Theatre Design & Technology - Fall 1979 - 31

the audience, but they must never be greater than NC-25.
experience is that noise levels in any critical theatre area
dience, stage, or control room) greater than NC-25 pose
hearing problems for the audience, actors, and technical
sonnel.

I

f-

i=

t= i= t=:

'0

t=: 1-'J-l-t

-f- l .R

f-!
r------j

t
!

rr -

--j

~

'",

r---

'-

,
~

I - f- l -

i---

I\K.

)1

t:-

~"

r------ ~f- 11=
,-

*

~r--

r·

"L

--

(

, Hi

t

\

'-.-+-

20

'.

N'

I" i -. . '
I

t"

L.

--,- f-

l---

r- I-\T

',-;-

.

I--'",

,

H-

~

~

~~

I

1.1

"

"

t

f- f-

63

125

250

500

OCT AVE B.;rm CENTER FRE UErICIES

I

~

1000
Ir~

2000

l=-

\

F=

t=

\

~- f-

-

"

f-

=

t-

b

-

1\"'1

;-

o
31 5

,

t==
I=-

C

-I- I·· ..

-

t=t=

f
>,1. " '.1\
."

-.
'0

I-

I
~

~

f--\

r=
r=
r=
r=

-

f-.--

t !-

1--

I

r

-'-1'"

-

''-

~ \.

- 1= I--

=

6000

HZ (cps)

Fig. 1: Background nOise In 1'10 heatres, and thea re NC curves,
The above NOise Cn ena Curves remain In use by many acoustical cOn!:.u/ants and mechanical englfleers, at hough they Will be replaced In the near future by a new set of curves, These curves show the maximum levels that can
be tolerated In each octave band for particular uses of the space. NC-) 5 IS
commonly accep ed as good for heatres, NC-20 less good, but satisfactory,
and NC-25 the maximum acceptable compromise, Both Russell Johnson Associates and Klepper Marshall King supplied noise control recommendations
for the Neely Theatre at Vanderbilt UniverSity, toward an intended goal of NCt 5, but cost-cut ing compromises dunng deSign development resulted in the
higher, but sll1l sa isfactory. background levels shown, In Thea re "0" imporant recommenda Ions by the acous leal consultan were not followed, and
he mechanical sys em IS much 00 nOIsy 0 be used a ull speed, while halfspeed opera Ion lea es some problems unsolved In some sea s.

use of the dB(A) rating system for theatres is fraught with peril
and usually admits too much low-frequency noise,
A background noise level below the threshold of hearing
would be optimal in any theatre. However, as with all other aspects of design, practical considerations (more directly, economics) force compromises. NC-15 is the criterion specified
by most acoustical consultants for critical projects, such as
most theatres, concert halls, and studios. The highest, least
restrictive (to the mechanical engineer) background noise design level that should be considered in any theatre is NC-25,
and this level only in a tight-budget, smaller-sized theatre. NC20 is a widely used criterion, since it falls between the nearsilence of NC-15 and the clearly audible, but low-level NC-25
boundaries. Note that some acoustical consultants believe a
criterion even more strict than NC-1 5 is necessary for certain
theatre projects. Not only must the audience area of a theatre
be quiet, but the stage areas and control booths open to the
theatre must also be quiet. Sometimes we permit levels in the
control booths and on stage to be 5 dB higher than levels for

