U.S. patent number 3,674,108 [Application Number 05/085,199] was granted by the patent office on 1972-07-04 for outdoor speaker enclosure.
Invention is credited to David L. Beatty.
United States Patent |
3,674,108 |
Beatty |
July 4, 1972 |
OUTDOOR SPEAKER ENCLOSURE
Abstract
An outdoor speaker enclosure comprising a box enclosing a
loudspeaker, or a plurality thereof, opening outwardly of said box,
and a cover for the speaker opening specially formed to resist the
entry of moisture therethrough but being porous to permit the
unobstructed egress of sound therethrough, said box having
specially formed vents providing both for effective ventilation of
the box interior and also for improving the sound reproduction
quality of the speaker.
Inventors: |
Beatty; David L. (Shawnee
Mission, KS) |
Family
ID: |
22190099 |
Appl.
No.: |
05/085,199 |
Filed: |
October 29, 1970 |
Current U.S.
Class: |
181/149 |
Current CPC
Class: |
H04R
1/2819 (20130101); H04R 1/021 (20130101) |
Current International
Class: |
H04R
1/28 (20060101); H04R 1/02 (20060101); G10k
013/00 (); H04r 001/28 () |
Field of
Search: |
;181/31A,31B,DIG.1
;179/184 |
References Cited
[Referenced By]
U.S. Patent Documents
Primary Examiner: Tomsky; Stephen J.
Claims
What I claim as new and desire to protect by Letters Patent is:
1. An outdoor speaker enclosure comprising:
a. a hollow box-like body member having a speaker opening formed in
a vertically extending wall thereof, said body member being adapted
to have a speaker mounted therein so as to direct sound outwardly
through said speaker opening, and
b. a protective panel secured to the outer surface of the body
member wall in which said speaker opening is formed, and overlying
said opening, said panel including a plurality of sheets of
air-permeable fabric disposed in parallel, spaced-apart relation
with spaces therebetween, said panel having a drain opening formed
therethrough at the bottom of the space between a pair of adjacent
fabric sheets, said drain opening providing for drainage,
exteriorly of said body member, of any moisture collecting between
said adjacent fabric sheets of said protective panel.
2. The structure as recited in claim 1, wherein said body member
has a pair of vent holes formed therein and communicating
respectively with upper and lower portions of the interior
thereof.
3. The structure as recited in claim 2, wherein said vent holes
open downwardly exteriorly of said body member with respect to
adjacent portions of said body member, whereby to inhibit the entry
of moisture into said body member through said holes.
4. The structure as recited in claim 2, with the addition of a pair
of tubes disposed within said body member each with one end higher
than the other, the lower end of each of said tubes communicating
with one of said vent holes, with its upper end opening into the
interior of said body member.
5. The structure as recited in claim 2, wherein said vent holes
open through the vertically extending wall of said body member in
which said speaker opening is formed, said protective panel which
overlies said speaker opening also overlying said vent holes.
6. The structure as recited in claim 1 wherein the outer fabric
sheet of said penal is of relatively tough, coarse fabric through
which water may pass relatively easily, and wherein said panel
includes a plurality of inner sheets of a relatively closely woven
fabric through which water may pass only with relative difficulty,
the drain opening of said panel being disposed between a pair of
said inner sheets.
7. The structure as recited in claim 6 wherein said protective
panel includes two of said relatively closely woven inner fabric
sheets, and wherein said drain opening is disposed between said two
inner sheets.
8. The structure as recited in claim 6 wherein said protective
panel includes an open frame with said fabric sheets overlying the
opening thereof, wherein said drain opening is formed through said
frame intermediate said two inner sheets, and wherein the edge of
said frame defining the bottom of the space between said outer
fabric sheet and the adjacent inner sheet is inclined downwardly
toward said outer sheet.
Description
This invention relates to new and useful improvements in speaker
enclosures for radio, high-fidelity, and stereophonic sound
reproduction systems, and has particular reference to speaker
enclosures intended for usage outdoors, as on patios, porches, and
the like, where they are necessarily exposed to the weather at
least to some degree.
