null  null
United States Patent [191
1111
Shamma
[451 Nov. 12, 1974
SYSTEM FOR ELECTRONIC
[54]
3,359,433
3,397,286
MODIFICATION OF SOUND
[76]
Inventor: Ramzi A. Shamma, 610 W. 1 16th
St" New York’ NY" 10027
Filed;
Ju|y 2, 1973
[22]
12/1967
8/1968
3,848,092
Thauland ......................... .. 307/88.5
Prewitt et ali .................... .. 179/1 G
Primary E_\.aml-ner__Kmh|een H claffy
Assistant Examiner-Douglas W. Olms
Attorney, Agent, or Firm—Sandoe, Hopgood &
Calimafde
[21] Appl. No.: 375,366
Related US. Application Data
i571
ABSTRACT
[63]
Continuation-impart of sen No_ 191,632‘ OCL 32,
1971, abandoned, which is a continuation of Ser. No,
74,8.69, ‘Sept. 23, 1970. abandoned, which is a
Commu?llo" of Ser- NO- 7011987‘ Jan’ 31~ 1968,
abandoned
An audio ampli?er provides an output signal to drive
21 pair Of spaced loudspeakers. A signal distributor is
connected between the amplifier output and the loud
speakers and distributes the amplified audio signal in
different, varying proportions to the two speakers in
[52]
US‘ Cl‘ """"""" " 179/1 VI“ 179/] GP’ 84/127
is above the audio range and which is superimposed
[51]
[.58]
II.“- Cl ............................................. .. “04C 3/12
Field M Search -------- -- 179/1 G’ 1 GP’ 1 VLi
on the audio Signal recorded On the recording me_
dium. The apparent sound source is shifted back and
.
accordance with a control signal at a frequency which
179/1001 R; 84/125’ 1'27; 307/255;
forth between the speakers according to the prese
_.
lected pattern of the control signal to create a pleasur—
'
[56]
able listening experience for the listener. In an alter
Referenceslci‘ted
n?ite egi‘bo'dimieligt of thlc inventi‘pn, the oée'rall gainholf
UNITED STATES PATENTS
3
t e au 10 amp I ier IS a so vane in accor ance wit“ a
second control signal superimposed on the audio sig
nal at a frequency above the audio range to create a
lFieece ------------------------------- ,
,
-
3,056,854
ine ................................ ..
10/1962
Kutzenstein el al‘
_-
179” GP
3,272,906
9/1966
De Vries ct al ................ .. 84/125
3,281,784
10/1966
Farthing ............................ ,. 307/255
'
.
.
,
-_
-
3
mm"
1
8 Claims, 14 Drawing Figures
MANUAL.
M’,
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PRE-AMPuFiER.
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AalgzllglER C5
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FILTER
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_
FILTER
VOLUME O/r/
a F
,6,
1
w, W
aaie
I
SELECTOR.
,
1
F
1
_
FILTER
FD
4"
it?
c f1811-2 /
\
___
-
/
i
FILTER
C
AMPLIFIER
2m/§;
—‘———L_
SIGNAL
’ DISTRIBUTOR
$23133"
‘
F,
‘
MANUAL
206 gé'rtirnou.
4
/
~,_
:till different and pleasurable listening effect to the 11s
CONTROL
easiest“
?g
SIGNAL
a
LAMPLIFIER
DISTRIBUTOR
(era/re
SELECTOR
(_
Z”
”5/
“25:12am
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’”
3.848.092
PATENTEL, MW 1 21974
SHEEI 5 OF 6
-ETbaF
?mz/Ag?A/mm
INVEN OR
BY
.
A
ORNEY
3,848,092
1
2
SYSTEM ‘FOR ELECTRONIC MODIFICATION OF
-
cal signal distributor used in FIGS. 1 and 2 and seen in
detail in FIGS. 3A and 3B;
SOUND
- FIG. 9 is a chart of potential values at different points
This is continuation in part of co-pending application
in the circuit of FIG. 8 useful in explaining the opera
tion of the transistor distributor circuit shown therein;
Ser. No. 191,632, ?led Oct. 22, 1971 now abandoned,
which was a continuation of Ser. No. 74,869, ?led Sept.
23, 1970, now abandoned; which was a continuation of
Ser. No. 701,987, filed Jan. 31, 1968, now abandoned.
FIG. 10 illustrates an embodiment of the invention
particularly useful for individual musical instruments;
and
BACKGROUND OF THE INVENTION
1O
In the continuing development of sound systems in
recent years, considerable effort has been expended to
provide apparatus for improving the reproduction of
music and speech. However, these efforts have gener
ally been directed at improving ?delity so that the pro~
gram heard sounds as nearly as possible like the origi
nal “live” performance.
'
FIG. 11 is a schematic diagram of an alternative em
bodiment of the invention which further includes
means for varying the gain of the audio ampli?er in ac
cordance with a preselected pattern.
SUMMARY OF THE INVENTION
15
Briefly, this invention includes electronic ampli?er
means for amplifying a signal representative of music
or other type program material, a pair of loudspeakers
‘
I have discovered that by deliberately modifying the
spatially connected between the output of the ampli?er
original program material in a desired manner, an en
and the speakers, and means to control the distributor
in such a manner that the ampli?er output is fed to the
tirely new and pleasing type of sound reproduction is
produced by which an entirely new dimension in listen
speakers in different and varying proportions to pro
duce a novel and pleasing listening experience created
ing pleasure is experienced by' the listener.
It is an object of this invention to provide an entirely
by the illusion of a sound source shifting or ?oating
new type of pleasurable musical experience to the lis 25 back and forth between the speakers, the shifting and
tener.
?oating characteristics depending upon the particular
,
Another object is to provide a system in which re
corded conventional music can be modi?ed to present
the same music to a listener with an entirely different
control signal characteristics used to actuate the dis
dimension in sound.
