High fidelity loudspeaker system

High fidelity loudspeaker system
United States Patent [191
[11]
4,031,318
Pitre
[45]
June 21, 1977
'
[54] HIGH FIDELITY LOUDSPEAKER SYSTEM
[75] Inventor: Lester M. Pitre, Orleans Parish, La.
[22] Filed:
mentary, closed box-like enclosures, an upper unit con
taining an array of mid-range speakers around three
sides and a lower unit containing arrays of low and high
[73] Assignee: Innovative Electronics, Inc.,
.
namic loudspeaker including two, separate but comple
Jefferson, La.
frequency speakers around three sides. The low fre
Nov. 21, 1975
quency speakers (woofers) on their interior sides in
clude a series of tubes opening into the closed interior
[21] Appl. No.2 634,239
of the speaker enclosure, having various lengths in
[52]
ships. Although the low‘ and high frequency speakers
US. Cl. ............................. .. 179/1 D; 179/1 E;
181/145;181/146;181/147;181/148;
.
[51]
181/155
Int. Cl.2 ................... .. I-I04R l/02; I-IO4R l/20;
I-IO4R 3/12
[58]
Field of Search .............. .. 179/1 E, 1 GA, 1 D;
181/144, 145, 146, 147, 148, 149, 150, 151, I
152, 153, 154, 155, 156, 175, 177,178, 179,
191, 195, 196,’ 197, 199; 333/28 R, 28 T References Cited
[56]
UNITED STATES PATENTS
2,373,692
3,637,039
4/1945
l/l972
Klipsch ..................... .. 181/152
Raichel et a1. ...... ..
181/146
FOREIGN PATENTS OR APPLICATIONS
44-32450
12/1969
Japan ............................... .. 179/1 E
1,244,751
9/1971
United Kingdom .............. .. 179/1 E
accordance withv certain relative, locational relation
include a single crossover frequency circuit, the “mid
range” speakers are not included in any crossover net
work but are driven throughout the total frequency
input range, although a capacitor can be included to
cut off the very low frequencies to the mid-range
speakers. The number of speakers in the arrays in each
unit can be varied, but in the lower unit the over-all
speaker panel sizes remain the same with the speaker
locations on each panel being made asymmetrical
about the horizontal center-line, allowing for altema
tive, up-or-down placement. A protective outer case
about the cabinet can be included having hinged wall
sections, which also serve when opened out as re?ec
tive surfaces, providing a “built-in comer” (FIG. 10).
For easy mobility, ahandle and rollers can be provided
on the back of the unit (FIG. 9). Terminal strip and
electrical hook-ups are provided on the exterior of the
Primary Examiner-George G. Stellar I
speakerlallowing ?exible application and use (FIGS.
Attorney, Agent, or Firm-Pugh & Keaty
[57]
ABSTRACT
A high ?delity loudspeaker system involving a multi
driver, semi-omnidirectional, full range, electrody
7-7C).
11 Claims, 17 Drawing Figures
TWO-WAY SYSTEM
THR EE-WAY SYSTEM
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INVENTION
US. Patent
June 21, 1977
Sheet 1 of 5
4,031,318
US. Patent
June 21, 1977
Sheet 2 0_f5
4,031,318
‘
U.S. Patent
June 21, 1977
Sheet 3 of5
4,031,318
U.S. Patent
June 21, 1977
Sheet 5 of5
4,031,318
KOEQ Pm<
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4,031,318
1
2
HIGH FIDELITY LOUDSPEAKER SYSTEM’
“Audio" Magazine Publications
P.T.O. Class
BACKGROUND OF THE INVENTION
Date
Pages
Article(s)
Subclass
November,
pp. 20, 21 and
“Matrixing"
I79-I.GA
I960
77-8l
and "Sound -
November,
pp. 54, 55 and
namic loudspeaker designed for consumer and com
I960
99, I00
mercial use.
2. General Background
December,
I962
I. Field of the Invention '
4
The present invention relates to a high ?delity loud
speaker system including a multi-driver, electrody
'
'
»
System"
“The Series-
l79-I.GA
~ Parallel Speaker
Array"
pp. l9-22
“Word on Mul-
tiple Speaker's"
l79-l.GA
The two largest problems of the electrodynamic
loudspeakers of the prior art are, ?rstly, one'driver is
unable to reproduce accurately both low and high fre
GENERAL DISCUSSION OF THE PRESENT
quencies, and secondly, as the input power is increased,
the distortion rises as well. Both problems stem primar
ily from the physical limitations of the speaker cone.
