close

Вход

Забыли?

вход по аккаунту

?

JPH11234783

код для вставкиСкачать
Patent Translate
Powered by EPO and Google
Notice
This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate,
complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or
financial decisions, should not be based on machine-translation output.
DESCRIPTION JPH11234783
[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a
front loaded horn loudspeaker system with a screw horn.
[0002]
2. Description of the Related Art A front loaded horn system (hereinafter referred to as FLH) is
known as one of the prior art for expanding the low frequency range of a speaker system. FLH is
a speaker system of the type in which the horn is attached in front of the diaphragm of the
speaker unit, and since sufficient load can be applied to the bass, the sound pressure can be
increased in the bass range, and transient characteristics Has a feature that it can reproduce lowpitched bass.
[0003]
On the other hand, as a drawback of FLH, 1) If it is attempted to select a low cut-off frequency
which indicates the bass limit in order to widen the reproduction band, it becomes very large and
the practicability for home use is lost. 2) In order to miniaturize the system, a system equipped
with a short horn aiming for a baffle plate effect rather than the horn effect has been put to
practical use, but this is only for medium sound. 3) In order to make the horn as small as
possible, a bending horn in which the middle of the horn is folded is put to practical use.
03-05-2019
1
However, since the structure is complicated, mass production is difficult and it must be
expensive. 4) Since the bending horn is formed by connecting straight sound paths, it is not
possible to avoid sound quality deterioration due to resonance at the straight portion and air flow
disturbance at the bending portion.
[0004]
Thus, although FLH according to the prior art has excellent features, it has not been widely
spread due to many drawbacks.
[0005]
SUMMARY OF THE INVENTION The present invention has been made in view of the abovedescribed circumstances, and has a speaker system which has a good transient characteristic, a
small size, a structure which is easy to mass-produce, and little sound quality deterioration It is
intended to be provided.
[0006]
The speaker system of the present invention is constituted by the following items.
[0007]
(1) It has a cabinet which consists of a screw horn provided in the front of a speaker unit, and an
empty room provided in the back of the speaker unit, and the screw horn has a spiral shape
provided in a coaxial double pipe and its gap A speaker system characterized in that it is an
acoustic pipe formed by a partition plate.
[0008]
(2) The speaker system according to (1), wherein a small air chamber is provided close to the
front of the speaker unit, and the small air chamber is connected to the throat of the screw horn.
[0009]
(3) The speaker system according to (1), wherein the second speaker unit is attached to the baffle
plate of the empty space.
[0010]
(4) The speaker system according to any one of (1) to (3), wherein a sound absorbing material
03-05-2019
2
consisting of an accumulation of air columns having a length distribution is installed in a vacant
space and a small air chamber.
[0011]
The three-dimensional spiral horn (hereinafter referred to as a screw horn), which is an acoustic
pipe formed by the coaxial double pipe and the spiral partition plate provided in the gap, used in
the present invention is a front loaded horn type system It can be applied to (FLH).
[0012]
The present invention provides an FLH in which the screw horn is provided on the front surface
of the speaker unit and an empty space is provided on the rear surface.
The cavity may be sealed or may have ports that allow the construction of a phase reversal
system.
[0013]
The screw horn is a three-dimensional spiral horn formed by providing a spiral partition in the
gap between coaxial double pipes consisting of an inner pipe and an outer pipe, and the crosssectional area of the sound path is usually the horn opening. It will be gradually expanded
toward the department.
With the screw horn having a three-dimensional structure, space is effectively used and the FLH
can be miniaturized.
[0014]
Although FLH generally lowers the sound pressure level in the high region significantly, the
above-mentioned configuration FLH of the present invention is similar, and therefore can be used
as a bass system.
03-05-2019
3
In order to provide an independent speaker system, a second speaker unit may be attached to the
baffle plate of the empty space.
[0015]
In general, the sound radiated to the outside from the opening through the horn has a phase
delay proportional to the distance of the sound path formed in the horn, and the sound pressure
of the middle to high sound component is attenuated.
The sound path length of the screw horn of the present invention has a large difference between
the shortest distance along the inner circumference of the sound path and the longest distance
along the outer circumference, so the sound emitted from the front of the diaphragm of the
