JP2016504868

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DESCRIPTION JP2016504868
The present invention discloses a micro-speaker module, a method and electronic device for
enhancing its frequency response. The method is to add a passive sound source to be emitted
jointly with the active sound source in a chamber in which the active sound source of the micro
speaker module is located, and to add the passive sound source to the micro speaker module. The
amplitude of the diaphragm is such that a local valley with a minimum point F0 appears in the
frequency band below the resonance frequency point F0, and the amplitude characteristic of the
active sound source diaphragm of the micro speaker module to which the passive sound source
is added. And performing matching enhancement processing on the input signal of the active
sound source. According to the technical solution of the present invention, the frequency
response of the entire microspeaker module to which the passive sound source is added is
improved in the low frequency band below F0, and the matching enhancement process is
performed based on the amplitude characteristic of the active sound source. The frequency
response over the entire frequency band of the speaker module can be significantly improved.
[Selected figure] Figure 1
Micro-speaker module, method and electronic device for enhancing its frequency response
[0001]
The invention relates to the field of acoustics, in particular to a micro-speaker module, a method
and electronic device for enhancing its frequency response.
[0002]
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1
At present, in the field of communication acoustics and mobile devices (for example, mobile
phones, tablet PCs, notebook computers, etc.), most of the micro moving coil speaker modules
adopt a closed back chamber design, The acoustic drive component is encased in a case and the
entire back chamber of the speaker module is sealed.
Due to back chamber size and product volume limitations, the low frequency resonant point F0
of the micro speaker module is high and can not provide a sufficiently low low frequency dive.
The equalizers involved (EQ, equalizer) and the bass boost algorithm are both based on the
design of this type of closed box micro speaker module, but in the frequency band below F 0 the
amplitude and element size of the existing diaphragm It is not possible to realize true physical
low frequency dives.
[0003]
In order to solve the problem that the existing micro-speaker module can not provide a
sufficiently low frequency dive and the lack of loudness, the present invention provides a method
of enhancing the frequency response of the micro-speaker module, a micro-speaker module and
electronic Provide an apparatus.
[0004]
In order to achieve the above object, the technical solution of the present invention is realized as
follows.
[0005]
A method of enhancing the frequency response of the micro speaker module disclosed in the
present invention is to add a passive sound source that emits jointly with the active sound source
in a chamber in which the active sound source of the micro speaker module is located, After
adding a passive sound source in the micro speaker module, the amplitude of the diaphragm of
the active sound source is such that a local valley whose minimum point is the frequency point
Fb appears in a frequency band below the resonance frequency point F0; Performing matching
enhancement processing on the input signal of the active sound source based on the amplitude
characteristic of the diaphragm of the active sound source of the micro speaker module to which
the passive sound source is added.
[0006]
The micro speaker module is a frontal sounding design, and the passive sound source and the
active sound source respectively radiate independently, or the micro speaker module is a frontal
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sounding design, and the passive sound source and the active sound source are Preferably, the
micro-speaker module shares the front chamber and emits jointly, or the micro-speaker module
has a side sounding design, and the passive sound source and the active sound source share the
front chamber.
[0007]
The matching enhancement process is performed on the input signal of the active sound source
based on the amplitude characteristic of the diaphragm of the active sound source of the micro
speaker module to which the passive sound source is added, the first frequency point being a
frequency point lower than Fb. Filtering out the following signals to filter out the signals whose
amplitude in the frequency band below Fb exceeds the tolerance of the diaphragm of the active
sound source, and a constant frequency with Fb as the center frequency point Band pass filtering
is performed on signals in the band and enhancement processing is performed to realize low
frequency dive and bass boost, and to signals in a certain frequency band having F0 as a center
frequency point Vibration of the active sound source diaphragm near F 0 by notch filtering The
characteristic that the diaphragm of the active sound source has a small amplitude in the middle
and high frequency band while performing high pass filtering on a signal higher than F 0 and
performing high pass filtering on a signal of a second frequency point or higher higher than F 0
Preferably enhancing the medium to high frequency response.
[0008]
The method adjusts Fb by changing the modulus of elasticity of the passive sound source and /
or adjusts F0 by changing the nature of the diaphragm of the active sound source and the quality
of the voice coil, the values of Fb and F0, and Adjusting any one or more of the filter Q, order,
frequency band attenuation parameters, and cutoff frequency parameters in the matching
enhancement process based on the characteristics of the power amplifier and diaphragm
amplitude. It is preferable to include.