In order to be able to reproduce low frequencies, the
driver needs the ability to move large amounts of air. In
contrast, high frequency reproduction requires very .
rapid movements of the cone, with much less actual air 20
moving capacity. Large air. movement requires the
INVENTION
The loudspeaker of the present invention overcomes
these problems and introduces separate arrays for the
low and high frequency bands. The low frequency array
and the unique decoupling networks are not tuned to a
particular frequency. The high frequency array, be—
cause of its unique arrangement, offers excellent dis
persion and phasing characteristics. These two arrays
are combined in a bottom or lower unit in the preferred
cone either to be very large or move large distances.
embodiment of the present invention. In addition, the
Movement of the cone (cone excursion) in large
preferred embodiment of the loudspeaker of the pre
amounts, introduces distortion because a cone near its
full extension will be unable to reproduce another tran 25 sent invention incorporates a separate, full range multi
driver array, designed speci?cally for mid-range use
sient at the same time. So, in order to lower the cone
which in the preferred embodiment is included in a top
excursion and retain large air movement, the area of
or upper unit.
the cone is increased. Consequently, when the cone
The preferred embodiment of the loudspeaker of the
area is increased, so is the mass of the cone. This in
present
invention incorporates several unique‘ princi
30
crease in mass also prevents the cone from traveling
ples,
among
which are:
properly at the high frequencies of the audio band. The
I. The use of separate low and high frequency multi
driver arrays, which because of their design, overcome
answer to this problem could be simple; viz., separate
the audio band into two smaller bands of low and high
frequencies, each driving a separate woofer or tweeter,
respectively. However, the large woofer lacks adequate
the inherent resonance and phasing problems of loud
35
transient response in the low frequencies as well as any
frequency extending above that point. Although ef?
speakers.
2. The development of two separate and complemen
tary loudspeaker enclosures to exhibit full range capac
ity.
'
cient, it requires the use of an enclosure, which because
3. The use of a three-sided, semi-omnidirectional
of the interaction of the driver and the cabinet, is tuned
radiation
pattern, which effectively recreates realistic
40
to a particular frequency. This is done to increase the
overall bass output of the loudspeaker.
sound; panorama, while retaining excellent directional
’
ity.
Another method of obtaining large cone area is to
use the combined effect of several smaller woofers.
This offers several advantages, such as: several magnet
v
4. The use of a simpli?ed wiring terminal, which
allows for maximum ?exibility in hookup of the louds
unit, lighter cones for better transient response, and
peader for any required usage.
5. ‘The design of a commercial packaging arrange
each speaker receives less power and consequently
produces less distortion. The concept of multiple-driv
unsuitable environments, while retaining its excellent
assemblies (higher e?iciency) rather than one large
45
ment which allows the use of the loudspeaker in rugged
ers is not new, but because of the inherent phasing and
resonance problems of such arrays, their use has been 50
limited.
3. Prior Art
The bestprior art known to applicant from a search
in the U.S. Patent Of?ce files is listed below -
acoustic properties.
6. The use of a unique, consumer oriented construc
tion, to provide maximum ?exibility and acoustic per
formance through all embodiments including the lower
priced versions.
Instead of making some improvements in contempo
55 rary design, an ideal model of what a perfect loud
speaker should be was designed, and this was used for
a goal in the design of the loudspeaker of the present
invention.
Patentee
U.S. Pats.
Pat. No.
L. S. Doubt
J. E. Parker
.l. D. Hoffman
A. G. Bose
2,602,860
2,632,055
2,872,516
2,915,588
.
q
The ideal loudspeaker would have the following
lssue'Date
60 characteristics: It would have a frequency response that
M. L. Berry
3,052,758
July 8, I952
March l7, I953
February 3, I959
December 1, I959
September 4, I962
D. Manicri
A. G. Bose
3,241,631
3,582,553
March 22, I966
June 1, I971
K.'De Boer
F. W. Nichols
H. Ekdahl, et al.
D. Huszty, et al.
2,610,694
3,627,948
3,670,842
3,862,366
September I6, 1952
December 14, l97l
June 20, I972
,January 2], I975
overlapped'the input response of the ear; that is a re
sponse from about 10 Hz to about 25 kHz. It would
‘
‘
have this frequency response with minimal differences
in output. It would have proper acoustic coupling to the
65 room. It would be able to reproduce the natural rever
beration ?elds and sound panorama of live music. It
would have to have the dynamic range of live music
(120 db). ltstransient response would have to be per
4,031,318
3
4
greatly improves the acoustic appearance of the exist
fect. And ?nally, it would have to have resistance to
acoustic feedback.
The loudspeaker of the present invention was de
signed to come as close as possible to the perfonnance
ing crossover in the-other system;
' 3. Being separate allows for consumer ?exibility:
a. Unit may be purchased separately; and
of the ideal model, while still using driver components
b. Unit may be physically separated — increasing
that are readily available on the market. Thus the pre
sound panorama;
sent invention does not require the manufacture of any ,
'
.
specialized device but rather utilizes present technol
4. More drivers operating in the room with all the
advantages thereof — less distortion, more power han
ogy. The unit also has to have a maximum amount of
dling capacity, etc.;
?exibility, both in its ability to be used in any type of
application, and that the same design may be applied to
5. Upper section drivers (mid-range) need not be
anti-resonant decoupled because operating above reso
a lesser model and still maintain as many of the supe
nance point;
rior characteristics of the large model, yet offer an
economical compromise.
