Note: Descriptions are shown in the official language in which they were submitted.
J~ ,.3
PICK-UP F(:)R ~ E~ECTRIC~ MUSICAL X~lSTP~UM.E~ilT
OF TE~E STRIMGED TYPE
_ _
~r ~
The pre~;en~ ins7entiorl relate~ tcs a pick-
up :for an electrical rausic::al illstrumen~ of the
stringed type and, more particularly, to a pick~up
~or an electrlcal mu~ical in~trumerlt o the ~tringed
type which will enhanGQ khe bas~ fre~uency charac-
10 teri~tic~ of such in~trument.
BACKG~OU~D OF THE PRIOR ART
The pre~:;ent inven~ion relat~ roadly
~o elec:trical mu~ical in~txument~ o the stringed
typeu It i~ parkicularly applicable to arl elec-
15 trlcal bas~ ar or ~lm:Llar mu~ical islstrumellk
havi~g a plurali ~y s:~f stxetched strings exten~llng
acxoe~ a bvdy and a neck, betweerl the head of the
in3~rument and a bridge a3seTr~bly connected to the
~dy, i n which the ~r:in~ are c~uged to vibrate
20 by plucking or picking samaO
In order ~o dexlve an o utput rom such
an electrical }: a~ gui tar or other similar ele ::-
trical mu~ical in~tr~ament, the in~3trument is
converltionaïly provide~ with an elec tromagnetic
25 pick up comprl~iny a number of magnetic element~
~pole plece~3 havi.ng wound thsrearound a conduc:tive
coil. ~ypically, one suc:h ma~etic: element i~
dispo~ed directly benea~h each ~tring oE th~a
ins~rument. The ~tring~ are con~tructed o:~ a
30 m~netizabla ~ub~tance, such as st~el, and~ -ther~-
fore, become par~ o~ tha corlductive p~th :Eox the
m~ etlc lin~ of :Elux o ~he pole piece~.
Pcccrdin~ly, when any of ~he ~rlngs axe cau~d
to vibrat~, thi.~ cau~e3 a d~ sturi:ance in the
35 magnekic ~ield o:E khe as~ciated pole piec0. Thi~
ha~ the e~:Eect of ~eneratin~ a v~l tage ln the
conductive coil t which voltage ~nay be ~uitably
ampliied and tran~mltted ~o a loud3paaker sy~temA
With such an electxoma5~netic pick-up
40 c:on~tru¢tion, ~ xlumber of probl~ms exist
~ ~ ~¢.~ 3
Elec~ric guitars an~ other sim1lax electrical
m~sical instru~ent~ are used ~n areas having
~trong magnetic field~ from lighting ixtures,
motoxs, tran~formers~ and ~he like, and these
magne~ic fields are sensed by the pick-up a~ an
extraneous noi~e ~ouxce. In ~he United States,
such source typically has a frequency of 60 Hz.,
~he u~ual power line frequenc~O These magnetic
~ields induce voltage .in the coil which are also
amplified and ~,ransmit~ed to the loudspeaker s~stem,
manifesting themselves in an objec~ionable hum~
In order ~o overcome this problem, it
i~ known to pxovldç a pick-up for an electr~cal
musical instrument including ~ pair of identical
plck-up as~mblies, each having a plurality o~
magnetic pole pieces and a coil, the pick~up
a~semblies being posi~ionable in parallel, spacedt
clo8ely adjacent relationship~ All of the pole
piece~ of one o~ the pick-up assemblies have their
nor~h poles adjacent to the s~rings and their south
poles xelatively remote ~rom the stxings whereas
all of the pole pieces of the other pick-up assem~ly
having their south poles adjacent to the strings
and their noxth pQl2s relaklvely remote rom the
string~ Th0 coil~ of the two pick-up assemhlies
are wound in oppo~ite dixections and the two coil~
ars connected either in sexies or in paxallel. Be~
cau~e the direo~ion o current flow in each coll
i~ governed by the magnetic polarity, the direction
o current flow in one coil is oppo~ite to that of
the other coil for each ~tring. Elowever, since the
dlrection~ o the windings of khe two coil~ are
oppo~ite, the ~.ignal in~uced in each coil as a
result of 3tring vibxations .i~ additive and the
output signal is the sum of the signals induced
in e~ch coil.