[0009]
The invention further discloses a micro-speaker module, which comprises a chamber, an active
sound source installed in the chamber, and further comprises a passive sound source and a
matching enhancement unit, said passive sound source comprising The amplitude of the
diaphragm of the active sound source after being installed in the chamber in which the active
sound source is located and emitting jointly with the active sound source and adding a passive
sound source in the micro speaker module is a frequency band below the resonance frequency
point F0 , The local valley whose minimum point is the frequency point Fb appears, and the
matching enhancement unit inputs the active sound source based on the amplitude characteristic
of the active sound source diaphragm of the micro speaker module to which the passive sound
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source is added. Perform matching enhancement on the signal Used for
[0010]
The micro speaker module is a frontal sounding design, and the passive sound source and the
active sound source respectively radiate independently, or the micro speaker module is a frontal
sounding design, and the passive sound source and the active sound source are Preferably, the
micro-speaker module shares the front chamber and radiates jointly, or the micro-speaker
module has a side sounding design, and the passive sound source and the active sound source
share the front chamber.
[0011]
The matching enhancement unit filters out signals below the first frequency point, which is a
frequency point lower than Fb, to remove signals whose amplitude in the frequency band below
Fb exceeds the tolerance of the diaphragm of the active sound source. Low-frequency dive and
bass boost by performing band-pass filtering on a signal within a certain frequency band with Fb
as the center frequency point and performing enhancement processing on an ultra-low-frequency
filter unit that filters out and removes A low frequency enhancement unit to be realized and
notch filtering for signals within a certain frequency band centering on F0 as a center frequency
point prevent the amplitude of the active sound source diaphragm from becoming excessive in
the vicinity of F0. Frequency reduction unit and high-pass filter for signals above the second
frequency point above Performs Taringu, performs amplification processing, the characteristic
that the amplitude is small in the middle and high frequency band of the active source diaphragm
preferably includes a high frequency enhancing units to enhance the middle and high frequency
response, the.
[0012]
Adjust Fb by changing the elastic modulus of the passive sound source, and / or adjust F0 by
changing the nature of the active sound source diaphragm and voice coil, and the values of Fb
and F0 and the system power amplifier It is preferable to adjust any one or more parameters of
the filter Q value, order, frequency band attenuation parameter, and cutoff frequency in the
matching enhancement process based on the amplitude characteristics of the diaphragm.
[0013]
The invention further discloses an electronic device, which comprises the microspeaker
according to any one of the above mentioned.
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Preferably, the electronic device is a mobile phone, a tablet PC, a tablet television or a laptop
computer.
[0014]
In the present invention, in the chamber in which the active sound source of the micro speaker
module is located, a passive sound source to be emitted jointly with the active sound source is
added.
After adding a passive sound source to the micro speaker module, the amplitude of the
diaphragm of the active sound source has a local valley in which the minimum point is the
frequency point Fb in the frequency band below the resonance frequency point F0.
The matching enhancement process is performed on the input signal of the active sound source
based on the amplitude characteristic of the diaphragm of the active sound source of the micro
speaker module to which the passive sound source is added.
In such a technical solution, the frequency response of the entire micro speaker module to which
the passive sound source is added is improved in the frequency band below F0, and the matching
enhancement process is performed based on the amplitude characteristic of the active sound
source. The frequency response across the entire frequency band can be significantly improved.