Yet another object is to produce sound from a pair
-of speakers spaced apart from each other in such a
of the ampli?er output to the two speakers is controlled Y
tributor.
'
In one embodiment of the invention, the distribution
by' a manually operated signal generator, which con
trols the signal distributor. In this embodiment, the pro
manner that the sound appears to emanate from either ‘
gram material may be either “live“ or recorded. In an
speaker or to any apparent source between the speak
other embodiment, the program material is derived
ers and in such a manner that said source may shift 35 from a recording medium and the distributor is con
back and forth between the speakers.
To the accomplishment of the above and to such fur
ther objects as may hereinafter appear, the present in
trolled by a control signal which is recorded with the
program and which is separated from the program ma
ter'ial by a suitable signal separation circuit.
vention relates to a system for electronic modi?cation
together with the accompanying drawings in which:
DESCRIPTION OF PREFERRED EMBODIMENT
Referring now to FIG. 1, there is shown a system for
reproducing sound in accordance with one embodi
FIG. 1 is a block diagram illustrating a sound repro
duction system according to oneembodiment of this
ment of this invention, This system includes a source of
program material, which may be “live,” or may be a re
of sound, substantiall as de?ned in the appended claims
and as described in the followingspeci?cation taken
invention;
FIG. 2 is an illustrative schematic wiring diagram of
a portion of the system shown in FIG. 1;
FIGS. 3A and 3B show one embodiment of a signal
distributor which forms an integral part of this inven
45
cording such as the record 10, a signal generating de
vice such as a pickup 12, a preampli?er l4 and a power
ampli?er 16, all of which may be conventional compo
nents in this embodiment. The audio output signal from‘
the power ampli?er 16 is fed on a line 18 to a signal dis
tion, the same being connected in the circuit of FIG. 2;
tributor 24,.which distributes a portion of the audio sig
FIG. 4A illustratives a top view of one form of a
loudspeaker 28 spaced therefrom. The signal distribu
nal to a left loudspeaker 26 and a portion to a right
mechanism that may be used in conjunction with the . tor 24 is controlled by means of a control signal genera
circuit of FIG. 2 to generate a control signal;
tor 20, which develops a control signal that is ampli?ed
FIG. 4B is a side view of the mechanism of FIG. 4A, 55 by a control ampli?er 22 to a level suf?cient to operate
taken along the line 4B.—-4B thereof;
the distributor.
FIG. 5 shows in block diagram form another embodi
FIG. 2 shows a schematicwiring diagram of a portion
ment of this invention which employs a system similar
of the system of FIG. 1 which includes the control sig
to that of FIG. 1, but with a control signal selector for 60 nal generator 20, the control ampli?er 22, the signal
deriving the control signal from a recording medium;
distributor 24 and the speakers 26 and 28. The control
FIGS. 6A and 6B illustrate wave-form diagrams use
signal generator 20 may take several forms, one pre
ful in explaining the operation of the embodiment of
ferred form comprising a voltage divider, including a
the invention seen in FIGS.- 5 and 7;
fixed resistor 32 and a variable resistor 34, connected
FIG. 7 illustrates one form ofa control signal selector 65 to any suitable source of negative potential, such as a
circuit used in the system of FIG. 5;
10 volt D.C. source. This voltage divider provides a
FIG. 8 illustrates one fonn of a transistor distributor _ variable biasing potential at the junction 36 when the
resistor 34 is varied and this variable potential com
circuit which can be employed in lieu of the mechani
3,848,092
3
4
prises the control signal which actuates the signal dis
grasping the ?nger-engaging member 71; alternatively,
tributor 24.
This control signal is fed to the control ampli?er 22
which employs a pentode tube 38_having a control grid
hand may be placed over the lever 69 to rock the same
about the axis 70, to vary the resistance between the
38a for receiving the control signal from the junction
wires 35.
.
the member 71 may be eliminated and the palm of the
r
36 in the control signal generator 20. This tube 38 em
The bottom of the lever 69 is provided with track
ploys conventional circuitry and amplifies the control
signal at the junction 36, this ampli?ed signal then
forming members 72,, each having slots 73 therein.
being fed to the signal distributor 24.
Elongated rigid structural members 74 are arranged to
slide at their upper ends along their respective slots 73
The signal distributor 24, in the embodiment of the
invention shown in FIGS. 1 and 2, comprises a magneti
and are retained against falling out of their slots by suit
cally-actuated power distribution potentiometer in
75. The lower ends of the rigid members 74 are
cluding a coil 40 for actuating an armature 42 to cause
a contact 44 thereon to change position on a resistance
element 46. The left speaker 26 is connected by a wire
mounted for pivotal movement on sets‘ of apertured
48 to a contact 50 on one end of the resistance element
46-‘and the right speaker 28 is connected by another
wire 52 to a contact 54 on the other end of the resis
tance element. Further details of the signal distributor
able retaining means such as transverse end members
brackets 76 on‘ the base 65 by means of pins 77 con
nected to these members. Helical springs 78 are pro
vided at the pins 77 to provide damping and also to in
sure a given “at rest” position of the lever 69 and slid
ing contact 34b, as seen in solid lines in FIG. 48 when
no ?nger pressure is applied to the member 71 on the
24 are seen in FIGS. 3A and 33, to be-discussed herein 20 lever. If desired, this “at rest” position may be made
changeable by a spring adjustment, or by providing
after.
The signal distributor coil 40 is connected between
the plate 38b of the tube 38 and the potential supply
' lead 56. Accordingly, it will be appreciated that a varia
tion in the input signal to the tube 38 will vary the out 25
suitable means for setting the resistance element 34!) in
slightly different positions along the arcuate path of the
contact 34b.
