close

Вход

Забыли?

вход по аккаунту

?

DESCRIPTION JPH04309098

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 JPH04309098
[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a
loudspeaker system of a bass reflex cabinet which enhances the bass output of the loudspeaker.
[0002]
2. Description of the Related Art In order to enhance the bass output of a speaker, it is generally
practiced to invert the sound output emitted from the back of the speaker and to guide it to the
front side. FIG. 3 shows a conventional speaker system in which a speaker 20 for sound emission
is disposed on the front side of a housing 10, and a phase inversion baffle is configured by an
acoustic duct 30. As shown in FIG. This phase-reversal baffle system is known to further enhance
the output of the bass by increasing the length of the acoustic duct 30, but the length of the
acoustic duct 30 is 1/1 of the wavelength λ of the acoustic wave output. As shown in FIG. 4, a
sharp dip p occurs in the sound pressure frequency characteristic of the speaker system at a
point fa of frequency 2, and when the drop of this frequency comes close to 300 to 500 cycles,
the sound emission characteristic of the bass is There is a problem of significant deterioration.
[0003]
Therefore, in place of the acoustic duct 30, as shown in FIG. 5, a bass reflex opening 40 is
provided on the front side of the housing 10, and a diaphragm 50 is attached to the bass reflex
opening 40 by an edge 60. There is known a passive radiator type bass reflex type speaker
system in which the mass and the air capacity in the housing 10 resonate to enhance the sound
10-04-2019
1
output of the bass.
[0004]
In the electrical equalization circuit of this bass reflex type speaker system, as shown in FIG. 6,
the drive signal source V is converted to the sound pressure by the electro-acoustic conversion
transformer TS via the inductances r and l of the voice coil. Simultaneously with the sound
emission output PS, the phase-reversal output PR is output from the bass reflex opening 40
through a low pass circuit consisting of the impedance L of the compliance in the housing and
the impedance C indicating the mass of the diaphragm 50. And the bass frequency is enhanced.
(The equivalent circuit is a speed-voltage conversion circuit. Note that D indicates the vibration
characteristics of the speaker as mechanical impedances r1, C1 and L1, E indicates equivalently
the mechanical impedances r2 and L2 of the edge 60 of the diaphragm 50.
[0005]
By the way, as understood from this circuit configuration, in order to obtain a bass output, the
capacity of the housing 10 is increased to increase the compliance, or a passive radiator is
obtained Although it is necessary to increase the mass of the diaphragm 50, since the capacity
can not be increased in a small speaker system, it is required to increase the mass of the passive
radiator in order to further enhance the bass output.
[0006]
However, if the mass of the passive radiator is increased, the edge 60 made of the visco-elastic
material is bent by supporting the passive radiator, and if the material of the edge is hardened to
suppress the deflection, the edge compliance Can not be ignored, and good low frequency
characteristics can not be obtained.
That is, there is a problem that the mechanical impedances r2 and L2 deteriorate the
characteristics of the phase inversion output PR. Also, at this time, noise may be generated from
the edge.
10-04-2019
2
[0007]
SUMMARY OF THE INVENTION The present invention has been made to solve the above
problems, and a mechanical-electrical conversion device is attached to a diaphragm serving as a
passive radiator, and the mechanical of the diaphragm is achieved. The mass of the diaphragm is
substantially increased by correcting the above characteristics by the electrical circuit element.
[0008]
The mass of the diaphragm can be made substantially high by taking out the movement of the
diaphragm as an electrical output and connecting a capacitive impedance to this signal output.
[0009]
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 is a cross-sectional view
showing an overview of a speaker system according to the present invention.
In this figure, reference numeral 10 denotes a closed casing, and on the front side thereof, a
speaker 20 for sound emission is attached.
A bass reflex opening 40 is provided on the front side of the housing 10 in the same manner as
in FIG. 5, and the bass reflex opening 40 is provided with a diaphragm 50 attached by an edge
60.
[0010]
Reference numeral 70 denotes a mechanical-electrical converter for converting the vibration of
the diaphragm 50 into an electrical output, and is constituted, for example, by a coil attached to
the diaphragm and a magnetic device for applying a magnetic field to the coil. When the
diaphragm vibrates, an induced voltage is generated in the coil. And the capacitor c is connected
to the output terminal.
[0011]
10-04-2019
3
FIG. 2 shows an electrical equivalent circuit of the above speaker system. As in the case of FIG. 5,
TS is a temporary transformer for converting an acoustic signal into sound pressure. D is an
equivalent circuit showing the compliance of the speaker 20, the mass of the voice coil, and the
mechanical resistance component, and P is the equivalent of the compliance of the diaphragm 50
serving as a passive radiator, the mass of the coil, and the mechanical resistance component of
the diaphragm. The circuit is shown. L shows compliance indicating an air spring component
inside the housing 10, 70 is a temporary transformer for converting the vibration of the
diaphragm 50 into an electrical signal, and shows the mechanical-electrical converter 70. A large
capacity capacitor C is connected to the next side.
[0012]
Therefore, if the compliance L of the housing 10 and the externally attached capacitor C are set
to a desired bass resonance frequency, the bass output of the speaker is improved and a bass
reflex effect is produced. In this case, the substantial mass of the diaphragm 50 may be
equivalent to that of the conventional passive radiator, and the edge supporting the diaphragm
can be made of a relatively soft material, so the influence of the edge 60 causes the sound quality
to be improved. There is nothing to lose.
[0013]
The capacitance of the externally attached capacitor C is a small speaker, which requires a
relatively large capacitance when emphasizing the bass portion. For example, as shown in (b) of
FIG. By using a capacitance multiplying circuit using a mirror circuit in which the capacitor C is
inserted into the feedback circuit A, it is possible to increase the mass of the diaphragm with a
small capacity capacitor. Further, in the circuit of FIG. 2, when the resistance VR is changed, the
output of the bass can be adjusted to have a desired characteristic.
[0014]
As described above, in the loudspeaker system of the present invention, a mechanical-electrical
converter is provided to the diaphragm which is a conventional passive radiator, and the output
terminal of the mechanical-electrical converter is provided. Since the mass of the diaphragm
serving as the passive radiator is increased by connecting the capacitive impedance elements, the
mass of the diaphragm can be substantially reduced without increasing the resistance component
10-04-2019
4
of the edge carrying the diaphragm. Can be high. Therefore, in the conventional bass reflex type
small speaker system, it is possible to further improve the output of the bass, and at the same
time, it is possible to prevent the generation of abnormal noise.
[0015]
Brief description of the drawings
[0016]
1 is a schematic diagram showing a speaker system of the present invention FIG. 2 is an
equivalent circuit diagram of the speaker system of the present invention.
[0017]
3 is an explanatory view of a conventional bass reflex speaker system.
[0018]
4 is a sound emission characteristic diagram of the speaker.
[0019]
5 is a schematic diagram of a passive radiator type speaker system.
[0020]
6 is an acoustic equivalent circuit diagram of the passive radiator system.
[0021]
Explanation of sign
[0022]
Reference Signs List 10 speaker housing 20 speaker 30 acoustic duct 40 bass reflex opening 50
diaphragm 60 edge 70 mechanical-electrical converter
10-04-2019
5
Документ
Категория
Без категории
Просмотров
0
Размер файла
13 Кб
Теги
description, jph04309098
1/--страниц
Пожаловаться на содержимое документа