above speaker unit for horn There is a distribution of phase delays before the radiation is emitted
from the horn opening.
[0016]
In the case of a normal horn system, it should be observed that the sound emitted from the horn
opening and the sound on the front of the second speaker unit interfere in phase at a specific
frequency to produce a sharp valley. However, in the present invention, the sound pressure
frequency characteristics with few valleys are obtained by the above-mentioned effects of the
phase delay distribution and the attenuation of middle high and low tone components.
[0017]
In order to further ensure the prevention of the generation of valleys in the sound pressure
frequency characteristics, a small air chamber is provided on the front of the speaker unit for the
horn, and a method of absorbing middle to high range by its acoustic capacitance; By installing a
sound absorbing material inside the air chamber, it is possible to use a method of absorbing
middle to high pitch and the like.
[0018]
As the above-mentioned sound absorbing material, an aggregate of air columns having a length
distribution, which is produced by obliquely cutting a laminate of cardboard or the like, is
03-05-2019
4
particularly preferable.
A sound absorbing material consisting of an accumulation of air columns absorbs sound by
converting sound energy into heat energy by the resonance of multiple air columns having
different lengths, and is effective in a wide frequency band.
[0019]
Since the screw horn used in the present invention is formed by a smooth curved surface,
substantially no straight sound path or sharp bending portion exists, thus reducing the sound
quality deterioration due to unnecessary resonance or air flow disturbance. be able to.
Furthermore, the goodness of transient characteristics in the low range, which is an advantage of
FLH, is inherited, and good sound quality is realized in combination with the advantages of the
speaker system of the present invention.
[0020]
Further, according to the manufacturing method described later, the screw horn has a structure
that is easy for industrial mass production, and a relatively inexpensive speaker system can be
provided.
[0021]
Embodiments of the present invention will be described below with reference to the drawings.
[0022]
EXAMPLE 1 FIG. 4 shows an example of the basic configuration of the present invention, which
is useful as a bass system.
In FIG. 4, the cabinet has a screw horn provided on the front surface of the speaker unit 1 for
horns and a cabinet 7 formed on the back surface of the speaker unit 1 with a vacant space 7.
03-05-2019
5
The screw horn is formed by inserting the spiral shown in FIG. 2 into the outer tube 4 having a
circular internal cross-sectional shape.
[0023]
The spiral in FIG. 2 is formed by arranging a spiral partition plate 3 around the inner pipe 2 to
form a spiral valley 5.
When the spiral is inserted into the outer pipe 4, the outer pipe 4 and the inner pipe 2 constitute
a coaxial double pipe, the partition plate 3 is provided in the gap, and the valley 5 has a threedimensional spiral sound path shown in FIG. It will be 5.
[0024]
If necessary, a small air chamber 8 can be provided on the front of the horn speaker unit 1, and
the sound on the front of the speaker unit 1 passes through the small air chamber 8 and passes
through the entrance of the helical sound path 5, ie, the throat 16. After the helical sound path 5,
the high and high tone components are attenuated to some extent, and the low tone component
and the remaining middle and high tone components are emitted from the opening 11 to the
outside.
The sound propagation direction is indicated by the arrows in FIG.
The shape in the vicinity of the throat 16 is shown in FIG.
The direction of rotation of the spiral may be either left or right.
[0025]
The length of the helical sound path 5 is defined as the length measured along the center of the
03-05-2019
6
sound path, that is, the middle point in the sound channel vertical direction by the arithmetic
mean diameter of the inner diameter and the outer diameter, 0.3 m or more and 4 m or less Is
preferred. When the length is less than 0.3 m, the attenuation of the middle to high tone
component is insufficient. When the length exceeds 4 m, the sound quality is deteriorated
because the time delay until the sound radiated to the outside through the opening 11 reaches
the listening position can not be neglected, and the air flow resistance in the sound path is
further increased. Causes problems such as a decrease in sound output. There is no particular
limitation on the number of rotations of the spiral, but one or more times is desirable to
sufficiently attenuate middle-high tone components.
[0026]
The cross-sectional area of the helical sound path is defined as the cross-sectional area of the
sound path cut by a plane passing through the central axis of the coaxial double tube. The
sectional area of the throat 16 is preferably in the range of 0.1 to 15, assuming that the effective
vibration area of the speaker unit is 1. The cross-sectional area of the helical sound path may be
constant in the direction of sound travel, but it is usually preferable to be gradually enlarged.
[0027]