Referrring now to FIGS. 1-4, the manner of opera
put therefrom and cause a commensurate movement of
the armature 42. This will move the Contact 44 on the
tion of the ?rst embodiment of this invention will be de
scribed with the record 10 having‘ music recorded
resistance element 46, causing an increase in the resis
thereon. When the record 10 is played, the preampli
fier 14 and the power ampli?er 16 will amplify the sig
nal generated by the pickup l2 and feed it to the signal
tance between ' the line 18 and one of the speakers
26-28 and a decrease in the resistance between the line
18 and the other speaker, thus changing the distribu
tion of energy to the speakers. Such changes, when of
distributor 24. With the armature 42 (FIGS. 2, 3A and
3B) in the center position shown, the resistance be
tween the sliding contact 44 and the one terminal 50 of
the proper timing and amplitude, will provide a listener
the resistance 46 will be equal to that between the
positioned at the location 30 between the two speakers,
with a very pleasing aural experience heretofore un 35 contact 44 and the other terminal 54. Accordingly, the
power fed from the line 18 through the armature to
known. Further description in this connection will be
each speaker 26 and 28 will beequal. Thus a person lis
given under the detailed description of operation be
tening at the location 30 will hear an equal volume of
low.
sound from each speaker and the location of the appar
FIGS. 3A and 3B show the mechanical details of the
ent sound source will be located midway between the
signal distributor 24 seen in FIG. 2. From these figures
speakers 26-28.
it will be seen that the basic electromagnetic unit,
In accordance with the first embodiment of this in
which includes the coil 40 and armature 42, is of the '
vention, however, the sound emanating from the speak
relay type, the coil 40 being wound on a soft iron core
ers 26-28 may be varied so that the volume of sound
41. The unit is‘ mounted on a base 58 with the coil 40
from the left speaker 26‘is ?rst decreased while that
positioned on a pedestal 60. The armature 42 is
from the right speaker 28 is increased and then vice
mounted on the base 58 for_side~to~side movement on
versa. During these changes the total sound output
a leaf spring 62, and for simplicity is shown in the cen
from the two speakers will remain substantially con
ter position in FIGS. 3A and 3B corresponding to that
stant. These changes are achieved by lowering and rais
_ seen in FIG. 2,.which corresponds to the zero signal
50
ing the lever 69 of the mechanism 66 seen in FIGS.'4A
bias condition on the control amplifier 22. At rest, the
and 4B, which is connected as a part of the control sig
armature contact 44 actually engages the contact 54.
nal generator 20 by the wires 35 to form the variable
The resistance element 46 is secured to a suitable
resistor 34. It will be clear that such motion of the lever
mounting bracket 64, affixed to the base 58 by a lower
69 of the mechanism 66 will vary the resistance be
portion 64a thereof.
55
tween the wires 35, thus changing the potential on the
FIGS. 4A and 4B show one form of a mechanism 66
junction 36 of FIG. 2 and causing the output of the tube
that may be employed as a part of the control signal
38 to vary, thereby varying the position of the distribu
generator 20 of FIGS. 1 and 2 and which includes the
tor armature 42. The movement of this armature 42
variable resistor 34 shown therein. This variable resis
tor 34 includes in FIGS. 4A and 4B, an arcuate shaped 60 will follow faithfully the excursions of the lever 69 of
the mechanism 66. Thus for each downward movement
resistance element 34a, mounted on one of a pair of
of the member 71 by the listener, as represented, for
brackets 67 on a base 65, in conjunction with a sliding
contact 3412, arranged to move over the surface of the
example, by the position of the lever 69 shown in
element 34a. The sliding contact 34b is ?xed to one end
dashed lines and indicated by the numeral 79, the ar
of an arm 68, which is ?xed to a lever 69 mounted for 65 mature 42 will move to the right and will increase the
volume from the right speaker 28 while decreasing the
pivotal movement on the brackets 67 about an axis 70.
The wires 35 comprise end leads for the variable resis
tor 34a, 34b. The lever 69 is operated manually by
volume from the left speaker 26. When the member 71
is raised, however, the reverse effect will be produced,
3,848,092
5
6
i.e., the volume ‘of the right speaker 28 will decrease
and that of the left speaker 26 will increase. The effect
as, for example, a music arranger. This is accomplished
as the arranger listens to the music being played and
may be achieved in a number of ways. One way is for
the musical arranger to operate a suitable electronic
of such volume increase and decrease in alternate
speakers is to create the very pleasant illusion of a
movable sound source shifting or “floating” back and
circuit so that a 30 khz continuous control signal is su
forth between the speakers 26-28, the particular char
perimposed on the music signal to be recorded. This 30
khz signal is modulated by the arranger in such a man
ner that when he wishes the music to play at equal vol
acteristics of these excursions depending upon‘ the pre
cise manner of operation of the lever 69. After a short
amount of experience, the listener-operator will be able
ume through the speakers 26-28 of FIG. 5, the level is
to cause the sound to “?oat" back and forth between
maintained at a given amplitude such as that indicated
by the waveform 102 of’FIG. 6A. When he wishes a
greater volume of sound to emanate from the left
the speakers in a very pleasant manner, the speed of the
excursion and the time period between excursions
being selected at will to blend the musical tempo to
speaker 26 and less volume from the right speaker 28,
the amplitude will be reduced below said given value,
gether with the listener’s mood and preference. When
the listener wishes to hear the music without these ef 15 as indicated by the waveform 101 of FIG. 6A.
fects, he simply takes his hand off the lever 69, thus al~
Thus it will be appreciated that the ‘arranger will
lowing the same to be returned to the “at rest” posi
tion, and the porgram will play exactly as it was re
cause the pre-recorded control signal on the record 10’
to be amplitude-modulated in accordance with his ex
corded with no motion of the apparent sound source
pert knowledge and taste in music in order to produce
20 the shifting or “?oating” effect of the sound source
located between the speakers.