[0015]
Flow chart of a method of enhancing the frequency response of the micro speaker module in an
embodiment of the present invention. Schematic diagram of a micro speaker module having a
passive sound source structure in an embodiment of the present invention. Micro speaker
module having a passive sound source structure in an embodiment of the present invention Of
the frequency response curve of the micro speaker module with the conventional closed box
design and the impedance curve of the micro speaker module having the passive sound source
structure and the micro speaker module of the conventional closed box design in one
embodiment of the present invention Schematic diagram Comparison of amplitude curves of a
micro speaker module having a passive sound source structure according to an embodiment of
the present invention and a micro speaker module having a conventional closed box design A
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passive according to an embodiment of the present invention Schematic diagram of matching
enhancement processing algorithm designed for the amplitude characteristics shown in FIG. 5 of
the micro speaker module having source structure. Micro speaker module having passive sound
source structure designed based on FIG. 6 in one embodiment of the present invention Schematic
diagram of matching enhancement processing algorithm for a specific embodiment of matching
enhancement processing algorithm in different frequency bands for a micro speaker module
having a passive sound source structure designed based on FIGS. 6 and 7 in one embodiment of
the present invention Schematic diagram A schematic view of a micro speaker module having a
passive sound source structure according to another embodiment of the present invention A
schematic diagram of a micro speaker module having a passive source structure according to
another embodiment of the present invention Schematic diagram of the structure of the micro
speaker module Schematic of structure of strong unit 1104
[0016]
In order to make the objectives, technical solutions and advantages of the present invention
clearer, embodiments of the present invention will be described in more detail with reference to
the drawings.
[0017]
FIG. 1 is a flow chart of a method of enhancing the frequency response of a micro speaker
module in an embodiment of the present invention.
As shown in FIG. 1, the method includes steps 101 and 102. In step 101, a passive sound source
jointly emitting with the active sound source is added in a chamber in which the active sound
source of the micro speaker module is located.
[0018]
Here, by adding a passive sound source in the chamber where the active sound source of the
micro speaker module is located, when the active sound source is operating, the diaphragm of
the active sound source pushes out the air in the chamber and the inside of the chamber Air
pushes the diaphragm of the passive sound source to vibrate to generate a second sound source
signal, and the second sound source signal jointly radiates with the active sound source signal to
improve the low frequency response of the speaker it can.
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After adding a passive sound source in the micro speaker module, the amplitude of the
diaphragm of the active sound source is such that a local valley corresponding to the frequency
point Fb appears in the frequency band below the resonance frequency point F0.
[0019]
In step 102, matching enhancement processing is performed on the input signal of the active
sound source based on the amplitude characteristic of the diaphragm of the active sound source
of the micro speaker module to which the passive sound source is added.
[0020]
In the method shown in FIG. 1, the micro speaker module in which the passive sound source is
designed can improve the frequency response of the micro speaker module in the frequency
band lower than F 0 by additionally providing the passive sound source, and the matching
enhancement processing is further performed. The frequency response of the entire microspeaker module's frequency band will all be greatly improved.
The method shown in FIG. 1 effectively enhances the low frequency response of the
microspeaker module and provides sufficient low frequency dive and loudness to the microelectroacoustics field such as mobile phones, tablet PCs, televisions and It can be widely applied
to notebook computers and the like.
[0021]
FIG. 2 is a schematic view of a micro speaker module having a passive sound source structure
according to an embodiment of the present invention.
Referring to FIG. 2, in one embodiment of the present invention, a passive sound source 203 is
added to the chamber 201 where the active sound source 202 of the micro speaker module is
located based on the method shown in FIG.
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In the present embodiment, the micro-speaker module is a frontal sound design, and the passive
sound source 203 and the active sound source 202 radiate independently.
Specifically, the passive sound source 203 is installed at a position away from the active sound
source 202 in the chamber 201 by a prescribed distance, and the direction in which the passive
sound source 203 and the active sound source 202 emit sounds is the same. The sound output
port 205 and the sound output port 206 are respectively installed at front positions of the
passive sound source 203 and the active sound source 202.
The audio chip 204 for realizing the enhancement process performs the matching enhancement
process on the signal input to the active sound source 202.
[0022]
FIG. 3 is a schematic comparison of frequency response curves of a micro speaker module having
a passive sound source structure according to an embodiment of the present invention and a
micro speaker module having a conventional closed box design.
FIG. 3 is a comparative schematic view of typical frequency response curves of a micro speaker
module having a passive sound source structure designed according to the method described in
FIG. 1 and a micro speaker module having a conventional closed box design, The solid line is the
frequency response curve of the micro speaker module having the passive sound source
structure, and the dotted line is the frequency response curve of the micro speaker module of the
conventional closed box design.
Referring to FIG. 3, when no matching enhancement process is added, the low frequency
sensitivity of the micro speaker module having the passive sound source structure is improved to
some extent over the micro speaker module of the conventional closed box design.