On the other hand, signals picked up by
the coils fxom powex line souxce~ pxoduce cuxrents
in the coil~ whlch are independent of the magnekic
~ D~q~
po:larity and, accordinyly, such power :Linc 90tlrCeS
produce voltages that are :in phase. IIowever, since
the coils are wound in opposite directions, these
in phase siynals cancel and the output signal i5
the dif*erence between the power line signals
induced in each coil. This means that any noise
from power line sources, which is otherwise mani-
fested as an objectionable hum, is effectively
reduced or cancelled. It is for this reason that
such an arrangement is typically characterized as
a humbucking arrangement.
Another industry recognized problem, not
necessarily with a pick~up per se, is the fact tha-t
the human ear is not as sensitive (efficient) to
bass frequencies as it is to midrange and high fre-
quencies. A similar comment may be made with regard
to loudspeakers and other music production systems.
On the other hand, modern music, especially disco
music and rock music ! heavily emphasizes the use of
bass frequencies. Therefore, the music industry has
continuously attempted to boost the bass frequency
output of stringed instruments relati~e to the high
frequency output thereof, especially in the case of
bass guitars. In the past, this has been done by
giving attention to the speakers, baffles, tone
control circuits Eor electro-magnetic pick-ups,
and the like. However, heretofore, none of these
techniques have provided the desired l~vel ~f bass
frequency boost.
BRIEF SUMMARY OF THE INVENTION
According to the present invention~ there
is provided a pick~up for an electrical musical in-
strument of the strinyed type which suhstantially
reduces the high frequency characteristics while
retaining the bass frequency characteristics of the
instrume~t to compensate for the insensitivi-ty of the
human ear of these frequencies. This is achieved by
positioning a pair of pick--up assemblies at opkimal
locations on the body of the instrument and signif-
P~
J~ 3~--4--
icantly decreasing the high frequency output of
that one of the pick-up assemblies which is
positioned relative to the strings so as to be
most sensitive to the bass frequencies~ The
remaining pred.ominantly bass frequency output of
this particular pick-up assembly is added to the
predominantly midrange and high fre~uency output
of the other pick-up assembly to provide the
desired range of frequencies.
Briefly, the present invention relates
to a pick-up for an electrical musical instrument
of the -type including a body, a neck having a head,
a bridye assembly connected to the ~ody, and a
plurality of strings extending between the head
and the bridge assembly and includes: a first pick-
up assembly positioned approximately one-third of
the way between the end of the neck.connected to
the body and the bridge assembly and comprising a
first plurality of pole pieces, at least one for
- each of the strings of the instrument, extending
transversely across all of the strings of the
instrumentj a first coil wound around the first
plurality of pole pieces, the coil extending below
all of the strings of the instrument, and a capacitox
connected across the first coil for providing a shunt
across the ~irst coil for all freguencies other than
useful bass frequencies; and a second pick-up assem-
bly positioned in parallel, spaced relationship to
the first pick-up assembly, approximately halfway
between the firs-t pick-up assembly and the bridge
assembly, and comprising a second plurality of pole
pieces, at least one for each of the strings of
the instrument, extending transversely across all
o~ the strings of the instrument, and a second coil
wound around the second plu~ality of pole pieces, the
coil extending below all of the strings of the instru-
ment, the first and second coils being connected in
series ~etween yround potential and the output of the
.. ~ pick-up.
~" '11
It is thereEore an object of the present
invention to provide a pick-up for an electrical
musical instr~en-t of the stringed type which has a
substantially improved ~requency content. It is
a feature of the presen-t invention to satisfy this
object by providing a pick-up for an electrical
musical instrument having a pair of pick-up assem-
hlies optimally located relative to the head and
bridge of the instrument and means for shunting all
freguencies other than useful bass frequencies from
the pick-up assembly located to have maximum sensi-
tivity to bass frequencies. An advantage to be
derived is that the bass frequency output of such
pick-up is substantially retained while the high fre-
quency output of such pick-up is substantially re-
duced. A further advantage is that the present pick-
up may be used with conventional speakers, baffles,
tone control circuits and the like without the facility
for bass boost. A still further advantage is that
these objectives are achieved in a simple and efficient
manner.
BR:[EF DESCRIPTION OF THE DRAWINGS
.