FIG. 5 shows a sound system in accordance with a
back and forth between the speakers 26428 when the
second embodiment of the invention. It will be seen
music is reproducedthereby. Each of the wave F1 and
that this system is very similar to that of FIG. 1, but that
F2 of FIGS. 6A and 6B denote modulated control sig
a control signal selector 80 is provided in place of the
nals which produce such effect. The means for record
speci?c control signal generator 20 of FIG. 1 and re
ceives its input from a signal generator comprising the
record 10' and the pickup 12, through a lead 82. If de
25
ing these control signal waves F1 and F2 may comprise
a 30 khz signal source, a 40 khz signal source, and
means for modulating each of these signals frequencies
sired; the lead 82 could also be connected to the output
in accordance with the arranger’s preference. The ar—~
ranger’s modulation control may comprise a suitable
According to the embodiment of FIG. 5, the record 30 manual variable resistance control, such as that shown
of‘ the preampli?er 14.
‘
_ 10’ is different from the record 10 of FIG. 1. This re
cord 10’ contains a program source, such as music, and
' also a ?rst modulated control signal F 1 of an inaudible
in FIG. 4, for example.
'
‘
The modulated control signal F2 has different ampli
tude vs. time characteristics than the modulated con
frequency, such as the 30 khz signal seen in FIG. 6A,
trol signal Fl so that the listener, by means of the selec
and a second modulated control signal F2 of 40 khz, 35 tor switch 88 of FIG. 7, may choose between the musi
such as seen in FIG. 6B. These modulated control sig
cal program reproduced according to the control signal
nals are generated by the pickup 12 along with the re
corded music, the composite signal appearing on the
input lead 82 to the control signal selector 80.
Fl of FIG. 6A or the different program reproduced ac
cording to the control signal F2 of FIG. 6B. The music
may also be played in the natural recorded mode by se
lecting the No. 3 switch position so that neither control
FIG. 7_ shows one form of a circuit that can be em
ployed as the control signal selector 80 to extract the
‘?rst and second control signal frequencies F1 and F2
from the composite signal on the lead 82. This circuit
comprises a ?rst parallel resonant circuit, including an
inductance >84 and a ?rst capacitor 86, which is tuned
to the F1 control signal frequency of 30 khz. A selector
signal is selected, in which case ordinary high ?delity
reproduction results.
The embodiment of FIG. 5 operates in the manner‘
now to be described. As the record 10' is played, the
pickup 12 develops a composite signal comprising the
recorded music signal and the modulated control sig
switch 88 is provided to select the 30 khz frequency sig
nal when in position No. 1, and the 40 khz signal when
in position No. 2. This second position places the in
nals F1 and F2 of FIGS. 6A and 68 respectively. This
composite signal is ampli?ed by the preampli?er l4
and the power ampli?er 16 and carried on the lead 18
to the signal distributor for distribution to the speakers
. ,ductance 84 in parallel with a second capacitor 90 to
form a parallel resonant circuit tuned to the F2 control
signal frequency of 40 khz. When in position No. 3, nei~
ther signal frequency is selected.
A detector diode 92 is provided in combination with
a load resistor 94 and a capacitor 96 to demodulate
whichever of the signals F1 or F2 that is selected, to de
velop an output control signal. This control signal is
26 and 28. The control signals F1 and F2, however, are
not heard in the speakers because they are above the
55
range of audibility.
The composite signal from the pickup 12 also ap
pears on the lead 82 and is fed to the input of the con
trol signal selector 80. From the details of FIG. 7 and
the foregoing description, it will be appreciated that
present on the lead 98 and is fed to the grid 38a of the
when the switch 88 is in the No. 1 position, the parallel
60 LC circuit comprising the inductor 84 and capacitor 86
will be tuned to the 30 khz control signal F1. This fre
Unlike the embodiment of the invention shown in
quency will therefore be selected from the composite
FIG. 1, which is operated manually, the embodiment
signal on the lead 82, while the 40 khz control signal F2
seen in FIG. 5 operates automatically in accordance
and the music signal will be rejected. The control signal
with variations in the inaudible modulated control sig
F1 will therefore by demodulated by the diode 92, so
control ampli?er 22 of FIG. 2, which is also employed
in the systemof FIG. 5.
nals F1 and F2 recorded in the sound track of the re
cord 10’. These control signals are pre-recorded in ac
cordance with the selection of a musical expert, such
that the modulation information on the control signal
F1 is developed across the load resistor 94. This consti
tutes the control signal information and is indicated by
3,848,092
7
8
the upper envelope curve 105 of the F1 wave in FIG.
appreciated from FIG. 6B that the apparent music
6A. This control signal information potential 105 ap
pearson the lead 98 and controls the conductivity, and
speakers 26—28 by the control signal F2 during the pe
therfore the output of the control ampli?er 22. This
control ampli?er 22 and the signal distributor 24 func
tion as described in connection with FIGS. 1 and 2
above.
Referring further to FIGS. 6A and 68, it will be ap
preciated that when the control signal F1 has an ampli
tude modulation indicated by the height of the signal
102, the signal potential 105 across the resistor 94 of
source will be shifted back and forth between the
riod to’ - t4’. Between t4’ and 15’ however, the music will
emanate with equal volume from each speaker 26—28,
and will then abruptly emanate chiefly from the left
speaker 26, causing the apparent source to shift from
the center toward this left speaker. Between the time
period [5 — t6’ this unequal power distribution to the two
speakers will remain constant, and will then at time [6’
again change so that both speakers 26—28 again receive
FIG. 7 has a given “center” value, causing the control
amplifier 22 to “center” the signal distributor 24 so as
to feed equal power to each of the speakers 26—28. Ac
equal power, until time 17’. At time 17’ the apparent
cordingly, the sound source will appear to the listener
so maintained until time [8’, the apparent source will
shift from the extreme right to the extreme left and re
at the position 30 to exist midway between the speakers
26—28. This is the condition at the time to in FIG. 6A.