[0023]
FIG. 4 is a schematic comparison diagram of impedance curves of a micro speaker module having
a passive sound source structure according to an embodiment of the present invention and a
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micro speaker module having a conventional closed box design. In FIG. 4, the solid line is the
impedance curve of the micro speaker module having a passive sound source structure, and the
dotted line is the impedance curve of the micro speaker module of the conventional closed box
design. As clearly shown in FIG. 4, the amplitude of the voice coil is limited by the radiation of the
passive sound source in the low frequency band because the micro speaker module having the
passive sound source structure has a local low point in the impedance curve (in this embodiment
It is around 350 Hz, and the 350 Hz frequency point is called Fb).
[0024]
FIG. 5 is a schematic comparison diagram of amplitude curves of a micro speaker module having
a passive sound source structure according to an embodiment of the present invention and a
micro speaker module having a conventional closed box design. Referring to FIG. 5, the dashed
line shows the amplitude curve of the micro speaker module of the conventional closed box
design, the solid line shows the amplitude curve of the active sound source of the micro speaker
module having the passive sound source structure in the present invention, and the dotted line
shows the amplitude in the present invention. It is an amplitude curve of the passive sound
source of the micro speaker module which has a passive sound source structure. As can be seen
from FIG. 5, the oscillation width of the active sound source indicated by the solid line is the local
minimum point Fb of the amplitude in the frequency band below the resonance point F0 (in the
present embodiment, F0 is a frequency point near 700 Hz, Fb There are 350 Hz frequency
points). That is, Fb is a frequency point where the amplitude of the active sound source of the
micro speaker module to which the passive sound source is added corresponds to the minimum
point of the amplitude below the resonance point F0.
[0025]
For the feature shown in FIG. 5, the match enhancement algorithm shown in FIG. 6 is designed in
an embodiment of the present invention.
[0026]
FIG. 6 is a schematic diagram of a matching enhancement processing algorithm designed for the
amplitude characteristic shown in FIG. 5 of the micro-speaker module having a passive sound
source structure according to an embodiment of the present invention.
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Referring to FIG. 6, specifically, the matching enhancement processing algorithm includes the
following steps S1, S2, S3, and S4.
[0027]
In step S1, by filtering out signals below the first frequency point lower than Fb, a signal whose
amplitude in the frequency band below Fb exceeds the tolerance of the diaphragm of the active
sound source (250 Hz or less in this embodiment) Filter out).
[0028]
Here, a signal below the first frequency point is referred to as an extremely low frequency signal,
and the amplitude of the diaphragm in this frequency band is large, exceeding the tolerance of
the diaphragm of the active sound source (approaching / reaching / exceeding the tolerance of
the diaphragm To point out).
In filtering out very low frequency signals, it is common practice to use a high pass filter, and the
filter cutoff frequency is determined by the amplitude curve of the active sound source
diaphragm and the nature of the diaphragm itself. For example, the first frequency point is a
frequency point at which the amplitude curve of the active sound source of the micro speaker
module having a passive sound source structure has a filter cut-off frequency as the first
frequency point and lower than Fb and reaches the diaphragm tolerance. A filter cutoff frequency
can be selected.
[0029]
In step S2, low-frequency dive and bass boost are realized by performing band pass filtering on a
signal in a certain frequency band having Fb as a center frequency point and performing
enhancement processing.
[0030]
Here, the signal in this frequency band can be enhanced by making full use of the feature that
the amplitude valley of the diaphragm appears in the Fb band, thereby realizing low frequency
dive and bass boost, among which Fb is a frequency point at which the amplitude of the active
sound source of the micro-speaker module to which the passive sound source is added is the
minimum point in the low frequency band below F0 (in this embodiment, Fb is 350 Hz). The
constant frequency band as the frequency point is determined by the amplitude curve of the
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active sound source of the micro speaker module having a prescribed threshold value and the
passive sound source structure. For example, the amplitude curve of the active sound source of
the micro speaker module having the passive sound source structure Is a prescribed threshold
(the threshold is set as required, for example, 60% of the allowable diaphragm width) Can be
selected for two frequency point when reaching the can) be 70% as two end points of the
frequency band.
[0031]
In step S3, notch filtering is performed on a signal within a certain frequency band having F0 as
a center frequency point to prevent the amplitude of the diaphragm of the active sound source
from becoming excessive around F0.