The present system achieves balanced quasi-omnidi
rectional radiation, such balance occuring through
equal energy radiation from each of the three operative
radiating planes of the loudspeaker, and on each such
plane equal attention is given to each band of the entire
frequency spectrum. This is achieved by an equal num
ber of speakers identically arrayed on each panel.
pendent full range system; and 7. If upper section is
used as a “full range” unit, it will suffer intermodula
tion distortion but this is reduced due to elimination of
low frequency.
-
BALANCED QUASI-OMNIDIRECTIONAL
RADIATION
20
The balanced, 3-dire'ctional system of the present
Although, broadly speaking, multi-driver speaker
invention involves:
1. Flat amplitude linearity — can be placed in corner;
systems, scattering resonances, accessory speaker en
closures, omnidirectional radiation pattern for comer
speaker placement, and built-in hinged sound re?ective
surfaces are individually known in loudspeaker designs
of the prior art, these concepts are uniquely applied in
_
6. Upper section can be used separately as an inde
25
2. No drivers on the rear panel — so no lost energy in
the comer;
‘
3. Use of 66% re?ective, 33% direct firing - most
closely recreates the reverberant fields of live music;
combination in the present invention as generally out
lined below.
4. Design allows the placement of the loudspeaker in
comer of room, the most ef?cient placement,‘ thus
‘
Multiple Drivers & Anti-Resonance Decoupling 30 requiring less amplifier power;
5.
The
most
effective
and
ef?cient
use
of
panel sur
In the present invention advantage is taken of having
face
area
to
mount
drivers;
and
independently different driver elements to individually
6. Speaker can be moved in and out from wall to
tune to a different resonant frequency achieved inter
a. Control amount of bass coupling; and
alia by:
'
b. Control amount of panorama (closer to comer, the
1. Different physical location in cabinet;
smaller it sounds, further from comer, the biggerit
2. Use of different lengths of tube behind the driver
component to individually tune the drivers to a differ
sounds).
'
‘
‘
ent resonant point;
BUILT-IN REFLECTOR SURFACES
3. The overall resonant frequency is the product of 40
In
the
present invention, the walls serve both as a
the drivers and its relationship to its enclosure; and
protective
casing when closed as well as diagonally
4. The resonance is scattered by using different mass
disposed re?ectivev surfaces when locked open, ‘the
cones;
which produce the following results:
re?ective surfaces on both sides serving to simulate a
‘
1. No overall resonant point in the low frequency 45
range allowing placement of cabinet in corner of room;
and
.
i
'
_
BRIEF DESCRIPTION OF THE DRAWINGS
,
For a further understanding of the nature and objects
of the present invention, reference should be ,had to the
2. This along with “phantom woofer effect" allows
the design of a system which is not resonant dependent
50
following detailed description, taken vin conjunction
with the accompanying drawings, in which like parts
a. Allows use of considerably lighter cones to get bass
response; and
are given like reference numerals and wherein:
FIG. 1 is an exploded, perspective view of the pre
b. Extends low frequency- to inaudibility because no
dependency upon a resonant point for bass response.
COMPLEMENTARY ENCLOSURES
In the present invention in the use of separate but
complementary enclosures, a three way system is used
‘.‘built-in comer".
$5
ferred embodiment of the complete loudspeaker of the
present invention, with the upper, mid-range cabinet
exploded up off the lower woofer-tweeter cabinet, and
with the center, front panel of each partially cut-away
to show the individual speaker structures of the panels.
,FIGS. 2A, 2B and 3A, 3B and 4A, 4B are front and
1. Operating the woofers and tweeters ‘as a 2-way 60 sides views, respectively, of the center panel, the left
side panel, and the right-side panel, respectively of the
system; and
with only one crossover point by:
'~
2. Operating the complementary mid-range at full
range with no crossover point with only the low fre
quency cut off by a capacitor;
'
producing the following advantages:
l. 3-way system with only one crossover point;
2. While one system is being crossed over, it is being ‘
complemented by one which has no crossover and
lower woofer-tweetercabinet of FIG. 1.
’
FIG. 5 is an isometric, partial view of the upper end
of the right-side panel (on its side) of FIG. 4A-4B.
FIG. 6 is a back view of the interior of the lower
woofer-tweeter cabinet of FIG. I, with the top, bottom
and back panels removed and the cabinet tilted for
wardly, showing the preferred embodiment of the stag
4,031,318
5
woofers of the present invention.