Exposure to the weather, particularly to rain, snow, dew,
condensation, and other moisture, creates certain problems in
connection with speaker enclosures. The enclosure must of course be
supported by some means providing that the enclosure itself cannot
directly engage any supporting surface on which moisture can
collect, and from which it could seep into the enclosure. The
speaker itself must be protected against rain or other moisture,
even when said rain may be driven by a high wind. At the same time,
the speaker opening of the enclosure should not be covered by any
completely non-porous, waterproof layers, as these would muffle and
otherwise reduce the quality of the sound reproduced by the
speaker. Also, the enclosure itself should be well ventilated to
provide for the disposition of any moisture which may find its way
therein, or which may form therein by condensation due to
substantial temperature changes in the surrounding air.
Accordingly, the object of the present invention is the provision
of an outdoor speaker enclosure which fulfills all of the above
enumerated requirements, in a novel, efficient manner. The present
invention, to this end, involves two principal innovations. First,
the speaker opening of the enclosure is provided with a special
covering formed in a novel manner to resist the passage of rain or
other moisture therethrough, while at the same time permitting
passage of air therethrough with sufficient freedom not to muffle
or otherwise detract from the quality of the sound reproduced by
the speaker. Generally, this is accomplished by a cover including a
plurality of spaced apart layers of cloth of successively greater
resistance to the passage of water therethrough, and the provision
of means for draining away any moisture from the spaces between
said layers.
Second, there are provided special vents or openings for
ventilating the enclosure. Speaker enclosures are already often
provided with vents for the purpose of allowing the escape of sound
generated in the enclosure from the inside of the speaker cone.
Such vents thus cause the enclosure to act as a "sounding box" for
the speaker, and have been found quite effective in strengthening
and reinforcing the bass notes or other low-frequency sounds
reproduced by the speaker. However, such vents have heretofore not
been so arranged or disposed either to inhibit the entry of
moisture into the enclosure, or to provide for circulatory
ventilation of the interior thereof. The present invention provides
for the formation and disposition of the vents whereby to perform
these additional functions.
Other objects are simplicity and economy of construction, and
efficiency and dependability of operation.
With these objects in view, as well as other objects which will
appear in the course of the specification, reference will be had to
the accompanying drawing, wherein:
FIG. 1 is a front elevational view of an outdoor speaker enclosure
embodying the present invention,
FIG. 2 is a sectional view taken on line II--II of FIG. 1, with
parts left in elevation,
FIG. 3 is a sectional view taken on line III--III of FIG. 2,
FIG. 4 is a sectional view taken on line IV--IV of FIG. 2, with
parts left in elevation, and showing a slight modification of
structure, and
FIG. 5 is an enlarged, fragmentary sectional view taken on line
V--V of FIG. 1.
Like reference numerals apply to similar parts throughout the
several views. The speaker enclosure forming the subject matter of
the present invention includes a body member which may be formed of
wood or any other suitable material, and may have the form of a
generally rectilinear box, having a floor 2, left and right side
walls 4 and 6, rear wall 8, front wall 10, and a top wall
consisting of two inclined panels 12 and 14 whereby to form a
peaked roof to better shed rain and the like, all of said members
being rigidly connected together by any suitable means, not shown,
whereby to form a unitary structure. The enclosure is supported
above any supporting surface 16 by short legs 18 affixed thereto at
each of its four corners. Roof panels 12 and 14 are extended
outwardly to form eaves overhanging all of the front, rear, and
side walls of the enclosure, and front wall 10 is recessed inwardly
from the forward edges of side walls 4 and 6. A circular speaker
opening 20 is formed in front wall 10, and a speaker 22 is affixed
in said opening as by bolts 24, whereby to direct sound reproduced
thereby forwardly from the enclosure. The speaker includes a
speaker cone (not shown) coaxial therewith, which generally seals
opening 20 of front wall 10, and which is vibrated by speaker coil
26 to generate sound. The rearward face of said cone is exposed to
the interior of the enclosure through openings 28 formed in the
speaker frame, so that vibration of the cone also vibrates the air
within the enclosure. The necessary electrical connections to the
speaker may be made by any suitable means, not shown.
