JPH11146485A - Speaker system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a speaker system that can raise a sound pressure level at a low-frequency range by specifying an impedance of an impedance compensation circuit. SOLUTION: An impedance compensation circuit of an impedance Zc, which turns an electric impedance of a speaker system into a constant-resistance in order to prevent a decline of efficiency, is inserted serially in the second voice coil. At this time, the impedance compensation circuit decides the impedance Zc so that the electric impedance as the speaker system becomes the constant-resistance when a passive radiator system cabinet is used. That is, this impedance compensation circuit becomes what an equation indicates in a formulaic expression. In the equation, each of L1 and L2 indicates inductance and each of C1 and C3 indicates capacity and each of rc1 and rc2 indicates resistance.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a case where a cabinet is of a passive radiator type or a Kelton type provided with a passive radiator, the electrical impedance of a speaker system is made to have a constant resistance, and as a result, a sound pressure level in a low frequency range is increased. The present invention relates to a speaker system that can be operated.

That is, the present invention relates to a speaker system including a passive radiator type cabinet, a double voice coil speaker unit, and an impedance compensation circuit for making the input impedance constant, or a Kelton type having a passive radiator. The present invention relates to a speaker system including a cabinet, a double voice coil speaker unit, and an impedance compensation circuit for making input impedance constant.

[0003]

2. Description of the Related Art A conventional speaker system will be described with reference to FIGS. 7, 8 and 9. FIG. FIG. 7 is disclosed, for example, by Watkins (WH Watkins "N
ew Loudspeaker with Extended Bass ”Audio, Dec. 19
74, pp. 38-46) A configuration example of a conventional speaker system in which a double voice coil is used to improve sound radiation efficiency in a low frequency range.

In FIG. 7, reference numerals 11 and 12 denote signal input terminals to a speaker, reference numeral 20 denotes a double voice coil speaker unit, reference numeral 21 denotes a first voice coil, reference numeral 22 denotes a second voice coil, and reference numeral 23 denotes a voice coil. The bobbin 30 is an impedance compensation circuit for making the electrical impedance of the speaker system constant.

Next, the operation of the conventional speaker system will be described with reference to FIGS. FIG.
FIG. 3 is a diagram showing an electrical impedance characteristic of a conventional speaker system. FIG. 9 is a diagram showing sound pressure level characteristics of a conventional speaker system.

Generally, when the impedance compensation circuit 30 is not provided, that is, when only the first voice coil 21 is used, the electric impedance of the speaker unit 20 becomes a parallel resonance circuit, and as shown in FIG. ) Of the lowest resonance frequency f ₀
A characteristic peak occurs in the vicinity.

Therefore, the current flowing through the first voice coil 21 decreases near the lowest resonance frequency f ₀ , and the efficiency of sound radiated from the speaker decreases.

In FIG. 7, a series circuit composed of a coil L and a capacitor C is inserted in series into the second voice coil 22.
The electric impedance is always constant (constant resistance) by connecting a series resonance circuit to which the resistance of the second voice coil 22 is added in parallel with the first voice coil 21.
To improve sound radiation efficiency.

FIG. 9 shows a change in the sound pressure level depending on the presence or absence of the impedance compensating circuit in a low sound range. As can be seen from FIG.
By increasing the impedance to a constant resistance using, a rise in sound pressure level near the lowest resonance frequency f ₀ , that is, a rise in sound radiation efficiency can be seen. This magnitude can reach several dB depending on conditions.

[0010]

In the conventional speaker system described above, the impedance compensation circuit 30 is used.
Is constituted by a series resonance circuit including a coil L, a capacitor C, and a resistance of the second voice coil 22, the constant resistance can be realized because the electric impedance of the first voice coil 21 is different from that of the parallel resonance circuit. Only if it becomes. In other words, the playback system is limited to a closed cabinet or a system in which a speaker unit is used alone. Therefore, the conventional speaker system shown in FIG. 7 has a problem that it cannot be applied to a passive ejector type cabinet or other types.