6
behind a particular speaker in a speci?ed series. The
pattern is outlined in FIG. 6. In viewing FIG. 6, the
gered, multi-length decoupling tube system for the
'
viewer is effectively standing behind the loudspeaker
FIG. 7 is a generalized, schematic illustration of the
preferred embodiment of the speaker hook-up of the
present invention for the lower, woofer-tweeter
cabinet with the back, bottom and top 104-106 re
moved and the side and front panels tilted forward to
speaker arrays, while FIGS. 7A-7C are schematic illus
trations of the external terminal strip of FIG. 7 but
further showing the external variations thereof for vari
ous types of amplification systems.
FIG. 8 is a generalized, schematic illustration of the
give a perspective view.
‘
In the preferred embodiment shown in FIG. 6, the
relative axial length of the‘decoupling tubes are illus
trated by dimensional number in the ?gure and are
summarized below in tabular form.
preferred embodiment of the speaker hook-up of the
present invention for the upper, mid-range speaker
Row
array.
FIG. 9 is a top perspective view of the back of the
lower speaker unit showing suitable rollers and handle 15
on the back of the unit for easy mobility and manipula
tion for a commercial embodiment of the preferred
embodiment of the system of the present invention.
FIG. 10 is a plan view of the lower speaker unit with ‘
a hinged, outer, protective case added to the cabinet 20
which can be folded out to a locked, diagonal dispo
sition to form a “built-in-comer” arrangement for the
Woofer No.
Tube No.
110
I14
llOa
ll4a
118a
Illa
ll5a
ll9a
ll2a
ll6a
120a
113a
ll7a
l2la
us
111
n5
n9
112
H6
120
113
in
m
Relative Length
loudspeaker, with some of the various beginning, in
terim and ?nal positions of the walls of the case phan
Thus for speaker pair set A, D the tubes run a relative
25
tom-lined in.
length
of 0-1-2-3-4-5, and the same for speaker pair
FIG. 11 is a graphical illustration contrasting the
set B, C. In the preferred embodiment shown the actual
complementary speaker out-put ranges of the 3-way
lengths of the tubes can be the relative length in inches,
system of the present invention with that of the other
thus tube 1100 can be two inches in actual length, etc.
speaker systems of the prior art.
DETAILED DESCRIPTION OF THE PREFERRED
30
This decoupling arrangement makes each driver op
erate as though it is enclosed in a separate enclosure.
preferred embodiment of the loudspeaker of the pre
This occurs because the air immediately behind each
driver is restricted (loaded) a different way by the
various length tubes. Due to the open end of the tube,
speaker units or enclosures, a lower or bottom unit 100
and an upper or top unit 200. The two speaker units
100, 200 include three operative sides — a front
net. l-Iowever, when one driver resonates, the other
eleven drivers are not in resonance, and therefore the
individual resonance effects are minimal. In effect, the
speaker panel 101, 201, ?anked by two side speaker
panels 102-103, 202-203, respectively, the exteriors of
the three speaker panels 101-103, 201-203 being sub
nant points and not their summation, or as compared to
EMBODIMENT
'
As best seen in the exploded view of FIG. 1, the
sent invention includes two, separate, complementary 35 an individual driver does operate into the entire cabi
system provides a minimal average of all twelve reso
the summation of twelve equal resonant points.
This arrangement allows the design of an enclosure
stantially identical. As will be explained in greater de
not speci?cally tuned to a particular frequency, and
tail below, the low and high frequency speaker arrays
consequently, subject to none of the problems of such
(woofers 110-121 and tweeters) are included in the
lower unit 100, while the mid-range frequency speaker 45 a tuned enclosure. It provides superior linear response
in the bass region without a resonant peak. Experi
array is included in the upper unit 200. To complete
ments have also indicated that critical adjustment of
the air-tight enclosures, each unit 100, 200 further of
tube length can be applied further to balance the inter
course includes back, bottom and top panels 104-106,
action of the individual drivers.
204-206, respectively, which do not include any
speaker elements.
50
The concept of staggering resonances to create an
The cabinet is constructed so that each side is identi
cal to the other from the line drawn horizontally
untuned enclosure is important in the present invention
through the panels. The speakers in row “A” (114, 110
response. Mechanical resonances can be further stag
& 1 18) have the same relative position in the cabinet as
gered by altering the. physical makeup of the driver
and can be applied further to approach a truly linear
the speakers in row “D” (117, 113 & 121), both being 55 itself. For example, within the same loudspeaker bas
at the extreme ends of the cabinet. The speakers in row
“B” (114, 111 & 119) are mirrors of row “C” (116,
112 & 120). Because these six speakers in row A and D
are in the same relative working position inside the
sealed air' column internal to the cabinet, they would 60
usually act in unison to resonate very close to the same
frequency. The speakers in row B and C would usually
do the same. Because of this decoupling of the two
ket, a heavier cone or heavier voice coil will produce a
heavier piston, thus lowering the resonant point. The
opposite is also true — a lighter cone or lighter voice
coil will produce a lighter piston and thus a higher
resonant point. By using several drivers with different
resonant points, the staggering effect is essentially the
same as the internal decoupling effect of the tubes, but
the use of the tubes represents the most preferred em
bodiment and is believed to be in itself inventive in the
pairs of six speakers is needed.