The forward surface of front wall 10, of course including speaker
opening 20 and the speaker 22 mounted therein, is covered by a
protective panel indicated generally by the numeral 30. As best
shown in FIGS. 1, 2, 4, and 5, said panel includes three planar,
open frames 32, 34 and 36, formed of wood or other suitable
material, assembled in overlying, coextensive relation to form a
single composite frame. Overlying the outer or forward face of
forwardmost frame 32 is a sheet 38 of stout, relatively coarse
textile fabric. The material of sheet 38 should be of material
sufficiently strong to resist damage by the physical scratching,
gouging, and the like to which it may be subjected in outdoor
usage, and is preferably formed of a synthetic material to resist
damage by mildew and the like. Synthetics of the type and weight
commonly used for outdoor carpeting has been found satisfactory.
Water may pass through material of this sort with relative ease,
and sheet 38 would hence not, of itself alone, adequately protect
speaker 22 against moisture.
Panel 30 also includes two sheets 40 and 42 of a very closely woven
moisture-repellent textile fabric overlying the entire area of the
panel, the edges of sheets 40 and 42 being clamped respectively
between frames 32 and 34, and between frames 34 and 36, whereby
textile sheets 38, 40, and 42 are supported in closely spaced
apart, parallel relation. A closely woven nylon fabric, such as is
commonly used as a tenting material, has been found satisfactory
for use in sheets 40 and 42. Coarse front sheet 38 is folded
rearwardly around the edges of panel 30 and secured to the rearward
surface thereof as by tacks 44 (see FIG. 5). Panel 30 is secured
bodily against the forward surface of front enclosure wall 10 by
screws 46. Referring to FIG. 5, it will be seen that the upper edge
of the lower horizontal leg 32A of frame 32 is inclined forwardly
and downwardly as indicated at 48, and that central frame member 34
has no horizontal lower leg at all, thereby providing an opening 50
between textile sheets 40 and 42 extending all the way to the
extreme lower edge of panel 30. These latter provisions are for the
purposes of drainage, as will appear. The upper edge of panel 30 is
protected by the eaves formed by roof panels 12 and 14, and the
vertical side edges of said panel are protected by their inclusion
between the portions of side walls 4 and 6 projecting forwardly of
front wall 10 (best shown in FIG. 2), so that water cannot work
around the edges of the panel.
Also provided are a pair of vent tubes 52 and 54. As shown, said
tubes are elongated and of rectangular cross-sectional contour,
tube 52 being affixed vertically to the inner surface of side wall
4, opening at its upper end into the enclosure and having its lower
end disposed in registry with a hole 56 formed in floor 2 with a
screen 58 interposed therebetween to prevent the entry of insects
into the enclosure. Tube 54 is affixed to the inner surface of roof
panel 14, with its upper end opening into the enclosure and its
lower end registered with a hole 60 formed in side wall 6 beneath
the eave formed by said roof panel, with a screen 62 interposed
therebetween.
In operation, it will be seen that rain or the like can pass with
relative ease through the coarse textile sheet 38 forming the outer
layer of protective panel 30 covering the speaker. However, sheet
38 does prevent the passage of much of the moisture, and
furthermore absorbs much of the force of any wind which may be
driving the rain, damping and reducing the air flow to the extent
that any moisture entering between sheets 38 and 40 impinges
against sheet 40 with much less force, and in much smaller
quantities, than it originally engaged sheet 38. This together with
the additional fact that sheet 40 (and 42) is formed of a very
closely woven, moisture-shedding cloth such as nylon tenting
material, results in fact that very little water ever passes
through sheet 40, and virtually none through sheet 42. Any water
collecting between sheets 38 and 40 drains outwardly through sheet
38 by reason of the bevel 48 of frame 32 at the lower edge of the
space between these sheets, and any water collecting between sheets
40 and 42 drains downwardly through opening 50 formed by the
elimination of the bottom leg of frame 34. The lower end of opening
50 is covered by sheet 38, but water can pass therethrough easily,
thus the speaker is protected from rain or other moisture, while
there are still air passages through the panel as are necessary for
the efficient undistorted transmission of sound therethrough. Panel
30 is sufficiently effective that even when a stream from a garden
hose is directed thereagainst with full force, substantially no
water passes through inner sheet 42 thereof. This is a far more
rigorous test than the panel would be required to withstand in any
normal usage.