Between the times to and t1, however, the signal poten
sound source will shift to the right, since more power
is then distributed to the right speaker 28, and will be
38a of the tube 38, see FIG. 2. This will cause an in
main there until time 19'. From 19’ to 111’, the “swing
ing" or “floating” shift that occurred from time 1,,’ to
I,’ will again be produced. Then from time In’ 4 112’ this
shift will gradually become more rapid, while also shift
ing progressively less with each shift, until at time tn’
crease in the plate current of the tube 38, attracting the
the shift is zero and once again each speaker emanates
tial 105 across the load resistor 94 will become more
positive, thus decreasing the negative bias on the grid
signal distributor armature 42 closer to the coil 40 so
that more power is fed to the left speaker 26 and less
equal sound, placing the apparent sound source cen
to the-right speaker 28. As this is a progressive process 25
trally between the speakers 26—28. The “?oating” and
shifting phenomena of the location of the apparent
whereby the signal distributor follows the changes in
signal potential 105 of FIG. 6A, the apparent music
duces on the listener an entirely new dimension in the
source between the speakers 26—28 appears to shift
pleasurable experience of listening to music. It will be
source between the speakers 26—28 thus achieved pro
appreciated that an in?nite number of different time
From the foregoing, it will therefore be seen that the 30 and amplitude combinations can be employed for the
control signals to produce commensurate variations in
apparent music source will shift back to the center po
from the right soeaker 28 toward the left speaker 26.
sition between the time period t, — t2 and will then con
the reproduced music.
tinue toward the right speaker 28 during the time pe~
FIG. 8 shows a modification of the invention wherein
a transistorized signal distributor 24' is employed in
lieu of the mechanical signal distributor 24 described
earlier, and which also employs a transistorized control
amplifier 22' in lieu of the control ampli?er 22. The
control ampli?er 22’ comprises an NPN transistor 112
riod t2 - t3 as the potential 105 drops below the ampli
tude of the waveform 102. This process will continue
as long as the signal waveform 105 varies, as seen in
FIG. 6A.
The rate of change of the movement of the apparent
music source between the speakers 26—28 will, of
course, vary depending upon the rate of change of the
signal potential 105. Thus the shifting will be at similar
having emitter, base and collector electrodes 112e, ~
112b and 1120, respectively. A bias network is pro
recurring intervals between the time period t0 — t5,
when the shift will then become more gradual between
vided for the base 112b and includes a variable resistor
114 and a ?xed resistor 1 16. The junction 115 between
these resistors is connected by the lead 98 to the con
the period is — 110. Between the period [10 — t“, a recur
trol, signal selector 80 of FIG. 5 to receive the output
rence of the shifting frequency of the period to — t5 will 45 therefrom. When used with the embodiment of FIGS.
1 and 2, however, the series circuit comprising the re—
occur and from the period tl1 — :12 a gradual shift will
again occur, with the volume from each speaker 26—28
sistors 114 and 116 is replaced by the control signal
the same at time 112 so that the apparent source seems
generator 20 and no lead such as 98 is used.
to be located midway between the speakers. '
FIG. 6B shows details of the control signal F2 which
controls the same'basic music program as that con‘
trolled by the signal F1 but in a different manner. This
control signal F2 will control the operation of the signal
The control ampli?er 22’ further includes a resistor
118 connected to the emitter 112e with a by-pass ca
pacitor 120. A collector load resistor 122 is connected
between the collector electrode 112c and ground. Op
erating potentials for the transistor 112 are provided by
distributor 24 when the selector switch 88 of FIG.' 7v is 55 a suitable power source 124.
The signal distributor 24' includes a PNP transistor '
in the No. 2 position, since the 40 khz parallel resonant
circuit comprising the inductor 84 and capacitor 90
will then be operatively connected. Thus, simply by
turning the selector switch 88 from position No. l to
position No. 2, the listener will be able to enjoy the
same basic music on the record 10’, but shifted be
tween the speakers 26—28 in an entirely different man
ner in accordance with the control signal F2.
126 having emitter base and collector electrodes 1266,
126b and 1260, respectively, and also an NPN transis
tor 128 having emitter base'and collector electrodes
128e, 128b, 128a, respectively. An emitter resistor 130
is connected to the emitter 128 and an emitter resistor
131 is connected to the emitter 1262. The emitter resis~
tors 130 and 131 are preferably of equal value, but
The control signal F2 may be used to reproduce the
their speci?c values will depend upon the characteris
same basic musical program in a slightly different man
ner, or in an entirely different manner, depending upon
the nature of the music and the differences in the char
tics of the transistors 126 and 128. Another emitter re
sistor 132 is connected in series with the emitter resis
acteristics between the ?rst control signal F2. It will be
ing potential source 133 to establish a proper bias on
tor 131 to ground. The resistor 132 is bridged by a bias
9
3,848,092
10
the transistor 126, as will be more fully appreciated
tial on the transistor 126 in a more negative direction
later. A transformer 134 is provided having its primary
so that it has changed from the value +4 volts to +2
136 connector between the collector 1280 and a suit
speaker 28. Another transformer 140 is provided-with
volts as seen in the chart of FIG. 9. When the emitter~
base voltage on the PNP-transistor 126 is made more
negative, the control current increases so that the left
a primary 142 connected between the collector 126C
and another suitable power source 144 to provide
also be apparent that any ‘change in the voltage drop
able power source 138 to provide power to the right
speaker 26 now receivesmore power. However, it will
power to the left speaker 26. The signal distributor 24
also includes an input transformer 146 having a pri
mary winding 148 for coupling power from the power
ampli?er 16 to the distributor circuit. The secondary
across the resistor 122 will not only increase the con
ductivity of one of the transistor 126 and 128, but will
also decrease the conductivity of the other transistor,
since the resistor 122 is in series with the base-emitter
circuit of each transistor. Thus, when the potential
150 of the transformer 146 has one end connected to
each of the transistor base electrodes 126b and 128)).