In order to accomplish this decoupling in the present 65 combination of the present invention.
invention, a series of tubes are arranged behind ?ve of
the six speakers in each pair, leaving one open. Each
tube in a pair set is a different length and is placed
Rather than use a large woofer in the preferred em
bodiment, a compromise was chosen between bass
output and mid-range transient properties of a smaller
7
4,031,318
8
environment and greatly improve the ?nal overall
sound product. Although the combined effect of the
woofer. Whereas an eight inch woofer lacks transience,
a 4 V2 inch woofer has adequate'transience but not
enough piston area (effective working cone area) for
smaller woofers to achieve a greater piston area, by
cabinet construction andits placement in the corner
o?'ers several distinct advantages, the design does not
require the cabinet being placed in the comer. It re
tains its excellent acoustic properties ‘regardless of
placement, however the comer represents its ideal
acting in unison as one loudspeaker. It is therefore not
environment.
full bass. A 6 % inch woofer was chosen as the pre
ferred embodiment for the woofers 110-121 which are
used in multiples. Multiple’ use allows the addition of
necessary in the present invention to use the large cone
.
The following is a summary of the external acoustic
mass traditionally needed for good acoustic imped
ance, and large bass output.
operation of the loudspeaker of the present invention
Besides the bottom unit 100, which contains the low
of air, partially trapped between sides 102, 202 and
103, 203 and their respective walls, the woofers
in its ideal environment. Because of the limited amount
and high frequency arrays, the preferred embodiment
of the loudspeaker of the present invention incorpo
114-117 and 118-121 on sides 102 and 103, respec
tively, are tightly coupled to the area on each side of
rates as well a separate full range, complementary en
closure 200, designed speci?cally for mid-range use.
the loudspeaker. It is this tight coupling and the capac
ity of the remaining front woofers 110-113, which
This separate enclosure also uses a multi-driver array,
210-213, 214-217, and 220-224 (the four mid-range
creates what'might be called a “phantom woofer”. It is
speakers on panel 203 not being visible in‘ the draw
so called because the air immediately surrounding the
ings) arranged on three identical panels 201-203, how 20 cabinet is so well coupled that it senses that it is being
ever it is operated full range with an internal low fre
acted upon by a woofer extending completely around
quency cut-off capacitor to eliminate the very low fre
the three radiating sides and the entire height of the
quencies. These low frequencies when reproduced
cabinet. It is this effect which provides the excellent
simultaneously with higher frequencies, produce inter
bass coupling to the room without large cone area and
modulation and Doppler distortion because of the large
25
mass conventionally required. The coupling effect also
cone excursions required. Because the unit is not re
provides other bene?ts as well. As can be'easily'visual
quired to produce bass transients, the cone size of the
drivers is reduced to for example 4 ‘A inches to improve
the midband transient response. The cabinet size is also
reduced to increase the cabinet loading on the drivers. 30
ized, the walls of the comer also provide the re?ecting
surfaces needed to achieve the natural reverberation of
live music. The sound radiating from sides 102, 202
and 103, 203 travels indirectly to the listener, ?rst
By lightening the cones, increasing cabinet loading,
being re?ected off the walls in the comer. It is this
and eliminating the low frequencies, the array 210+
will excel] in mid-range transience. This is precisely
where the lower unit 100 will have its poorest response,
effect, as well, which provides the expanded panorama
of the loudspeaker of the present invention. But be
cause of the limited amount of area the air is free to
as the woofers 110-121 are operating close to their 35 travel in, the loudspeaker still retains excellent direc
upper limit and the tweeters at their lowest limit. Un
tionality.
like all other louspeakers, the upper unit 200 is, not
design causes its crossover effect. By doing this, the
The mid-range speakers of the upper unit 200 com
plement the woofers and tweeters in the lower unit 100,
in a way substantially different from the prior art and
present invention has eliminated an extra crossover
giving the present invention very substantial advan
crossed over at each end of the band. The nature of its
point and greatly improved the overall appearance of
tages. These differences are graphically illustrated in
the crossover point in the lower unit 100.
Being a multi-driver array, the upper unit 200 is also
FIG. 11. With reference to FIG. 11':
subject to the previously discussed staggeringprinci
ples, but for somewhat different reasons. As the upper 45
unit 200 is operated above its resonant point, it is not ‘
necessary for internal anti-resonant decoupling. How
ever, by altering the weight of the pistons within a unit,
the linear midband response is greatly improved. This
~ .
Graph A represents a single, or multiple drivers,
operating over the entire frequency spectrum.
Graph‘B represents a 2-way system which applies the
audio ‘spectrum in bands to two different types of driv
ers, to wit, woofers (low frequency) and tweeters (high
frequency).