Our
(aureal
per-

Noise Sources and Transmission Paths
Noise from mechanical systems entering a theatre can be
classified in three ways: airborne, ductborne, and structureborne. The airborne component would include the noise
of machinery outside the theatre heard inside the theatre due
to poor sound-isolation qualities of the theatre's enclosing
walls, ceiling, floor, doors, windows, etc., plus noise generated at diffusers, grilles, and any return-air "mushrooms."
Ductborne noise is noise originating in the mechanical equipment room or the ducts themselves, transmitted to and from
sensitive spaces by ducts, and exiting at supply and return
grilles, diffusers, and mushrooms. Structureborne noise and
vibration are generated by vibrating sources, such as mechanical equipment, contacting structural elements common
with the theatre. Once in the building structure, vibrations may
travel long distances with little loss, radiating audible noise
along the way.
The possible sources affecting a theatre's heating, ventilating, and airconditioning system include fans, pumps, compressors, condensers, cooling towers, ductwork, dampers,
and terminal devices, such as diffusers, grilles, and mushrooms. All these sources except ductwork, dampers, and terminal devices should be located at some distance from the
theatre, and all but terminal devices are sources of both airborne and structureborne noise. Fans can be a source of
ductborne noise in most circumstances, and the design of
ductwork in the mechanical equipment room can allow even
noise from pumps, compressors, etc., to enter ductwork as
well. Upstream dampers, diffusers, and ductwork turns and divisions contribute ductborne noise alone.
Airborne noise is best controlled by locating equipment remotely. Also, the intervening structure should effectively isolate the theatre from this equipment. Structureborne noise is
controlled by spring-mounting the vibrating equipment to reduce the vibration transmitted to building structure, by insuring that all pipes, ductwork, and conduit connections to the vibrating equipment have vibration isolation measures installed,
and by building discontinuities, such as separation joints, into
the building structure to interrupt the transmission path. Care
in diffuser selection and ductwork design will prevent airborne
noise generated by diffusers in the sensitive spaces. Ductborne noise is controlled primarily by the installation of internal duct lining and commercial duct silencers, plus the use of
low, low air velocities. The lining and commercial duct silencers control ductborne transmission of fan and other equipment noise entering in the mechanical equipment room, while
low velocities are necessary to reduce air-turbulence noise.
Other measures include lagging (enclosing the ductwork in
sensitive spaces or in mechanical equipment rooms), and the
use of low-transmission-Ioss glass fiber ductwork to bleed off
low-frequency energy into non-sensitive spaces. Generally,
the high- and mid-frequency portion of mechanical system
noise is due to air turbulence at diffusers, in small ducts, and
at dampers; and the low-frequency noise is due to air turbulence in large ducts, fan noise, and vibrating equipment.

Noise and Vibration Control in Mechanical
Equipment Rooms
The task of mechanical room noise control is greatly simplified if the mechanical equipment room is located on- or below-grade, at some distance from the theatre interior. Nearby
mechanical rooms will always pose problems, but these problems can be somewhat reduced when the rooms contain only
equipment that serves the theatre, not the rest of the building.
The worst possible situation is to have fans and condensers



Table of Contents for the Digital Edition of Theatre Design & Technology - Fall 1979