At the same time, the enclosure is continuously ventilated, to
evaporate and carry away any moisture which may for example form
therein by condensation, by air entering therein through tube 52,
circulating through the interior thereof, and leaving through tube
54. As previously discussed, the venting of speaker enclosures for
the acoustical purpose of strengthening and reinforcing
low-frequency sounds is not new. Vent tubes 52 and 54 also perform
this function. However, such prior acoustical venting has
ordinarily been performed by a single vent not adapted to perform
the circulatory ventilation required in an outdoor enclosure. The
present structure supplies this lack of prior structures by
dividing the vent into two sections disposed respectively adjacent
the bottom and top of the enclosure, whereby to promote air
circulation, by disposing the atmospheric ends of the openings in
protected zones to at least inhibit the entry of wind-driven rain
therein, and by the provision of tubes 54 extending upwardly inside
of the enclosure from the atmospheric openings. These tubes
virtually preclude the entry of any water into the enclosure
through the vents, in any normal usage. The quality of the sound
emanating from the vents is improved further by the provision of
means preventing reflection, or reverberation, of sound between
opposite interior walls of the housing. For this reason, floor 2,
left side wall 6 and back wall 8 of the enclosure are provided with
linings 64 consisting of slabs of sound-absorbing acoustical
material.
FIG. 4 shows a structural modification supplying an alternative, or
additional, means of venting the enclosure, consisting of short
tubes 66 and 68 affixed in openings provided therefor in front wall
10 of the enclosure, respectively above and below speaker 22, but
both behind protective panel 30 covering the front of the
enclosure. These tubes provide for circulation of air through the
enclosure, as do tubes 52 and 54, and are protected against the
ingress of moisture therethrough by panel 30, in the same manner
that said panel protects speaker 22. The use of tubes 66 and 68,
rather than simply holes formed in front wall 10, is dictated by
acoustical considerations with which this invention is not directly
concerned, it having been found that tubular vents having certain
proportions of length and cross-sectional contours produce better
sound effects than others. These considerations apply also to the
design of tubes 52 and 54. While tubes 66 and 68 have the advantage
of being simpler and cheaper to install than tubes 52 and 54, they
are less efficient for the purposes intended than tubes 52 and 54.
Hence, while the two sets of tubes may be used either alternatively
or concurrently, the use of tubes 52 and 54 is preferable if only
one set is used. The lack of efficiency of tubes 66 and 68 arises
from the fact that protective panel 30, while necessarily permeable
to some degree to the flow of air therethrough, nevertheless still
imposes considerable restriction to air flow therethrough. This
restriction has little effect on high-frequency sounds, since the
physical volume of air displaced by the speaker in high-frequency
sound is very small, and very little air must be forced through the
panel. However, with sounds of very low frequency, which emanate
principally from the vents, large quantities of air are moved,
resulting in quite noticeable inward and outward "puffing" of air
through the vents. Hence, any substantial restriction of the flow
of air through the vents results in muffling of the sound, so that
the substantially unrestricted vents 52 and 54 are preferable. The
flow restriction provided by panel 30 also inhibits the free
circulatory ventilation of air desired in the present case for
drying purposes. While the use of tubes 52 and 54, opening through
the bottom and side of the enclosure, causes the low-frequency
sounds to be initially directed in directions different from the
axis of speaker 22, this is not disadvantageous. While high
frequency sounds are directional in character, making it desirable
to aim the speaker toward a desired listening area, low frequency
sounds are more pervasive and non-directional in character, so that
it makes little difference if the vents open downwardly, laterally,
or even rearwardly of the speaker.
While I have shown and described certain specific embodiments of my
invention, it will be readily apparent that many minor changes of
structure and operation could be made without departing from the
spirit of the invention.
* * * * *