‘
_
Graph C represents a 3-way system incorporating an
occurs because each individual driver will operate 50 additional mid-range driver and corresponding cross
more ef?ciently and accurately at one particularfre
over point.
quency, while the remaining drivers each have their
Graph D represents the present invention which uti
ideal frequency within the band. They all work in uni- _
son, but each driver complements the other.
The upper unit 200 can be provided in four basic
models comprising 6, l2, 18 or 24 driver arrays which ‘
offer acoustic and economic ?exibility, the 12 driver
array being illustrated in FIG. 1. Acoustic performance
is improved several ways, as the number of drivers is
increased. Among those are reduced distortion, better
acoustic impedance to the surrounding air, better dis
persion, greater power handling capacity and more
possible staggering alternatives.
lizes a three way technique with only one crossover
point. The mid-range unit is rugged enough to operate
full range and complements the bottom unit 100 at its
most irregular point. The mid-range unit eliminates a
crossover point and greatly improves the acoustic ap
pearance of the existing crossover point in the bottom
unit 100.
60
J
The preferred embodiment of the loudspeaker of the
present invention incorporates a unique high frequency
array which exhibits excellent polar and dispersion
characteristics, without suffering from inherent phase
The loudspeaker of the present invention was speci?
problems. This is accomplished through the use of a
cally designed to be placed in a corner with thefront 65 soft, hemi-spherical dome transducer which radiates
panel 101, 201 facing outwardly with the back panel
180° on a plane. However, as can be visualized from
104, .204 facing the, apex of the wall corner. By doing
this, one is able to consistentlycontrol its ‘acoustic
FIG. 1, the array radiates from three sides 101-103,
providing dispersion of over 270°. And, because of the
9
4,031,318
This causes the problem of ringing in the ampli?er
bringing the ampli?er near oscillation. All of these
disadvantages each play a small part in the degradation
of the ?nal sound product.
from minimal phase disturbances. It is the semi-omnidi
rectional characteristics of the cabinet which also
lessen the unit’s susceptibility to acoustic feedback, as
the source device is not coupled to one, but several
drivers, each being a different distance from the
source.
10
ampli?er feel a reactive, rather than a resistive load.
arrangement of thetweeters, the loudspeaker suffers
> 2. Dual ended ampli?cation with crossover being
accomplished electronically before the ampli?ers is
'
Once again, it is the excellent acoustic design of the
loudspeaker which makes all of these advantages possi
ble, and not the physical placement of the speaker. The
accomplished as follows: The signal is processed full
range in the pre-ampli?er stages, but in an active cir
cuit placed directly before the power‘ amplifiers, the
signal is divided according to frequency content, and is
unit will provide superior performance, regardless of
placement.
sent individually to different ampli?ers, which in turn
drive the di?erent drivers. This offers several advan
minal strip and crossover components act as an inter
tages. There is no intermodulation distortion in the
face between the drive (ampli?er) and the load 5 ampli?ers due to the fact that the ampli?ers are not
(driver). The preferred embodiment of the loud
playing the same signal. Secondly, it is not necessary to
speaker of the present invention is designed so that the
use an extremely large ampli?er to avoid constant pre
loudspeaker has versatility and can be used without any
mature clipping. There are no phase or polar irregulari
modi?cations, in any possible type of application that I ties due to the fact that there is no brute force cross
20 over, and consequently, minimal phase shift. The disad
might be encountered.
There are several different ‘ways, generally speaking,
vantage to this method is that there is an extra ampli?er
Generally speaking, in a loudspeaker system the ter
to apply a drive to a loudspeaker. Each has its own
and an electronic crossover network required. The
second disadvantage, which is not the case with the
advantages and disadvantages. The following is a sum
mary of these methods and a demonstration ‘of why the
preferred embodiment of the loudspeaker system of the
present invention achieves versatility in its interface.
They are arranged from simple to complex.
25
preferred embodiment of the loudspeaker of the pre
sent invention, is that internal modi?cation is required
to separate the transducer channels and remove the
brute force crossover components. This is true in most
1. A single ended ampli?er, driving a brute force
?lter, placed between the drivers and ampli?er is the
other loudspeakers.
3. Dual ended bridged ampli?cation with crossover
most common type of crossover system. It is so because 30' being
accomplished electronically before the power
ampli?ers is the most sophisticated type of ampli?ca
it requires only one ampli?er and no type of specialized
electronics to cause the crossover to occur. lts advan
tion. It is essentially the same as that described in part
tage is therefore one of economics, and it operates in
the following manner: The full range of musical signals
2 supra, except that the grounds of the loudspeakers
need to be separated because there is no actual ground
for a particular channel is ampli?ed through a single 35 (both terminals are hot). it takes advantage of the 4X
channel of a power ampli?er unit and is delivered to
power factor of bridging. lts disadvantages are the same
the rear terminal of the loudspeaker unit. The signal is
as type 2 supra, plus it also needs to have its grounds
then divided according to frequency, with the low fre
separated.