SUMMARY OF THE INVENTION The present invention has been made to solve the above-mentioned problem. When the cabinet is of a passive radiator type or a Kelton type with a passive radiator, the electrical impedance of the speaker system is made to be a constant resistance. As a result, it is an object of the present invention to obtain a speaker system capable of increasing a sound pressure level in a low frequency range.

[0012]

A speaker system according to the present invention is a dual voice coil speaker unit having a passive ejector type cabinet, and first and second voice coils attached to the cabinet and to which an input signal is applied. A passive radiator attached to the cabinet, and an impedance compensation circuit inserted between the input terminal to which the input signal is applied and the second voice coil to make the input impedance constant. When the inductances as circuit elements of the impedance compensation circuit are L ₁ and L ₂ , the capacitances are C ₁ , C ₂ and C ₃ , and the resistances are r _C1 and r _{C 2} ,
The impedance Zc of the impedance compensating circuit is represented by Expression (1).

Further, in the speaker system according to the present invention, a resonance angular frequency of the double voice coil speaker unit is ω ₀ , an equivalent mass of the double voice coil speaker unit is m ₀ , The equivalent mechanical compliance is C ₀ , the electrical sharpness of the double voice coil speaker unit is Q ₀ , the mechanical sharpness of the double voice coil speaker unit is Q _m , and the second voice coil speaker unit is the second voice coil speaker unit. the ratio of the force factor of the voice coil alpha, compliance of air by volume of the passive radiator type cabinet C _b, the passive radiator system volume by equivalent mechanical resistance r _b in the cabinet, the passive viewed from the speaker unit The equivalent mass of the radiator is m _p , the speaker The equivalent mechanical compliance of the passive radiator viewed from the speaker unit is C _p , the equivalent mechanical resistance of the passive radiator viewed from the speaker unit is r _p , the resistance of the first voice coil is R _V1 , and the second voice coil is the resistor is taken as R _{V2 is, β = m p / m 0} , γ b = C b / C 0, γ p = C p / C 0,
_{Q b = ω 0 m 0 /} r b, Q p = ω 0 m 0 / a r _p as a condition, a constant of each circuit element of the resistor R _V2 and the impedance compensation circuit of the second voice coil formula (3 ) To Expression (10)
This is the relationship.

The speaker system according to the present invention comprises a passive ejector type cabinet and first and second cabinets attached to the cabinet and to which an input signal is applied.
A double voice coil speaker unit having a voice coil, a passive radiator attached to the cabinet, and an input terminal to which the input signal is applied to make the input impedance constant, and the second voice coil. And an impedance compensating circuit inserted between the impedance compensating circuits. When the inductances as circuit elements of the impedance compensating circuit are L ₁ and L ₂ and the capacitances are C ₁ , C ₂ and C ₃ , the impedance Zc Is represented by equation (2).

A speaker system according to the present invention includes a Kelton type cabinet, a double voice coil speaker unit having first and second voice coils attached to the cabinet and to which an input signal is applied.
A passive radiator attached to the cabinet, and an impedance compensation circuit inserted between the input terminal to which the input signal is applied and the second voice coil to make the input impedance constant resistance,
When the inductances, which are the circuit elements of the impedance compensation circuit, are L ₁ and L ₂ , the capacitances are C ₁ , C ₂ , C ₃ , and the resistances are r _C1 and r _C2 , the impedance Zc of the impedance compensation circuit is expressed by the following equation (1). ).