Still other objects, features, and atten-
dant advantages of the present invention will become
~5 apparent to those skilled in the art from a reading
of the :Eollowing detailed description of the preferred
embodiments constructed in accordance therewith, taken
in con~unction w:ith the accompanying drawings wherein
]ike numerals designate like parts in the several fig-
ures and wherein:
IN THE DRAWINGS
FIGURE 1 is a top plan view o~ an electricalbass guitar incorporating the present invention;
FIGURE 2 is a schematic representation of the
pick-up assemblies of the pick-up of the bass guitar
of FIGURE 1 and showing a first embodiment of the
present invention; and
FIGURE 3 is a view similar to FIGURE 2
showing a second embodiment o~ the present inven~ion.
-5a--
DEA'rA~ D DESCRIPT:[ON O:Li'_'._E -Nvr~ANrrI
Re~erriny now to the d.rawinys and,
more particularly, t.o FI~tJRE 1 thereof, the present
inventi.on is illustrated as being incorporated in
an electrical bass guitar, generally designated 10,
including a body 11, a fretted neck 12, and a head
13 being connected -to one end of neck 12, the other
~ 6 ~
erltl c~:E nec~k :l2 l.~ l.n~J cc)nrlecl:ecl t> body 11. '1'3n-
~.ioned hetween head 13 of bass yultar 10 and a
bridcJe assembly 14 conrlected to body 11 are a
plurali~y of strings 15-18 wh.ich lie in a ~3inyle
plane parallel to the face of body 11.
Strings 15-18 are constructed of a
mas~etizable substance, such as steel, and are
~rae~uated in diameter in a con~7entional manner.
In order to dexive an output from yui~ar 10, it
is provided with arl electromaynetic pic}c-up, yen-
er~lly designated 20, which :Eorms the s~j ec t
matter of the present invenk.ion~ Vibrations of
string~ 15-18, as a result of plucking or picking
the same, produce an electrical signal in pick-up
20, which signal may be suitably amplified and
transmitted to a loudspeaker system~
Pi~k~up 20 has a general configuration
which is known in the prior art. Specifically,
in order to provide humbucking, pick-up 20 include~
at lea~t first and second pick~up assemblies 30
and 40, pick-up a~sembly 30 comprising a plurality
of identical magnetic ~elements (pole pieces) 31-34
which may be magnetized in any one of sev~ral ways
known to tho~e skilled in the art and pick-up
as~embly 40 includes a similar plurality of
iclentical magnetic elements (pole pieces) 41-440
The number of pole pieces 31-34 and the number of
pole pi.eces 41-~4 are preferably identlcal and
preferably the ~ame as the number oE strinys 15-18
In any event, pole pieces 31-34 and 41-44 are
mnunte~ in hody 11 in a conventional manner and
held in po~ition by suitable caps 35 and 45,
re~pectively,
With reference also to FIGU~E 2, it
i8 no~,ed that in this embodiment, all of pole
pi~ces 3:L-34 o~ plck up assembly 30 have their
north poles adjacent to ~trings 15-18 and their
south pole~ relatively remote from string~ 15-18,
whereas all Oæ pole pieces 41-44 o:E pick-up assembly
-7-
~0 have th~ outh pol.e"3 ad ja('ent to ,~tr:Ln~ 15~
and thelr north pol~s .relative1y remote f:rom st.ri.n~s
15~ This arrang~rnent may be ~eversecl.
A coil 36 ~ormed fxom a larg~ numbex
S of turns of fine conductive wire is wound around
pole pieces 3l-34 of pick-up a~sembly 30 whereas a
coil 46 0rm2d from a large number of turns of fine
conductive wire is wound around pole pieces 4l-4~
of pick-up a~sembly 40. The wire in coils 36 and
46 is in3ulated, such as with varnish or lacquer,
and the entire assemkly cornprising the pole pie~
the ~upporting plates, and the coils are preferably
dipped in a suitable varnish or lac~uex/ As is
known in the art~ movement of strings l5~l8 as in
lS the ~trumming or playiny of guitar lO, re~ult~ in
voltages being induced in coil~ 36 and 46, These
voltages are trans~erred to the input circuit o
an amplifier and a loudspeaker system~
In order to provide a humbucking arrange
~0 ment, coils 36 and 46 are wound in opposite direc-
tions. According to the present invention, coils
36 and 46 are connected in series between yround
21 and an output 3.~ad 22. Because ~he direction
of current flow in each coil is governed by the
mag~ekic polarity, the directiQn of current ~low
i~ each coil is opposit~ to that of the other coil
for each string. However, since the dixection of
winding of the two coils is opposite, the voltages
induced in khe coils as a result of strin~ vi-
30 braklans are addi tive and the ~ignal outpu~ onlead 22 .is the ~um o:~ the voltages i.nduced in
e~ch coil ~,
On the other hand~ signals pickad up
by coil~ 36 and ~6 from the power line c~ervice
35 currents in coils 36 and 46 which are indepelldent
of the magnetic polari ty and, accor~lingly, such
extraneous signals produce vol tage~ that are in
phase. However, ~3ince coil~ 36 and 46 are wound
in oppo~ite, directions, t:h~se in phase si.gnal~
cancel ancl f.:he s:igrlal output on l~acJ 2i. is the
di~ference between ~he extrane~ou~ s:ignal voltaye.
