER ISOLATION PADS SUPPORTING FLOATING EQUIPfVlENT ROOM FLOOR

Vibration isolation system for mechanical equipment.

Mechanical Systems Installation

IV)

2" X 4" Wood Studs, 16" on centers (unless otherwise noted)

Construction Weight (lb/ft») STC-Rating

Plans (3/4" = I'O")

1/4" Plywood - Nailed to Studs 2-1/2 24

1/2" Wood Fiberboard - Nailed to Studs 3-1/2 28

1/2" Gypsum Board — Nailed to Studs (Joints Taped and Sealed)

5-3/4 33

szzszsazz; •nBUzzLca.

\ IlllllllltU^

S 05

{_.i<l ^L • *

3/8" Gypsum Lath - Nailed to Studs - 1/2" Sanded Gypsum Plaster (2 Coats)

15

Metal Lath - Nailed to Studs -7/S" Sanded Gypsum Plaster 20 (3 Coats)

35

37 K

3-5/8" Metal Studs, 24" on centers (unless otherwise noted)


H .,;|.

Plans

5/8" Gypsum Board — Screw Attachment to Studs (Joints Taped and Sealed)

39 ranummnnmuj/nl

3-1/4" Metal Studs, 16" on centers (unless otherwise noted)

STC Ratings of Partitions and Walls

Construction Weight (lb/ft») STC-Rating Plans

3/8" Gypsum Lath — Clipped to Studs - 1/2" Sanded Gypsum Plaster (2 Coats)

15 40 CTPWffr' I

Metal Lath — Clipped to Studs - 3/4" Sanded Gypsum 19 Plaster (3 Coats)

37 : ±

Note: Combinations of channels or similar sections to produce a similar air space between opposite surfaces provide approximately the same STC-ratings.

Arrangements of channels or studs to produce completely independent (nonconnected) wythes provide approximately the same improvement in STC-rating (10 points) as staggered studs.

CO

CUMULATIVE IMPROVEMENT OF ANY COMBINATION OF THESE MODIFICATIONS IS CALCULATED THUS:

LARGEST NUMBER + 1/2 NEXT LARGEST + 1/2 NEXT LARGEST, etc.

EXAMPLE:

A "base construction," such as 1/2" Gypsum Board on Wood Studs (STC-33)

Change to: Staggered Studs (+10 points) = 10 points

Add: 4-Absorption in Cavity (+5 points); 1/2(5 points) = 2-1/2 points

Add: 4-One Additional 1/2" Gypsum Board

to One Side Only (+3 points); 1/2(3 points) = 1-1/2 points

TOTAL 14 points

Therefore, "base construction" increases from STC-33 to STC-47.

HOLLOW MASONRY BLOCK WALLS

Construction Werght (lb/ft») STC-Rating Plans

4" Lightweight" 20 36

4" Dense 30 38

6" Lightweight"

6" Dense

8" Lightweight"

28 1

43

34

41

43

46

In^

tm mm 8" Dense 55 48

12" Lightweight" 50 51

12" Dense 80 53

HI

"Sealed against air leakage with 2 coats of sealer paint botti sides or similarly sealed.

The following modifications to the "base constructions" produce the following improvements in STC-rating:

1. Surface Skin Weight:

2. Resilient Attachment of Surface Skin:

rr:rrr'^'^':-• • • • » . i i '

3. Staggered Studs: " " • " ' • " • • I lllLIIIIIUIllllJIIimillllllllllJUILUll]

i i i i . i i i i i iui . l l l l l lui l l l l l l inf i i . l ini in iinimHiiii i iru

4. Slotted Studs:

- . ' ; ' i . ' d :

i I ' >

5. Resilient Damping Board Layer Under Surface Skins (Surface Adhesively Applied):

ilniiauiiui'iiiiiinfliafl

6. Absorption in Cavity:

Doubling 1 Side.. Doubling 2 Sides.

-f-3 points +5 points

ISide.. 2 Sides.

-f 6 points +10 points

+10 points

+8 points

2 Sides +10 points

+5 points

MOVABLE AND OPERABLE PARTITIONS

STC-ratings range from STC-18 to STC-48, depending upon construction, weight, and tightness of seals and closures. Generally, performance parallels comparable fixed-wall construction if edges and perimeters are well-sealed. In practice, it is very difficult to maintain good perimeter seals, and performance tends to be far below ratings.