[0032]
The amplitude of the diaphragm in the vicinity of F0 is large and should not be over-enhanced
during processing, so notch filtering is performed here to prevent the amplitude from becoming
excessive.
Among them, F0 is a low frequency resonance point of the micro speaker module to which a
passive sound source is added (in this embodiment, F0 is 700 Hz).
The constant frequency band having the center frequency point of F0 described above is
determined by the amplitude curve of the active sound source of the micro speaker module
having a prescribed threshold value and a passive sound source structure, for example, of the
micro speaker module having a passive sound source structure. Two frequency points at which
the amplitude curve of the active sound source reaches a prescribed threshold (the threshold
may be set as required, for example, 40% or 60% of the diaphragm allowable width) may be two
frequency bands. It is selectable as an end point.
[0033]
In step S4, high-pass filtering is performed on signals above the second frequency point higher
than F0 and enhancement processing is performed, and the diaphragm of the active sound
source has a small amplitude in the middle to high frequency band, so that middle to high
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frequency response is obtained. To strengthen.
The second frequency point is a frequency point higher than F0, and it is understood from the
characteristics of amplitude that the amplitude of the diaphragm decreases with an increase in
frequency if the frequency is higher than F0, and thus the second higher than F0 The amplitude
of the diaphragm corresponding to the frequency higher than the second frequency point can be
selected (the threshold is set as needed, for example, 20% or 30% of the allowable diaphragm
width). Or, it can be made smaller than 40%, and high-pass filtering can be performed on a signal
whose frequency is higher than the second frequency point, and enhancement processing can
enhance middle-to-high frequency response.
[0034]
Since the amplitude in the high frequency band is small, the frequency response of the entire
system can be greatly improved by performing enhancement processing on the high frequency
signal here.
[0035]
FIG. 7 is a schematic diagram of a matching enhancement processing method for a micro speaker
module having a passive sound source structure designed based on FIG. 6 according to an
embodiment of the present invention.
Referring to FIG. 7, filtering processing of an ultra-low frequency signal, enhancement filtering
processing in a frequency band near Fb, sequentially to a signal input to an active sound source
of a micro speaker module having a passive sound source structure of the present invention, F0
Notch filtering processing in a nearby frequency band and filtering enhancement processing in a
high frequency band are performed. It is worth noting that the steps of the four blocks shown in
FIG. 7 are not limited to the order currently shown in FIG. 7, and in other embodiments of the
invention, the steps of these four blocks are in any order. It can be carried out.
[0036]
It is possible to adjust Fb by changing the elastic coefficient of the passive sound source, and
adjust F0 by changing the nature of the diaphragm of the active sound source and the quality of
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the voice coil. And one or more parameters of Q factor, order, frequency band attenuation
parameter, and cutoff frequency in the matching enhancement process based on the values of Fb
and F0 and the characteristics of the power amplifier and diaphragm amplitude. Can be adjusted.
[0037]
There are various implementation schemes for the matching enhancement processing and
filtering amplification scheme in the present invention. It can be implemented in software or
hardware, and can be implemented in analog or digital signals. However, the core frame of the
implementation should be matched with the portion of FIGS. 6 and 7 where Fb is the center bass
boost, in particular.
[0038]
FIG. 8 is a schematic diagram of specific processing in different frequency bands of the matching
enhancement processing algorithm for the micro speaker module having a passive sound source
structure designed based on FIGS. 6 and 7 in one embodiment of the present invention. .
Referring to FIG. 8, in the present embodiment, the algorithm of the matching enhancement
process is specifically as follows.
[0039]
By filtering out signals below the F1 frequency point, signals that cause the amplitude in the
frequency band below Fb to exceed the tolerance of the diaphragm of the active sound source are
filtered out. The F1 frequency point is a frequency point when the amplitude curve of the active
sound source of the micro speaker module having the passive sound source structure reaches the
diaphragm allowable width.
[0040]
Band pass filtering is performed on a signal within a certain frequency band whose center
frequency point is Fb, and enhancement processing is performed. The signal in the constant
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frequency band is a signal in the F2 to F3 frequency band. The F2 and F3 frequency points
respectively become two frequency points when the amplitude curve of the active sound source
of the micro speaker module having the passive sound source structure reaches a predetermined
threshold.