quencies being sent to the woofers and the high fre
The criteria for the design of the interface of the
loudspeaker of the present invention was that it would
have to be as simple as possible, yet be able to be used
quencies being delivered to the tweeters. This is ac
complished by placing an inductor in series with the
woofer, and capacitor in series with the tweeter. The
effects of the inductor and the capacitor in relation to
speaker impedance are used to cause the crossover. As
this method does offer the advantage of simplicity, and
in any possible type of ampli?cation that might be
encountered. This is accomplished as follows: On the
45 bottom unit 100 a six-terminal strip 150 is used, and on
the upper unit 200 a three-terminal strip 250 is used;
thus a reduction in cost, it does cause some extreme
not FIGS. 7 and 8.
Pins 3 and 4 are the grounds for strip 150 and are tied
disadvantages. First, the power ampli?er is driven full
range, thereby setting up a condition that leads to gen
eration of intermodulation distortion. This is due to the
interaction of the highest and lowest frequencies mix
together by jumper‘ 34 for brute force use, note FIG.
50 7A. Pins 1 and 6 are the positive terminals of strip 150
to the respective driver components, and are also
ing in the same ampli?er. Also, due to the fact that the
low frequencies consume the largest amount of the
voltage swing of the ampli?er, an ampli?er of ex
shorted by jumper 16 for single ampli?er use. The
loudspeakers can be and preferably are delivered to the
user with these pins 3, 4 and 1, 6 jumped externally.
tremely high power output is required to reproduce
music of very wide range at a realistic listening level. A 55 If any of the other types of drivers are to be used,
these can be accomplished without any internal modi?
second set of problems arises at the crossover itself.
cation. ,By removing the jumper 16 from pins 1 and 6,
First is the phase shift which occurs as the natural reac
the positive terminals to both driver arrays have been
tion of the inductor and capacitor to different frequen
separated. By ‘hooking up the positive outputs from
cies. These phase shifts cause irregularities in both the
polar and'phase responses of the drivers, that is, at the
crossover point. The low and high frequency drivers
will be playing the same signal, but the phase shift in
60
the active components will cause them to be playing
the signals at different times. This causes cancellation
or aggravation of a particular frequency, dependent 65
upon the amount of the phase‘ shift.v The second half of
that same problem is that the crossover components,
because of their particular characteristics, make the
bi-arnpli?ers to pins 2 and 5, note FIGS. 7B and 7C, the
loudspeaker has been entered without going through
the inductor and capacitor crossover components. By
removing the jumper 34 from pins 3 and 4 the grounds
have been separated.
The system of the present invention can thus be used
with any type of ampli?cation, without any type of
internal modi?cation, merely be re-adjustment or elim
ination of the jumper cables 16, 34. A
11
4,031,318
Thus, as should be clear from the foregoing, the
lower and upper units 100, 200 are basically main
12
details herein are to be interpreted as illustrative and
not’ in a limiting sense.
frames each consisting of a top 106, 206, back 104,204
and botton 105, 205, making the “outside C”, as
viewed from the side. The remaining three sides 5
'
~
What is claimed as invention is:
1. A high ?delity loudspeaker system comprising:
an enclosed airtight speaker cabinet having three
operative panels each having openings therein into
101-103, 201-203 are completed by installing various
speaker array panels having the desired number of
the interior of said enclosure and speakers located
within said openings closing them off with the
backs of said speakers being exposed to said inter
ior through said openings, at least some of said
speakers having tubes surrounding them on their
speakers similarly arrayed about the three operative
sides. However, although the size (particularly the
height) of the panels 201-203 of the upper, mid-range
unit 200 can vary according to the number of speakers
200+ used, the size‘of the panels 101-103 preferably
remain the same, and vary only in speaker compliment.
back, interior sides extending into said interior, the
Because the alternate arrays for the lower unit 100
tially different, said tubes serving as anti-resonance
decoupling means for said speakers.
2. The high ?delity loudspeaker system of claim 1
lengths of at least some of said tubes being substan
having less than the number of speakers illustrated in
FIG. 1 are preferably designed asymmetrically, they
offer the added advantage of an alternate loading
scheme. For example, if only a total of six woofers were
used rather than the twelve illustrated, they would be
placed at the analogous locations of rows A and B; or if
only three woofers were to be used they would be
placed at the analogouslocations of row A. As can be
visualized, the cabinet 100 may then be placed either
up or down having the drivers either toward the ceiling
or ?oor. This will effectively decrease or increase the 25
bass coupling, depending on the desired effect.
The loudspeaker system of the present invention,
because of its high efficiency, excellent acoustic cou
wherein there is included at least two horizontal rows
of said speakers, at least two like speakers on each
panel, at least all of said like speakers except one hav
ing said tubes, no one of which has the same axial
length.