Floors tend to perform very much like partitions in airborne sound transmission, l-n impact noise (structure-borne) transmission, their response is similar but not identical; a floor with a good STC-rating may not have a good INR-rating. Therefore, each characteristic must be considered independently.

TABLE 3-8 STC-ratings and INR-ratings off Floors

2" X 10" Wood Joists, 16" on centers (unless otherwise noted)

Construction Weight (lb/ft») STC-Rating INR-Rating Plans

1/2" Plywood Subfloors and Standard Oak Flooring — Nailed to Joists

25 - 2 8

Same, Plus 5/8" Gypsum Board Ceiling— Nailed to Underside of Joists

10 37 -17

iTf I rrrmrjrii

• •mnimiiiirtiiftllllllUUj

Same, Except 3/8" Gypsum Lath and 1/2" Sanded Plaster

15 39 -15

iviiU'iiiiU"Mi'u^pnm

Same, Except Metal Lath and 7/8" Sanded Gypsum Plaster (3 Coats)

17 39 -15

WINDOWS AND GLAZING

Construction

D. S. Glass

1/4" Plate Glass

1" Insulating Glass

9/32" Laminated Acoustical Glass'

Glass Block

Spaced Glass ( l /4"-2" Air Space-1/4")

Thickness

1/8"

1/4"

1 "

9/32"

3-3/4"

2-1/2"

Weight (lb/ft»)

1-1/2

3

6-1/2

3-1/4

20

6-1/2

STC-Rating

21

26

32

36

40

42

'"Acousta-pane 36"

DOORS''

1.

Construction

1-3/4" Hollow Core Wood

1-3/4" Solid Core Wood

1-3/4" Hollow Metal

1-3/4" Packed Metal

1-3/4" Special Acoustical

2-1/4" Solid Core Wood

2-1/2" Special Acoustical

•Tully gasketed, all edges and bottom. "Leaky" ratings by 5 to 15 points.

Thickness

1-3/4"

1-3/4"

1-3/4"

1-3/4"

1-3/4"

2-1/4"

2-1/2"

gaskets or no

Weight (lb/ft»)

3-1/2

5

5

7

6

7

8

STC-Rating

26

29

30

32

35

32

38

gaskets can reduce STC-

SOLID. SINGLE-SHEET MATERIALS

Construction

Aluminum

Plywood

Cellulose Fiberboard

Plate Glass

Sheet Steel

Lead

Weight Thickness (lb/ft») STC-Rating

0.025*

l/4«

1/2"

1/4"

1/16*

.35

.73

.75

3.2

18 Gage 2.0

3.9

19

22

22

26

30

34

"STUDLESS" CONSTRUCTIONS

Construction Weight (lb/ft») STC-Rating Plans

2" Panel, Sanded Gypsum Plaster on Metal Lath With or Without Imbedded Channels

18 34 ^ m

Note: Gypsum lath instead of metal lath provides approximately the same STC-rating.

2-1/2" Panel, Sanded Gypsum Plaster on Separate Layers of 19 Qypsum Lath

38

Note: To calculate the effect of variations in weight or air space, refer to page 103. ' Also, see page 36 for the effect of other construction variables.


LARGEST NUMBER + NEXT LARGEST + NEXT LARGEST, etc.

EXAMPLE:

A "base construction," such as Double Solid Dry-wall (STC-46)

Change to: Triple Solid Dry-wall

Add: 2 Air Spaces of 1-1/8" = 5 points

Add: + 1 Layer of 1" Gypsum Board in Cavity = 2 points

Add: + Absorption in One Cavity = 5 points

TOTAL 12 points

Therefore, "base construction" increases from STC-46 to STC-58.

SPECIAL "DRY-WALL" CONSTRUCTIONS


2-1/4" Solid Laminated Gypsum Board

Plans

10

5/8" Gypsum Board Layers Laminated to 1-5/8" x 6" Gypsum Strips

Double Solid Dry-wall — 2 Separate Wythes of 1/2" Gypsum Board Laminated to 1" Gypsum Board with 1-1/8" Air Space

14

30

34

46

IIIWiaillltlllMIIIIUMIIIIimilMlllllMtlllW

- ^ ' ' " ' " ' l n ' . ^ -" ' • ' *

Jllll i l l l l f ^

li'i w%\ffivmm ''..^T.^> '..i,ijniirii!iiiBii

SOLID MASONRY WALLS


4" Brick" 38

8" Brick' 80

12" Brick* 120

41

49

54

6" Reinforced Dense Concrete 75 46



''Careful workmanship; airtight joints or surface sealed.