The other end of the secondary 150 is connected in se
ries with the control ampli?er load resistor 122 to
across the load resistor 122 increased to 5 volts, caus
ing the base-emitter voltage of the transistor 126 to
shift from +4 volts to +2 volts, it also caused the base
emitter voltage of the transistor 128 to shift from —4
ground.
With such a circuit as in FIG. 8 it will be clear that
volts to —6 volts. Since the transistor 128 is an NPN
the collector load resistor 122 of the control ampli?er
22’ is in series in the emitter-base path of both the tran
sistors 126 and 128. Also, the polarities of the voltage
drop across the load resistor 122, the emitter transistor
transistor, this more negative shift in bias decreases the
collector current, so that less power is now transmitted
indicated in the drawing. Thus it will seem that in the
from the transformer 146 through the transistor 128 to
the right speaker 28. Thus, it will seem that the shift of
the apparent signal source between the speakers 26 and
28 is achieved by appropriate bias change on the tran
emitter-base path of the transistor 128 the potentials
sistors 126 and 128 resulting from the voltage drop
130 and also the emitter resistors 131 and 132 are as
across the resistors 130 and 122 are in series adding re 25 change across the load resistor 122 caused by the
lationship, and also that in the emitter-base circuit of
the transistor 126 the potentials across the resistors
131, 132 and the resistor 122 are in series opposing re
lationship. Furthermore, the resistors 130 and 131 are
preferably of equal value for best performance of the
circuit. Still further, the resistor 132 and power source
133 combination is selected so that the total voltage
drop between the emitter 126e and the'base l26b has
a value equal to that between the emitter l28e and the
change in the control signal potential on the lead 98.
The circuit of FIG. 8 will operate in the reverse man
ner to that just described to shift the position of the ap
parent sound source between the speakers from either
the middle position toward the right speaker or from a
left posiiton toward the right speaker. Thus, let us con
sider again the situation when the load resistor 122
would have a voltage drop of 3 volts, so that the transis
tors 126 and 128 would be biased to +4 volts and —4
base 128]; for the “equal power” condition, i.e., thev 35 volts, respectively, as seen in the chart of FIG. 9. Then
condition under which each of the transistors 126 and
with a negative direction change in the control signal
1278 is biased exactly the'same so that equal power is
potential on the lead 98, the collector current through
passed by each of the transistors to their respective
the load resistor 112 will be decreased, causing a
speakers 26 and 28.
smaller voltage drop across the same, such as, for ex
Reference to FIG. 9 will help to illustrate this “equal
power” condition and the operation of the circuit of
FIG. 8. In the chart of FIG. 9, the “equal power" condi
tion exists when the voltage drop across the load resis
ample, 1 volt as seen in FIG. 9. This will change the
base-emitter voltage on the transistor 128 from —4
volts to —2 volts, as seen in the chart. This less negative
tor 122 of the control ampli?er 22' is 3 volts, at which
time the base-emitter voltage is +4 volts on the transis
rent of the transistor 128, thus increasing the audio
power transfer from the transformer 146 to the right
loudspeaker 28. As before, it will be clear that the po
bias change will cause an increase in the collector cur
tor 126 and —4 volts on the transistor 128. This corre
sponds to‘ a control signal level from the control signal
generator 20 of FIG. 2 or the control signal selector 80
of FIG. 5, which is intended to cause the signal distribu
tor 24’ to pass equal power to each of the speakers 26
tential change on the load resistor to I volt will also re
sult in an increase in the positive base-emitter potential
on the transistor 126 to +6 volts, thus decreasing its‘
conductivity and the output from the left speaker 26.
Thus the position of the apparent sound source be-
and 28. For this condition, the apparent sound source
will,-of course, be located midway betweenthe speak
tween the speakers 26 and 28 has now been shifted to
ers.
ward the right speakenThis process will continue in
When, however, it is intended to shift the apparent
source toward the left speaker 26, the audio-power
transmitted from the transformer 146 through the left
55
speaker transistor 126 will be increased due to an ap
propriate change in the bias potential current in the
base-emitter circuit 126b-126e. This is achieved by a 60
de?nitely in accordance with 'the variations in the con
trol signal applied to the control ampli?er 22’. Pre
operation compensation for room acoustics and for
variations in ampli?cation differences in the left and
right transistors 126 and 128 is provided by an initial
setting of the variable resistor 114 until the desired bal
positive direction change in the control signal potential
ance is achieved between the speakers 26 and 28. If the
on the lead 98 of FIG. 8 of such a value as to increase
control signal generator of FIG. 2 is used, the resistor
32 may be made variable to provide the pre-operation
balance.
Although this invention has thus far been described
the collector current from the collector electrode 1220
through the load resistor 122. This condition is repre
' sented in the chart of FIG. 9 wherein it is indicated that
the voltage drop across the load resistor 122has now
increased from 3 volts to 5 volts. This voltage drop
change will, of course, change the base-emitter poten
in connection with a recorded program in the embodi
ments of FIGS. 1 and 5, it is also applicable for use with
“live” music. One example of such use is shown in
3,848,092
11
.
