Note : Les descriptions sont présentées dans la langue officielle dans laquelle elles ont été soumises.
21911~7
This invention relates to a speaker assembly, and
specifically to a speaker assembly for reproducing sound,
particularly in the lower acoustic frequencies.
Over the years, a great deal of effort has been
expended in the design and production of speaker apparatuses.
Examples of such apparatuses are described in United States
Patents Nos. 2,097,289, which issued to H.F. Olson on October
26, 1937; 2,167,625, which issued to E.P. Albano on August 1,
1939; 2,475,782, which issued to G.M. Giannini on July 12,
1949; 2,689,016, which issued to H.C. Lang on September 14,
1954; 2,878,887, which issued to Van R. Potter on March 24,
1959; 3,072,212, which issued to R.Y. Chapman on January 8,
1963; 3,393,766, which issued to L.H. Mitchell on July 23,
1968; 4,301,889, which issued to David V. Tralonga on November
24, 1981; 5,092,424, which issued to W.P. Schreiber et al on
March 3, 1992; 5,111,509, which issued to Akihiko Takeuchi et
al on May 5, 1992; 5,189,706, which issued to Tatsuo Saeki on
February 23, 1993 and 5,479,520, which issued to Joris A.M.
Nieuwendijk et al on December 26, 1995.
Partly as a result of the above described
inventions, and to meet the demands of consumers, there is
large number of speaker assemblies available in the
marketplace. Such assemblies include one or more speakers
mounting in a single or a plurality of cabinets or housings.
In general, a sound system includes two speaker assemblies for
achieving stereophonic sound or simply "stereo". For the true
aficionado, two speaker assemblies are not enough. In order
to achieve good stereophonic sound, three and often more
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speakers are employed. In fact, it is not uncommon to use a
plurality of speaker apparatuses which occupy a large portion
of a sound or music room.
The biggest problem facing the manufacturers of such
apparatuses is to provide a product which faithfully
reproduces sound in the lower acoustic frequencies, i.e. so-
called woofers. The problem lies not in the speaker itself,
but in the cabinet or housing carrying the speaker. For a
variety of reasons, including vibration and echo, faithful
sound reproduction or fidelity is difficult to achieve. In
spite of considerable effort and expense, there still exists a
need for a speaker assembly, which accurately reproduces sound
in the lower acoustic frequencies.
The object of the present invention is to meet the
above defined need by providing a relatively simple speaker
assembly, which is easy to build, and which is capable of
faithfully reproducing sound in the lower acoustic
frequencies.
Accordingly, the present invention relates to a
speaker assembly comprising housing means; first partition
means dividing the interior of said housing means into a
speaker chamber for receiving a speaker, and a sound outlet
chamber; sound outlet box means in said outlet chamber; sound
outlet tube means in said outlet chamber; and solid material
in said outlet box means surrounding said outlet tube means
for preventing vibration of said tube means during the passage
of sound therethrough.
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The invention is described hereinafter in greater
detail with reference to the accompanying drawings, which
illustrate a preferred embodiment of the invention, and
wherein:
Figure 1 is a perspective view of a speaker assembly
in accordance with the present invention;
Figure 2 is a partly sectioned, top view of the
speaker assembly of Fig. 1 with the covers removed;
Figure 3 is a partly sectioned, exploded,
perspective view of the speaker assembly of Figs. 1 and 2 as
seen from above and one side;
Figure 4 is a cross-sectional view of an outlet box
used in the speaker assembly of Figs. 1 to 3;
Figure 5 is a partly sectioned, perspective view of
one end of the housing of the speaker assembly of Figs. 1 to
3;
Figure 6 is a partly sectioned, perspective view of
the other end of the housing of Fig. 5, and
Figures 7 and 8 are longitudinal sectional views of
a second embodiment of the speaker assembly, the two view
being perpendicular to each other.
Referring to Figs. 1 to 3, a speaker assembly in
accordance with the invention includes a housing generally
indicated at 1. The housing is defined by a bottom wall 2,
side walls 3, end walls 4 and 5, and a frusto-pyramidal cover
6. The cover 6 includes inclined side and end walls 8 and 9,
respectively, and a rectangular top wall 10.
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A vertical partition 11 extends across the housing 1
between the side walls 3. A second, horizontal partition 12
extends between the side walls 3 and between the vertical
partition 11 and one end wall 4. The partitions 11 and 12
divide one end of the housing 1 into an upper, speaker chamber
13 and a lower, intermediate chamber 14. A speaker 16 is
mounted on the partition 12 over a circular opening 17 in the
partition 12 for admitting sound into the intermediate chamber
14. Power is fed to the speaker 16 via jacks 18 mounted in
the end wall 4. A polyester fiber batt 20 (Fig. 2) covers
the input or top end of the speaker 16 to prevent or at least
to reduce echo.
Sound from the speaker 16 travels through a gap in
the form of an arch-shaped opening 21 in the bottom of the
partition 11 into a sound outlet chamber 22. The outlet
chamber 22 is defined by the partition 11, the side walls 3,
the end wall 5 and a top plate or cover 25. As best shown in
Figs. 3 and 6, the top 25 extends between the side walls 3,
and between the vertical partition 11 and the end wall 5.
An outlet box 27 is mounted in the center of one end
of the outlet chamber 22 abutting the end wall 5. Spacers or
vertical partitions 28 extend between the inner end 29 (Fig.