[0041]
Notch filtering is performed on a signal in a certain frequency band whose center frequency
point is F0, and a signal in the certain frequency band is a signal in the F3 to F4 frequency band.
The F3 and F4 frequency points are respectively two frequency points when the amplitude curve
of the active sound source of the micro speaker module having the passive sound source
structure reaches a predetermined threshold.
[0042]
High-pass filtering is performed on frequency signals higher than the F4 frequency point and
enhancement processing is performed. The amplitude of the diaphragm corresponding to
frequencies above the F4 frequency point is less than one defined threshold.
[0043]
Among them, F1 <F2 <Fb <F3 <F0, and specific values of Fb, F0, F1, F2, F3 and F4 are
determined by specific parameters of the passive speaker design micro speaker module. Be
[0044]
For example, it is possible to adjust Fb by changing the elastic coefficient of the passive sound
source, and to adjust F0 by changing the nature of the diaphragm of the active sound source and
the quality of the voice coil. The parameters such as and the cut-off frequency can be determined
by the person skilled in the art according to the actual demand and the existing parameters of
the microspeaker module (such as amplifier performance, loudspeaker diaphragm and voice coil
properties) at the same time The upper limit of the algorithmic compensation can be adjusted in
consideration of the electrical and mechanical performance of the system as a whole to prevent
damage to the active member due to overdrive, so it will not be described in detail here.
[0045]
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In the present invention, the design of the micro speaker module having a passive sound source
structure is not limited to the structure shown in FIG. 2, and in the other embodiments of the
present invention, there are various other realization methods. There is something to show.
[0046]
FIG. 9 is a schematic view of a micro speaker module having a passive sound source structure
according to another embodiment of the present invention.
Referring to FIG. 9, in the present embodiment, the micro-speaker module has a frontal sounding
design, and the passive sound source and the active sound source share the front chamber and
emit jointly.
Specifically, the passive sound source 903 is installed at a position adjacent to the active sound
source 902 in the chamber 901 of the micro speaker module, and the directions of the passive
sound source 903 and the active sound source 902 to emit the sound are the same. The common
sound output port 904 is installed at the front position of the passive sound source 903 and the
active sound source 902.
[0047]
FIG. 10 is a schematic view of a micro speaker module having a passive sound source structure
according to another embodiment of the present invention.
Referring to FIG. 10, in the present embodiment, the micro-speaker module has a side sounding
design, and the passive sound source and the active sound source share a front chamber.
Specifically, the passive sound source 1003 is installed at a position adjacent to the active sound
source 1002 in the chamber 1001 of the micro speaker module, and the passive sound source
1003 has a direction of emitting sound orthogonal to the active sound source 1002 and the
passive sound source of the chamber 1001 Although the sound output port 1004 is installed at
the front position of 1003, the sound output port is not installed at the front position of the
active sound source 1002.
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[0048]
FIG. 9 is a frontal sounding design, where the proximity of the passive source to the active source
helps with the high frequency response of the system. FIG. 10 shows a side sounding design.
Sharing of the front chamber between the passive sound source and the active sound source
helps to make the structure compact and reduce the weight of the system. In another
embodiment of the present invention, the position of the passive sound source can be flexibly
selected according to the situation of the system.
[0049]
What I would like to explain is that in FIGS. 2, 9 and 10, the outer peripheral frame of the active
sound source (ie, the outer peripheral frame of the horn shape) indicates the position of the
active sound source. There should be no enclosure or other interpretation outside.
[0050]
FIG. 11 is a schematic view of a structure of a micro speaker module according to another
embodiment of the present invention.
Referring to FIG. 11, the micro-speaker module includes a chamber 1101 and an active sound
source 1102 disposed in the chamber, and the micro-speaker module further includes a passive
sound source 1103 and a matching enhancement unit 1104.
[0051]
The passive sound source 1103 is installed in the chamber 1101 in which the active sound
source 1102 is located, and the passive sound source 1103 emits jointly with the active sound
source 1102. When the active sound source 1102 is operating, the diaphragm of the active
sound source pushes out the air in the chamber 1101, and the air in the chamber 1101 pushes
and vibrates the diaphragm of the passive sound source to generate a second sound source
signal The co-emission of the second source signal with the active source can improve the low
frequency response of the speaker. After adding the passive sound source 1103 in the micro
speaker module, the amplitude of the diaphragm of the active sound source 1102 is such that a
local valley appears in a frequency band lower than the resonance frequency point F0 and the
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minimum point of the local valley is It corresponds to the Fb frequency point.