Plans

4. Resiliently Attached Surface Skin:

5. Absorption in Cavity:

V.'Sa •AV»V/.V#VAV/.'i»^ W

y//////7//7 6. Dividing Wall into Separate

Wythes with 4" Air Space:

t^i>:uur

:?.,;it/f:.7 Si mwmwwmmm. 'initifniitimmm

T

IS ide +12 points 2 Sides +15 points

IS ide +3 points 2 Sides +5 points

+15 points

The following modifications to the "base constructions" produce the following improvements in STC-rating:

1. Sand-Filled Cores: +3 points

2. 1/2" Sanded Plaster (or Similar Surface Skin): 1 Side +2 points

2 Sides +4 points • . . . ' v ' • • ; ' " / ' ' ' • ' • • ) • / 'j

3. Rigidly Furred Surface Skin: IS ide +7 points 2 Sides +10 points


LARGEST NUMBER + NEXT LARGEST + NEXT LARGEST, etc.

EXAMPLE:

A "base construction," such as 4" Lightweight Block (STC-36)

Add: Resilient Plaster Skin One Side = 12 points

Add: + Sand in Cores = 3 points

Add: + Plaster on Opposite Side = 2 points

TOTAL 17 points

Therefore, "base construction" increases from STC-36 to STC-53. -P*-^

PLAN

Control Room Configuration

Drum Booth - Plan, Section

As

req

uir

ed

^ 7

'0"

min

imu

m

•1/2

r- •

f

Overhead trap (broadband absorber)

_ _ ^ F a b r i i

Floating plaltorni

^, Contrcic or sand ti l l

, Vibration isolator

o

Studio t looi

a ; .p • <» 4 » . • ^

SECTION

00

CENLA SOUND LAB RECORDING ^RIS .COMPLEX ALEXANDRIA, LOUISIANA

'^r"'^-J\-' '. utj^i^^y-j^^^^mmM^^:^

w SITE PLAN

5 ^ -T

rvil

a STUDIO CONTROL ROOM b MASTER FILING c STUDIO EQUIPMENT STORAGE d SOUND LOCK e ISOLATION BOOTH f BASS TRAP g MANAGERS OFFICE h CONFERENCE ROOM I RECEPTION J RECORDS OFFICE k ADMINISTRATIVE STORAGE I CUSTODIAL OFFICE

m PRINT ROOM n CUSTODIAL STORAGE o MAIN ENTRANCE p LOADING / UNLOADING q PUBLIC RESTROOMS r JANITORIAL s GENERAL STORAGE t PRIVATE RESTROOMS / SHOWERS u SLEEPING ACCOMMODATIONS V LOUNGE w BREAK / GAME ROOM X EMERGENCY EXITS PLAN

EAST

K SOUTH

WEST

NORTH

ELEVATIONS

2

1

n

SECTIONS / PERSPECTIVES

frame

glass

• water stop

post - tensioned concrete

' reinforcing

• grade beam

" reinforcing

"pier

steel post

concrete slab

expansion joint"

plate -

reinforcing -

pier-

V*

- concrete wall

• dowel

• water stop

- waterproofing

• reinforcing

• slab

O ^

- reinforcing

• insulation

seasonal moisture cfiange

• reinforcing

•pier

flanging wire

channel

truss

corrugated metal deck

lightweight concrete

double layer gypsum

double layer gypsum

double stud wall

double layer gypsum

air space

concrete wall

1 SPINE WALL / FOUNDATION

2 SPINE ROOF / WALL

3 STRUCTURAL COLUMN / FOUNDATIC

4 STUDIO FOUNDATION

5 STUDIO ROOF / CEILING

6 STUDIO WALL

7 COLUMN / CABLE CONNECTIONS 8 TRUSS / CABLE CONNECTIONS

STRUCTURAL DETAILS

cenla sound lab

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