2) of the outlet box 27 and the side walls 3, and from the
bottom wall 2 of the housing 1 to the top plate 25. The areas
on each side of the outlet box 27 are filled with sand 30 or
another solid material, which, along with the partitions 28,
firmly locates the outlet box 27 in the outlet chamber 22 and
prevents any vibration of the box.
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With reference to Figs. 4 to 6, the rectangular
outlet box 27 is defined by a bottom wall 31, a top wall 32,
side walls 33, and end walls 34 and 35. A sound outlet tube
36 extends through the end wall 34, the center of the box 27,
the end wall 35 and the end wall 5 of the housing 1. The
outlet tube 36 is formed of a hard plastic - in this case ABS
plastic. The entire interior of the box 27 surrounding the
tube 36 is filled with sand 38 (Fig. 4) andtor epoxy resin to
prevent vibration of the tube 36. A suitable epoxy resin is
sold by Sika Canada Ltd, Pointe Claire, Quebec under the trade
mark Sikadur 32 Hi-Mod.
During production of the speaker assembly, the
bottom of outlet box 27, and the outlet tube 36 are assembled.
The bottom of the housing 1 and the cover 6 are assembled
separately, and the speaker 16, the jacks 18 and the batt 20
are placed in the chamber 13. Before attaching the top wall
32 to the remainder of the outlet box 27, the box is filled
with sand and/or epoxy resin, or another solid material. The
box 27 is then sealed and mounted in the bottom of the housing
1 with the outlet end of the tube 36 extending through an
opening 39 ~Figs. 1 and 3) in the end wall 5 of the housing 1.
The spacers 28 are mounted in the housing 1 on each side of
the inner end of the box 27, the area on each side of the box
27 is filled with sand, and the cover 25 is mounted on the
partition 11, the box 27 and the spacers 28. Finally, the
preassembled cover 6 is mounted on the bottom of the housing 1
to complete the speaker assembly.
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The preferred material used in the construction of
the housing 1 (including the cover 6) is a medium to high '
density particle board of the type composed of compressed
sawdust and resin. While particle board is heavy, the
material is inexpensive and relatively easy to assemble.
While sand is the preferred filler for the outlet box 27 and
- the area on each side thereof, any other easily compacted
dense, preferably granular material can be used. Upon
completion of the assembly, the exterior of the housing 1 is
spray painted or otherwise sealed to resemble wood or to
achieve other effects. The coating of the exterior of the
housing further prevents the escape of sound from the housing
except via the outlet tube.
In operation, sound emanating from the speaker 16
passes through the opening 17 in the partitio~ 12 into the
intermediate chamber 14, and thence through the opening 21 in
the partition 11 into the outlet chamber 22. The sound then
travels through the outlet tube 36, exiting the speaker
assembly at the end wall 5. The sand and/or epoxy resin in
the areas on each side of the outlet box 27 prevent vibration
of the box; and the sand in the box 27 prevents vibration of
the tube 36. The result is extremely clear sound
reproduction.
Referring to Figs. 7 and 8, a second embodiment of
the invention includes a housing generally indicated at 40
defined by a bottom wall 41, side walls 42, front and rear end
walls 43 and 44, and a top wall or cover 45.
2l9ll~7
A horizontal partition 47 extends across the housing
40 between the side walls 42 and between the end walls 43 and
44, dividing the interior of the casing into an upper speaker
chamber 48 and a lower sound outlet chamber 49. A speaker 50
is mounted on the partition 47 over a circular opening 52 in
the partition for admitting sound into the outlet chamber 49.
Power is fed to the speaker 50 via jacks 53 (one shown)
mounted in the rear wall 44 of the housing 40. A polyester
batt 54 covers the top end of the speaker 50 to prevent echo.
A second partition 56, which is spaced apart from
the partition 47, extends between the side walls 42 and from
the front wall 43 towards the rear wall 44. The partition 56
stops short of the rear wall 44, leaving a gap 57 through
which sound can travel to'a sound outlet box 58. The box 58,
which is similar to the box 27, is mounted in the bottom
center of the housing 40 abutting the front wall 43. The box
58 contains a sound outlet tube 60, which extends through the
box and through the front wall 43 of the housing 40. Sand
and/or epoxy (not shown) fills the remainder of the interior
of the box 58. Vertical partitions or spacers 61 (Fig. 8) are
provided on each side of the inner end of the box 58, and the
area between the sides of the box 58 and the side walls 42 are
filled with sand 63 or another solid material.
The spacers 61 can be mounted either at the inner
end of the box 58 remote from the front wall 43 of the housing
40 or located between the ends of the box 58, i.e. closer to
the front wall 43. In other words, it is not essential that
the sand or other solid material fill the entire area on each
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side of the box 58. However, it is preferable that the sand
borders most or all of the area beside each side of the box
58.
It will be appreciated that in its simplest form the
speaker assembly includes a housing containing a partition
dividing the interior thereof into a speaker chamber for
receiving a speaker, and a sound outlet chamber containing an
outlet box of the type described hereinbefore, the box being
firmly anchored in the outlet chamber.
Thus, there has been described a structurally
simple, high fidelity speaker assembly, which is relatively
easy to assemble and inexpensive to produce, and which
reproduces undistorted sound, particularly in the lower
acoustic frequencies.