[0052]
The matching enhancement unit 1104 performs matching enhancement processing on the signal
input to the active sound source based on the amplitude characteristic of the diaphragm of the
active sound source of the micro speaker module to which the passive sound source is added.
[0053]
In one embodiment of the present invention, the micro-speaker module is a frontal sounding
design, and the passive and active sources emit independently.
Specifically, refer to FIG.
[0054]
In one embodiment of the present invention, the micro-speaker module is a frontal sounding
design, and the passive and active sound sources share the front chamber and radiate jointly.
Specifically, refer to FIG.
[0055]
In one embodiment of the present invention, the micro-speaker module is a side sounding design,
and the passive sound source and the active sound source share a front chamber. Specifically,
refer to FIG.
[0056]
FIG. 12 is a schematic view of the structure of the matching enhancement unit 1104 in FIG.
Referring to FIG. 12, matching enhancement unit 1104 includes an ultra low frequency filter unit
1141, a low frequency enhancement unit 1142, a low frequency reduction unit 1143 and a high
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frequency enhancement unit 1144.
[0057]
The very low frequency filter unit 1141 filters out signals below the first frequency point, which
is a frequency point lower than Fb, so that the amplitude in the frequency band below Fb exceeds
the tolerance of the diaphragm of the active sound source. Filter out the signal.
[0058]
The low frequency enhancement unit 1142 performs low pass dive and bass boost by performing
band pass filtering on a signal within a certain frequency band having Fb as a center frequency
point and performing enhancement processing.
[0059]
The low frequency reduction unit 1143 performs notch filtering on a signal within a certain
frequency band having the center frequency point F0, thereby preventing the amplitude of the
diaphragm of the active sound source from becoming excessive in the vicinity of F0.
[0060]
The high frequency enhancement unit 1144 performs high-pass filtering and enhancement
processing on signals higher than the second frequency point higher than F 0, and has a
characteristic that the amplitude in the middle and high frequency band of the diaphragm of the
active sound source is small. Enhance the response.
[0061]
It should be noted that the four units in the alignment enhancement unit may be arranged in any
order.
The matching enhancement unit can be implemented not only by software but also by hardware.
[0062]
In one embodiment of the present invention, for the micro-speaker module shown in FIG. 11, Fb
is adjusted by changing the elastic coefficient of the passive sound source, and / or the
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diaphragm property of the active sound source and the quality of the voice coil are changed.
Adjust the F0, and based on the values of Fb and F0 and the characteristics of the system power
amplifier and diaphragm amplitude, in the match enhancement process, filter Q factor, order,
frequency band attenuation parameters and cutoff frequency Adjust any parameter or
parameters.
[0063]
In one embodiment of the present invention, a further type of electronic device is disclosed,
which comprises a micro-speaker module having a passive sound source structure as described
in any of the previous embodiments.
The electronic device is a mobile phone, a tablet PC, a tablet TV or a laptop computer.
[0064]
To summarize the above, in the present invention, a passive sound source is added in the
chamber in which the active sound source of the micro speaker module is located.
The passive sound source jointly radiates with the active sound source, and after adding the
passive sound source to the micro speaker module, the amplitude of the diaphragm of the active
sound source has a local valley in a frequency band below the resonance frequency point F0.
The local valley minimum corresponds to the Fb frequency point.
The matching enhancement process is performed on the input signal of the active sound source
based on the amplitude characteristic of the diaphragm of the active sound source of the micro
speaker module to which the passive sound source is added. In such a technical solution, the
frequency response of the entire micro speaker module enhanced with the passive sound source
is improved in the frequency band below F0, and the matching enhancement process is further
performed, so that the frequency response in the entire frequency band of the micro speaker
module Can be significantly improved.
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[0065]
The above description is just a preferred embodiment of the present invention, and the
protection scope of the present invention is not limited to this. Any changes, replacements,
improvements, etc. made in accordance with the spirit and principle of the present invention
should be included in the protection scope of the present invention.
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