induced in each o~ coils 36 and 46O ~h.is meanx
thak any noise from power line sources, t~pically
in the range of 0-150 Hz, which is otherwise
manifested as an objectionable hum, is effectively
reduced or cancelled. It i5 for this reason that
the arrangement may be characteri.zed as a hum
bucking arrang~mentO
Referxing again ko FIGURE 1, it is
immediately recognized -that -the only practical
place to locate pick-up 20 i5 b~tween the end 23
of neck 12 a~d bridge assembly 14. In -theory~ it
is de~irable to place pick-up 20 halfway between
the end points of each string 15-18 since this will
coincide with the point of maximum translation o~'
the string at its fundame~tal frequency of vi
bratio~. As pick-up 20 is moved -from the center
po~ition, it becomes less sensikîve to the funda~
2Q menkal frequencies and more sensitive to khe
harmonic~ The problem results rom the fact that
the locakion of at least one end point keeps
c~anging as the musician moves strings 15-18 inko
contact with the fret board on neck 12. Accordingly,
2$ ~erkain compromises mus~ be macle in choosiny the
loca~ion for pick-up 20.
I:E pick~up 20 is placed close to bridg~
as~emb~y 14, it will always be significantly spaced
*rom the string midpoints and will have little
30 sen~itivi ~y to ~he :Eundamental frequerlcies. On the
other hand, i.:E pi.ck-up 20 is placed very close to
end 23 o~ neck 12 so as to be close to ~he ~tring
midpoint.s wherl the strings are not brou~ht into
::ontact with neck 12 ~ pick-up 20 will have li ttle
.3S sensitivi ty ~o the :Eundamental fre~uenci.es when
the musician engages .strings 15-18 close to end
23 o:~ neck 12. Furthe:rmore, for reasons discu~sed
previously, i t is desired tha~ maxlmum sensi~ivi l;y
exi s t to the fundamenta 1 tones to increase the ba9
~ 9-
sensitivity o:E pick-up 20.
With reEererlce to FIGURES l and 2, the
objects o:E the present invention are achieved by
positioning pick-up assemblies 30 and 40 in parallel
spaced relationship on body ll. As shown in FIGURE
1, pick-up assembly 30 is positioned approximately
one-third of the way between end 23 of neck 12 and
bridge assembly 14. This places pick-up assemb].y
30 a~ a location where it will be close to the mid-
points of strings 15-18 when tne musician is play
ing instrument 101 since statistically, most fretting
is done between the instrument nut 19 and the twelfth
fret. Pick-up assembly 40, on the other hand, is
positioned one-third of the way between bridge assembly
14 and end 23 of neck 12 (half way between bridge
assembly 14 and pick-up assembly 30), where it has
greater sensitivity to the harmonics~ Pick-up
assembly 40 is, therefore, primarily responsible for
reproducing the midrange and high frequencies.
Still urther, and in accordance with the
teachings of the present invention, a capacitor 38
is connected in parallel with coil 36, as shown in
FIGURE 2. Capacitor 38 has a value so that it will
effectively shunt to ground 21 all frequencies other
25 than the useful bass frequencies which it is the de-
sire of the present invention to xetain. In the
case of a bass guitar, where open E has a frequency
of 41.2 Hz, the value of capacitor 38 is selected so
that its effect begins to become significant at approx-
imately lO0 Hz. In other words, one would not want asharp cut-of of frequenc.ies, but would want capacitor
38 to function as an open circuit at frequencies in
the ~0-60 Hz range and to operate as a vir-tual short
circuit at frequencies above 150 Hz. The cro~s-ovPr
35 point would be in the vicin:ity of lO0 Hz. In the case
o a conventional guitar, where open E has a frequency
of 82.41 Hz, the value of capacitor 38 would be sel
ected to have a significant effect at a frequency in
the 150-200 Hz range.