12
.
the art are aware, such an instrument carries a sound
where it is ampli?ed and applied to the input'of audio
amplifier 172. The output of ampli?er 172 is applied to
the input of a signal distributor 176, which operates in
pickup device such as a microphone 126 and this may
the manner described hereinabove with respect to the
be used to generate the electric signal corresponding to
the music in place of the pickup 12 of FIG. 1, which is
previously illustrated embodiments, to varyv the distri
bution of the audio output to a pair of loudspeakers
178 and 180 in accordance with the amplitude pattern
of a distribution control signal applied to the distributor
FIG. 10 in which the basic system of FIG. 1 is employed
with an electric guitar 160. As those knowledgeable in
then fed to the preamplifier 14. In accordance with the
embodiment of the invention seen in FIG. 10, the guitar
160 also carries on the back side thereofa manually op
erable device 66’ of the type illustrated as the device
at a line 182.
66 except that the lever 69 of FIGS. 4A and 4B is re—
The output of recording medium 170 which includes,
in addition to the audio signal, the superimposed vol
ume and distribution control signals, is applied to the
input of narrow-band-pass ?lters 184 and 186 which
are tuned respectively to pass only the volume control
placed by an elongated plate 164 in FIG. 10. This plate
signals at frequencies FA and F8. Similarly, the signal
164 is mounted to pivot about the point 168 and is of
from medium 170 is applied to the input of narrow
band-pass ?lters 188 and 190 which are tuned respec
tively to pass only the distribution control signals at fre
66 seen in FIGS. 4A, 4B and described above in con
‘ nection with the ?rst embodiment. The device 66’ is
similar in all respects to the manually operable device
curved cross section, as seen, to accommodate opera
tion by the palm of the hand.
quencies FC and FD.
This mechanism 66’ is connected by means of the
wires 35 to the control signal generator 20 to form a 20 The outputs of ?lters 184 and 186 are applied to the
part thereof and when operated produces a control sig
nal for varying the distribution of the musical output
from the speakers 26 and 28 in the manner already de
input of a volume control selector 192, which consists
essentially of a selector switch SW-l having a movable
contact which can be manually positioned at either
contact A or B. The ?xed contact of switch SW-lv is
scribed. Thus it will be seen that with the arrangement
of FIG. 10 the guitar player may add an entirely new 25 connected to the input of a volume control ampli?er
194 which ampli?es the volume control signal selected
dimension to the music from the speakers 26-28. With
by the operation of the switch. The thus ampli?ed sig
this embodiment it will be seen that it is possible to vary
nal is applied to the gain control input of audio ampli
the musical distribution between the speakers 26-28 in
fier 172 at a line 196. The varying voltage of the vol
a manner particularly suitable for the type of music and
ume control signal at line 196 varies the gain of audio
the moods of the player and the audience, since the
amplifier 172 in correspondence to the amplitude pat
control device 66' is mounted on the instrument 160
tern of the volume control signal in any of several man
and controlled by the person playing it at the time it is
being played. It will be apparent that the embodiment
ners, all of which are conventional per se, and are
therefore not further described herein.
of FIG. 10 can be employed with musical instruments
35
The outputs of ?lters 188 and 190 are applied to the
of different types.
inputs of a distributor control signal selector 198 con
In the embodiment of the invention illustrated in
sisting essentially of a selector switch SW-2, which is
preferably ganged, as indicated by the broken line con
nection 200, to volume control signal selector switch,
speakers is varied according to a predetermined, but
SW-l.
yet 'arbitrary pattern. This combined variation of the
The ?xed contact of signal selector 198 is applied to
signal strength as well as the signal distribution between
a distribution control signal ampli?er 202. The output
the speakers provides a listening effect that is unique
of ampli?er 202 is the distribution control signalat line
and far different than the one achieved by varying the
182 which is applied to signal distributor 176 to control
signal strength or distribution alone.
,
'
To this end, the audio signal recorded on a recording 45 the distribution of the sound between speakers 178 and
180 in the manner described previously.
'
medium 170 includes at'least two control signals super
In the operation of the sound system of FIG. 11, the
imposed on the audio signal. The control signals are at
listener selects one of the two available positions for
. different frequencies both of which are above the audio
the selector switches SW-l and SW-2. The audio out_
range. One of these control signals is employed as pre
put of ‘loudspeakers 178 and 180 is continuously shifted
viously described to vary the distribution of the ampli
between the speakers in accordance with the pattern
fied audio signal between the two loudspeakers. The
established by- the distributor control signal at line 182
other control signal is employed, as will be described,
while at the same time the volume of the total audio sig
to vary the overall amplitude of the distributed audio
signal by, as herein shown, varying the gain of the audio 55 nal applied to the signal distributor 176 varies accord
ing to a second random pattern corresponding to the
amplifier 172.
I
volume control signal applied to the gain control input
As in the previously described embodiment of the in
of the audio ampli?er. The overall effect achieved by
vention, the volume control and distribution control
this simultaneous dual variation of the audio signal is
signals may each include at least two signals each of a
more interesting and offers a greater variety of listening
different frequency above the audio range. Frequency
experience than that achieved by the use of either the
responsive means are provided to enable the listener to
volume or distribution control signal separately.
select one of the available matching pair of volume and
To permit an even greater variety of sound, addi
distribution signals. '
tional gain and balance controls may, as shown in FIG.
As shown in FIG. 11, the volume control signals are
at super-audio frequencies FA and F8, whereas the dis 65 11, be incorporated in certain elements of the system.