Contents
Theatre Design & Technology - Fall 1979 - 1
Theatre Design & Technology - Fall 1979 - 2
Theatre Design & Technology - Fall 1979 - 3
Theatre Design & Technology - Fall 1979 - Contents
Theatre Design & Technology - Fall 1979 - 5
Theatre Design & Technology - Fall 1979 - 6
Theatre Design & Technology - Fall 1979 - 7
Theatre Design & Technology - Fall 1979 - 8
Theatre Design & Technology - Fall 1979 - 9
Theatre Design & Technology - Fall 1979 - 10
Theatre Design & Technology - Fall 1979 - 11
Theatre Design & Technology - Fall 1979 - 12
Theatre Design & Technology - Fall 1979 - 13
Theatre Design & Technology - Fall 1979 - 14
Theatre Design & Technology - Fall 1979 - 15
Theatre Design & Technology - Fall 1979 - 16
Theatre Design & Technology - Fall 1979 - 17
Theatre Design & Technology - Fall 1979 - 18
Theatre Design & Technology - Fall 1979 - 19
Theatre Design & Technology - Fall 1979 - 20
Theatre Design & Technology - Fall 1979 - 21
Theatre Design & Technology - Fall 1979 - 22
Theatre Design & Technology - Fall 1979 - 23
Theatre Design & Technology - Fall 1979 - 24
Theatre Design & Technology - Fall 1979 - 25
Theatre Design & Technology - Fall 1979 - 26
Theatre Design & Technology - Fall 1979 - 27
Theatre Design & Technology - Fall 1979 - 28
Theatre Design & Technology - Fall 1979 - 29
Theatre Design & Technology - Fall 1979 - 30
Theatre Design & Technology - Fall 1979 - 31
Theatre Design & Technology - Fall 1979 - 32
Theatre Design & Technology - Fall 1979 - 33
Theatre Design & Technology - Fall 1979 - 34
Theatre Design & Technology - Fall 1979 - 35
Theatre Design & Technology - Fall 1979 - 36
Theatre Design & Technology - Fall 1979 - 37
Theatre Design & Technology - Fall 1979 - 38
Theatre Design & Technology - Fall 1979 - 39
Theatre Design & Technology - Fall 1979 - 40
Theatre Design & Technology - Fall 1979 - 41
Theatre Design & Technology - Fall 1979 - 42
Theatre Design & Technology - Fall 1979 - 43
Theatre Design & Technology - Fall 1979 - 44
Theatre Design & Technology - Fall 1979 - 45
Theatre Design & Technology - Fall 1979 - 46
Theatre Design & Technology - Fall 1979 - 47
Theatre Design & Technology - Fall 1979 - 48
Theatre Design & Technology - Fall 1979 - 49
Theatre Design & Technology - Fall 1979 - 50
Theatre Design & Technology - Fall 1979 - 51
Theatre Design & Technology - Fall 1979 - 52
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2022winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2022winter_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2021fall_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2021fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2021summer_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2021summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2021spring_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2021spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2021winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2021winter_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2020fall_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2020fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2020summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2020summer_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2020spring_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2020spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2020winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2020winter_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2019fall_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2019fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2019summer_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2019summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2019spring_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2019spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/usitt_techexpoguide_2019_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/usitt_techexpoguide_2019
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2019winter_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2019winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2018fall_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2018fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2018summer_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2018summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2018spring_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2018spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2018winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2017fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2017fall_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2017summer_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2017summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2017spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2017spring_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/usitt_techexpoguide_2017_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/usitt_techexpoguide_2017
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2017winter_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2017winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2016fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2016summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2016spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2016spring_public
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2016winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2015fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2015summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2015spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2015winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2014fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2014summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2013winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2013summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2013fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2013spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2012winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2012fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2012summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2012spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2011winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2011fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2011summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2011spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2010winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2010fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2010summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2010spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2009winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2009fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2009summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2009spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2008winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2008fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2008summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2008spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2007winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2007fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2007summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2007spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2006winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2006fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2006summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2006spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2005winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2005fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2005summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2005spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2004winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2004fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2004summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2004spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2003winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2003fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2003summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2003spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2002winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2002fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2002summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2002spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2001winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2001fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2001summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2001spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2000winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2000fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2000summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_2000spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1999winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1999fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1999summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1999spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1998winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1998fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1998summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1998spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1997winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1997fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1997summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1997spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1996winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1996fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1996summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1996spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1995winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1995fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1995summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1995spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1994winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1994fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1994summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1994spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1993winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1993fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1993summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1993spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1992winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1992fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1992summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1992spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1991winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1991fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1991summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1991spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1990fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1990summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1990spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1989winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1989fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1989summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1989spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1988winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1988winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1988fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1988summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1988spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1987winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1987fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1987summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1987spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1986winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1986fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1986summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1986spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1985winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1985fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1985summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1985spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1984fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1984summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1984spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1983winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1983fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1983summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1983spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1982winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1982fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1982summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1982spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1981winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1981fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1981summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1981spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1980winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1980fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1980summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1980spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1979winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1979fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1979summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1979spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1978winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1978fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1978summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1978spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1977winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1977fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1977summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1977spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1976winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1976fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1976summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1976spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1975winter
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1975fall
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1975summer
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1975spring
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1974Dec
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1974Oct
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1974May
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1974Feb
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1973Dec
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1973Oct
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1973May
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1973Feb
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1972Dec
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1972Oct
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1972May
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1972Feb
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1971Dec
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1971Oct
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1971May
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1971Feb
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1970Dec
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1970Oct
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1970May
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1970Feb
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1969Dec
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1969Oct
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1969May
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1969Feb
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1968Dec
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1968Oct
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1968May
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1968Feb
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1967Dec
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1967Oct
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1967May
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1967Feb
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1966Dec
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1966Oct
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1966May
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1966Feb
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1965Dec
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1965Oct
https://www.nxtbook.com/nxtbooks/hickmanbrady/tdt_1965May
https://www.nxtbookmedia.com