In the case of expanding the cross-sectional area of the helical sound path, the expansion may be
continuous and smooth, and is not necessarily exponential. As a method of expanding the crosssectional area, there are a method of expanding the height of the sound path, a method of
expanding the width, and a method of expanding both simultaneously. 4 and 2 show the case
where only the height is enlarged and the width is fixed. Apart from FIGS. 4 and 2, the width of
the sound path can also be expanded by increasing the diameter of the outer pipe toward the
bottom or reducing the diameter of the inner pipe.
[0028]
It is desirable that the cross sectional shapes of the outside of the inner pipe 2 and the inside of
the outer pipe 4 used in the present invention are both circular. A circular cross-sectional shape
is easier to manufacture and can form a sound path substantially free of linear portions in the
sound traveling direction, so that resonance is less likely to occur and there is less turbulence in
the air flow. The outer cross-sectional shape of the outer tube 4 is not necessarily circular, and
03-05-2019
7
may be square or the like. The inner pipe 2 and the outer pipe 4 are coaxially arranged to form a
coaxial double pipe.
[0029]
The inner pipe 2 is not necessarily required to be a pipe, and may be a rod-like body having no
internal space. When the inner pipe 2 is a pipe, a filler such as sand or lead particles can be put
in the pipe to reduce the adverse effect on the sound quality due to the vibration of the inner
pipe. The diameters of the outer pipe and the inner pipe do not have to be constant, and as
described above, they may be changed for the purpose of expanding the sound path crosssectional area.
[0030]
The spiral partition 3 can be formed in various ways. For example, there is a method of winding a
band-shaped rubber plate, a cabtire cable, etc. around the inner pipe 2 in multiple layers and
fixing them with an adhesive. When the spiral partition 3 is formed of a flexible material such as
a cabtire cable, it is desirable to increase the rigidity of the spiral partition 3 by applying an
epoxy resin or the like in order to prevent vibration. The resulting helical body is inserted into
the outer tube 4 and the outer surface of the helical partition 3 and the inner surface of the outer
tube 4 are joined with an adhesive to form the helical sound path 5.
[0031]
In order to industrially mass-produce the helical sound path, various methods can be adopted
other than the above-described methods, but plastic injection molding is particularly preferable.
That is, only the portion where the outer pipe 4 and the spiral are integrated or only the spiral is
divided into blocks per rotation of the spiral partition 3 or each rotation less than 1 if necessary,
and each block is respectively formed by injection molding It is a method of forming and joining
a plurality of obtained blocks to form a helical sound path or a helical body. The above
manufacturing method and the like which do not require a high level of skilled artisans can be
adopted because the structure of the speaker system of the present invention is excellent in mass
productivity.
03-05-2019
8
[0032]
In order to attach the speaker unit 1 and the cavity 7 to the above-mentioned coaxial double
pipe, a tube having a T-shaped or L-shaped joint or the like can be used. A sound absorbing
material is installed inside the vacant space 7 and the small air chamber 8 (not shown).
[0033]
FIG. 5 shows the sound pressure frequency characteristics of the above embodiment, in which a
wide bass range and attenuation of middle and high range are observed.
[0034]
Second Embodiment FIG. 1 shows a system in which a second speaker unit 6 mainly sharing the
middle to high frequency range is attached to a baffle plate 10 of a vacant room in the system of
the first embodiment to provide a complete speaker system.
The number of the speaker units 6 may be one as shown in the drawing, or a plurality of the
speaker units 6 may be used for the middle range and the high range.
[0035]
As shown in the drawing, the inside of the vacant room 7 may be divided between the two
speaker units by the partition plate 17 or may be without the partition plate.
[0036]
The orientations of the speaker unit 6 and the horn opening 11 are arbitrary and may be the
same, and may be reversed or rotatable.
[0037]
FIG. 6 shows sound pressure frequency characteristics of the above embodiment, in which the
sound of the front surface of the speaker unit 6 is added to the bass radiated from the horn
opening 11, and a wide reproduction band is realized.
03-05-2019
9
From the effects of the phase delay distribution, the small air chamber, the sound absorbing
material, etc., it can be seen that valleys due to interference are not generated.
[0038]
As described above, the present invention is an FLH provided with a screw horn, which realizes a
speaker system having a good transient characteristic, a small size, a structure easy to massproduce, and little deterioration in sound quality. Can.
03-05-2019
10
Документ
Категория
Без категории
Просмотров
0
Размер файла
19 Кб
Теги
jph11234783
1/--страниц
Пожаловаться на содержимое документа