Thus, as shown, audio ampli?er 172 includes an addi
‘ tribution control signals are at different super-audio
tional manual gain control 204 as do volume control
frequencies FC and FD. The output of recording me
signal ampli?er 194 as indicated at 206, and distributor
dium 170 is applied to the input of a preampli?er 174
FIG. 11, the overall strength of the audio signal as well
as the distribution of that signal between the two. loud
13
3,848,092
14
control signal ampli?er 198 as indicated at 208. In ad
dition, signal distributor 176 may include a manual bal
control signals to said signal distributing means, said
signal distributing means further including means for
selectively applying only one of said first and second
control signals to said amplitude decreasing and in
creasing means, said signal distributing means being rc
ance control 210, such as that found on a conventional
stereo ampli?er, to enable the listener to preset the
audio distribution between the speakers. By manually
setting manual gain and balance controls 204-210 to
sponsive to the amplitude of said one of said control
signals to vary the relative amplitudes of said parts of
said output signal in accordance with the varying am
plitude patterns of said one of said control signals,
whereby a controlled shifting movement of the appar
different settings, the listener can determine the set
tings for these controls that are best suited for his lis
tening purposes, taking into consideration, for exam
ple, the listening conditions in the surroundings of the
system.
ent sound between said ?rst and second speakers is cre
ated.
Although the basic system of this invention has been
described in connection with vacuum tube circuitry, it
2. The system of claim 1, in which said actuating
will be appreciated that transistors may be employed
means includes a coil coupled to the output of said con
throughout the system. Also, although in connection
trol ampli?er, and said signal increasing means com
prises a resistor coupled in series between said first and
second speakers, and a slide arm magnetically coupled
with the embodiment of FIG. 5, a speci?c signal selec
tor has been illustrated as seen in FIG. 7, other arrange
ments may also be employed. Furthermore, tape or
other recording media may also be used inlieu of a re
to said coil and electrically connected to the output of
said audio signal amplifying means for movement along
cord. Still further, when tape is used, separate tracks 20 said resistor in response to the amplitude of said ?rst
may be used for the control signals F1 and F2 and these
control signal.
'
may be on tracks isolated from the track containing the
3. A sound reproduction system comprising a pro
program material. Furthermore, the speakers need not
gram source for providing an audio signal and first and
necessarily be positioned to the left and right of the lis
second control signals at ?rst and second frequencies
tener, as the unique effects of this invention can also be 25 above the audio range and superimposed on said signal,
utilized with one speaker above, and one below, the lis
an audio ampli?er operatively connected to said
tener. Also one speaker could be positioned close to
source, ?rst and second sound transducers, signal dis
the listener and one remote from him.
tributing means operatively connected to said audio
While the foregoing description sets forth the princi
amplifier and to said first and second transducers for
ples of the invention in connection with several specifi
selectively providing ?rst and second portions of said
cally described embodiments, it is to be understood
audio signal to said ?rst and second transducers respec
' that the description is made only by way of example
tively, means operatively connected to said source and
and not as a limitation of the scope of the invention.
said audio ampli?er for varying the gain of said audio
1 claim:
1. A system for modifying a sound program compris
ing means for providing an audio signal; means for am
plifying said audiosignal and presenting the same as an
35
ampli?er in accordance with one of said control sig—
nals, and means coupled to said source and said signal
distributing means for varying the relative amplitude of
said ?rst and second portions of said audio signal in ac
cordance with the other of said control signals.
4. The sound reproduction system of claim 3, in
a into two parts; a ?rst speaker connected to said signal
which said source further includes third and fourth sig
distributing means for receiving one of said output sig
nals at frequencies above the audio range superim
nal parts; a second speaker spaced from said ?rst
posed
on said audio signals, ?rst select means for apply~
speaker and connected to said signal distributing means
ing one of said ?rst and third control signals to said
for receiving the other of said output signal parts, said
signal distributing means including means for increas 45 audio ampli?er to vary the gain thereof, and second se~
lect means for applying one of said second and fourth
ing the relative amplitude of one of said parts while de
control signals to said signal distributing means to vary
creasing the relative amplitude of the other of said
the relative amplitudes of said ?rst and second audio
parts; said audio signal providing means comprising a
output signal; signal distributing means connected to
said amplifying means for dividing said output signal
- ‘recording medium having a program signal within the
audio frequency range and a ?rst control signal having
a ?rst frequency outside of the audio frequency-range
and having a ?rst preselected and varying amplitude
signal portions.
5. The sound reproduction system of claim 4, in
which said ?rst select means comprises ?rst and second
?lters for passing signals at the frequencies of said ?rst
and third control signals respectively, and first switch
bution of said output signal between said speakers, and 55 means operatively connected between the outputs of
said ?rst and second ?lters and said audio ampli?er,
a second control signal at a second frequency outside
said second select means including third and fourth ?l
the audio frequency range and different than said first
ters for passing signals at the frequencies of said second
frequency and having a second preselected and varying
and fourth control signals respectively, and further
amplitude pattern different than that of said ?rst con
comprising second switch means operatively connected
trol signal and corresponding to a second desired rela
between the output of said third and fourth ?lters and
tive distribution of said output signal between said
said signal distributing means.
speakers, said ?rst and second control signals being su
6. The sound reproduction system of claim 5, further
perimposed on said program signal and recorded on a
comprising a ?rst control signal ampli?er operatively
common recording path on said recording medium as
connected between said ?rst switch means and said
said program signal; and means operatively interposed
audio ampli?er and comprising ?rst manual gain con
between said recording medium and said signal distrib
trol means, and a second control signal ampli?er opera
uting means for separating said ?rst and second control
signals from said program signal and for coupling said
tively connected between said second switch means
pattern corresponding to a ?rst desired relative distri
3,848,092
15
'
v
and said signal distributing means and including second
manual gain control means.
'
-
l6
_
which said signal distributing means includes ‘manual
7. The sound reproduction system of claim 6, in
which said signal distributing means includes manually
controlled balance control means.
'
8. The sound reproduction system of claim 3, in
balance control means, and said audio ampli?er in
cludes manual gain control means.
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