~." ,.,
03l~n~ 3
~ :L C)~-
In other words, it i.5 the teclching o~ the
present invention to locate pick-up assembly 30 at
a location where it will have maximum sensitivity
to the fundamental frequencies of strings 15-18 and
to use a capacitor 38 in parallel with coil 36 to
shunt frequencies other than useful bass frequencies.
Then, the output of pick-up assembly 30 is combined
with the output of pick-up assembly 40, the latter
being sensitive primarily to the midrange and high
10 requencies. The outputs of these two coils are com-
bined by connecting same in series between output
lead 22 and ground 21. When this output is applied
to a conv~ntional amplification and loudspeaker
system, pick-up 20 will provide bass guitar 10 with
15 a substantially reduced high frequency output while
retaining its low frequency output.
According to the en~odiment of the inven~
tion shown in FIGURES 1 and 2, pick-up assembly 30
consists of a single set of pole pieces 31-34 and a
20 single coil 36, as does pick-up assembly 40. However,
other configurations will be evident to those skilled
in the art. For example, and with reference to FIGURE
3, a pick-up 50 for bass guitar 10 may include a pick-
up assembly 60 which is a dual pick-up and a pick-up
25 assembly 80 which is also a dual pick-up. In othex
words, pick-up assembly 60 may include two sets of
pole pieces 61-64 and 65-68, each having its own coil
69 and 70, respectively/ pole pieces 65~68 having an
opposite magnetic orientation from pole pieces 61-64
30 and coils 69 and 70 being wound in opposite directions.
By connectiny coils ~9 and 70 in series or in parallel,
as discussed previously, a humbucking arranyement is
provided. In either event, a capacitor 71 would be
connected in parallel with coils 69 and 70 ~or the
35 reasons described previously with regard to pick-
up 20.
In like manner, pick-up assembly 80 will
include two sets of pole pieces 81-84 and 85-88, each
having its own coil 89 and 90, respectively, pole
.,,~.
.
~ ,,h~D~;~
pieces 81-~4 ar1d pole pi,ece~ 8$-~8 having opposite
magnetic orientations and coils 89 and 90 being
wound in opposite directions. Coils 89 and 90 are
connected in series or in parallel, but the com-
bination is connected in series with coils 69 and70. In the case of pick-up ~0, switch means may
be provided for shorting either coil 69 or coil 70
and switch means may also be provided for simul-
taneously shorting either coil 89 or 90. The
reasons for the desirabil:ity of r~moving one of
the two coils in a dual pick-up assembly from the
- cixcuit are known to those skilled in the art.
Those skilled in the art will also xecognize -that
pick-up 50 is a more ef~ective humbucking arrange-
ment than pick-up 20.
It can therefore be seen that according
to the presen-t invention, there is provided a pick-
up for an electrical musical instrument of the
stringed type which substantially reduces the high
2a ~requency characteristics while retaining the bass
frequency characteristics of the instrument to ,
-compensate for the insensitivity of the human'ear
to these frequencies. This is achieved by posi-
tioning a pair of pick~up assemblies at op-timal
Z5 locati,ons on the body of the instrument and sig-
nificantly decreasing the high frequenc,y output
o~ that one of the pick-up assemblies which is
positioned relative to the strings so as to be most
sensitive -to the bass frequencies. The remaining pre-
dominantly bass frequency output of this particularpick-up assembly is added to the predominantly high
frequency output of the other pick-up assembly to
provide the desired range of frequencies.
While the invention has been described
with respect to the preferred physical emhodiments
constructed in accordance therewith, it will be
apparent to those skilled in the art that various
modifications and improvements may be made without
~ .2~-
d~partirA~ S:rc)m th~ cope an~l sp:Lrlt of the-~ .inve~--
tionO ~ccordincJly, i-t is to be under.stood that
th~ i.nvent.ion i.s not to be limited by the specific
illustx~tive embodiments, but only by the scope
S of the appended claims~