3. The high fidelity loudspeaker system of claim 2-in
which saidv tubes at least generally follow the relative
axial length ratio of 0-1-2-3-4-5.
.
4. The high ?delity loudspeaker system of claim
wherein a ?rst one of said rows includes the ratios vof
0-3-4 and the other row includes the ratios of 2-1-5.
5. The high ?delity loudspeaker system of claim 4
pling, high power-handling capacity and low distortion,
wherein the relative ratio length of the tubes on a panel
30
is ideally suited for commercial as well as consumer
occupies the same relative position in said two ratios,
high fidelity use. To accomodate these characteristics,
the tubes on one panel having the ratios “0” and “2”,
a unique commercial packaging arrangement can be
the tubes on second panel having the ratios of “3” and
employed.
“ l ”, and the tubes on the last panel having the ratios of
‘$5,’.
Such a commercial version, as illustrated in FIGS. 9 35 ‘64’,
and 10, can include bottom wheels or rollers‘ 50 and
6. The high ?delity loudspeaker system of claim 1
handles 51 for easy mobility and manipulation. And,
wherein said‘ three operative three panels are orthogo
because commercial applications are not usually suit
nally located with respect to one another and there "is
able environments, lower unit 100 of the loudspeaker
further included-orthogonally located back, top and
can incorporate a protective case made up of outer, 40 bottom panels which are completely closed and have
wooden wall sections 52, 53 and 54, 55. The wall sec
no operative speaker elements therein, all of said pan
tions 52, 53 (like 54, 55) are hinged together, with
section 52 (like 54) hinged to the back edge of the
els together forming a complete enclosure.
cabinet. The case opens and locks into place with each ’
wall 52, 53 and 54, 55 forming a straight, re?ective 45
surface forming a 45° angle with panels 102 and 103,
respectively, of the cabinet to provide the cabinet with
its own built-in “corner”. So even when taken out
doors, the cabinet can be provided with its ideal corner
environment. When closed the opposing wall sections 50
52 and 54 can be latched shut together.
The upper unit 200, because of its design, does not
offer alternate loading schemes. However, as this unit
may also be somewhat large, it can also be provided
with rollers and handles. it can incorporate as well the 55
same unique protective case described above, which
when open also provides a built-in corner for the unit.
For appearance or aesthetic purposes, speaker or
audio grill cloth of course can be used to cover the
exposed speaker panels 101-103, 201-203 illustrated
in FIG. 1.
The above are, of course, merely exemplary of the
possible changes or variations. Because many varying
and different embodiments may be made within the
scope of the inventive concept herein taught and be 65
cause many modi?cations may be made in the embodi
ments herein detailed in accordance with the descrip
tive requirements of the law, it'is understood that the
' I
7. A high ?delity loudspeaker system comprising:
a vertically extended speaker column having three,
vertical, operative speaker panels with speakers
therein and a fourth back panel; and
an outer, built-in protective casing for said three
'
panels comprising two hinged wall sections each
hinged to opposite side edges of said back panel
which when closed cover all three panels and when
open form two diagonally disposed sound re?ect
ing surfaces, providing the reflective acoustic ef
fect of said speaker column being located in a cor
ner.
‘
‘
8. A high ?delity loudspeaker system comprising:
a ?rst air-tight, closed cabinet having an array of
woofer and tweeter speakers contained therein for
reproducing low and high frequencies, respec
tively; and
‘
a second, air-tight, closed but complementary cabi
net physically separate from said ?rst cabinet hav
ing an array of mid-range speakers contained
therein for reproducing at least the mid-range fre
quencies, said two cabinets placeable together in
juxtaposition one ontop of the other, outside the
enclosure of the other; the speakers in both said
cabinets being driven to reproduce complementary
sounds.
~
'
‘
13
4,031,318
14
ing low, medium, and high frequency response respec
9. The high ?delity loudspeaker system of claim 8
square cross-section, three of the vertical panels form
tively, wherein said. woofers and tweeters include a
single frequency cross-over electronic circuit means
ing each said cabinets having speakers therein, the
other vertical panel and the top and bottom panels
having no operative speakers therein, said second,
to said tweeters, respectively, for the driving thereof,
wherein said cabinets each are box-shaped'having a
between them for feeding the low frequency signals
only to said woofers and the high frequency signals only
and wherein said mid-range speakers include no fre
quency cross-over means between them and said woof
ers and wherein tweeters, said mid-range speakers
being driven over at least substantially all of the full
complementary cabinet being located on top of said
?rst cabinet.
10. The high ?delity loudspeaker system of claim 9
wherein the speaker array on each operative panel in
each cabinet are substantially identical and arrayed on
each said operative panel in an identical pattern.
spectrum of audio frequencies, said woofers, tweeters
and mid-range speakers being generally simultaneously
driven to reproduce complementary sounds.
11. A high ?delity loudspeaker system comprising: an
array of woofer, mid-range and tweeter speakers, hav
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