Further, in the speaker system according to the present invention, the resonance angle frequency of the double voice coil speaker unit is ω ₀ , the equivalent mass of the double voice coil speaker unit is m ₀ , The equivalent mechanical compliance is C ₀ , the electrical sharpness of the double voice coil speaker unit is Q ₀ , the mechanical sharpness of the double voice coil speaker unit is Q _m , and the second voice coil speaker unit is the second voice coil speaker unit. the ratio of the force factor of the voice coil alpha, the double voice coil speaker equivalent mechanical compliance of C _b by the rear space of the unit, the equivalent mechanical resistance due to the air chamber in the rear space of the double voice coil speaker units r _b, Equivalent mechanical coil due to the front air chamber of the double voice coil speaker unit The compliance is C _f , 2
Equivalent mechanical resistance r _f by the front air chamber of heavy voice coil speaker unit, an equivalent mass m _p of the passive radiator as seen from the double voice coil speaker unit, the passive viewed from the double voice coil speaker unit The equivalent mechanical compliance of the radiator is C _p , the equivalent mechanical resistance of the passive radiator viewed from the double voice coil speaker unit is r _p , the resistance of the first voice coil is R _V1 , and the resistance of the second voice coil is Is R _V2 , β = m _p / m ₀ , γ
_{b = C b / C 0,} γ f = C f / C 0, γ p = C p / C 0, Q b = ω
_{0 m 0 / r b, Q} f = ω 0 m 0 / r f, Q p = ω 0 m 0 / r p on condition, the circuit of a resistor R _V2 and the impedance compensation circuit of the second voice coil The element constant is given by the equation (1)
6) to (23).

A speaker system according to the present invention includes a Kelton type cabinet, a double voice coil speaker unit having first and second voice coils attached to the cabinet and to which an input signal is applied.
A passive radiator attached to the cabinet, and an impedance compensation circuit inserted between the input terminal to which the input signal is applied and the second voice coil to make the input impedance constant resistance,
When the inductances of the circuit elements of the impedance compensation circuit are L ₁ and L ₂ and the capacitances are C ₁ , C ₂ and C ₃ , the impedance Zc of the impedance compensation circuit is
Is represented by equation (2).

Furthermore, the speaker system according to the present invention, wherein the impedance compensation circuit comprises: a first series circuit of the inductance L ₁ and the capacitor C _1, is connected to the first series circuit, a resistor r _C1 resistance to a second series circuit of the capacitor C ₂ r _C2 and the capacitor C ₃ and the third inductance L ₂
And a parallel circuit connected in parallel.

Further, in the speaker system according to the present invention, the impedance compensation circuit is connected to the first series circuit having the inductance L ₁ and the capacitance C ₁ and the capacitance C ₃ . in which capacity C ₂ in the second series circuit of the inductance L ₂ is composed of a parallel-connected parallel circuit.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiment 1 FIGS. 1 to 5 show a speaker system according to Embodiment 1 of the present invention.
This will be described with reference to FIG. FIG. 1 is a diagram showing a configuration of a speaker system according to Embodiment 1 of the present invention. In the drawings, the same reference numerals indicate the same or corresponding parts.

In FIG. 1, reference numerals 11 and 12 denote signal input terminals to speakers, reference numeral 20 denotes a double voice coil speaker unit, reference numeral 21 denotes a first voice coil, reference numeral 22 denotes a second voice coil, and reference numeral 23 denotes a voice coil. Bobbin 30A is an impedance compensating circuit for making the electrical impedance of the speaker system a constant resistance;
Is a passive ejector and 100 is a passive ejector type cabinet.

Here, the "passive radiator-type cabinet" refers to a cabinet 100 having a structure in which the rear space of the speaker unit 20 is acoustically coupled to a passive radiator 40 for emitting sound to the outside, as shown in FIG.
That is.

Next, the operation of the first embodiment will be described with reference to FIGS. FIG. 2 is a diagram showing electric impedance characteristics of the passive ejector type speaker system according to Embodiment 1 of the present invention.

[0024] Conventionally, the electrical impedance of the passive La Jay data type speaker system results in generally two peaks before and after the anti-resonance frequency f _r as shown in Figure 2.
This system corresponds to the case where only the first voice coil 21 is used in FIG.
For electrical impedance (speaker system) to produce two peaks before and after the anti-resonance frequency f _r, the current to be input is decreased in response to increase in the impedance, efficiency of sound radiated from the speaker is reduced.

Therefore, in order to prevent this reduction in efficiency, an impedance compensating circuit 30A having an impedance Zc for converting the electrical impedance of the speaker system into a constant resistance is inserted in series with the second voice coil 22.

Here, as the impedance compensating circuit 30A, the impedance Zc is determined so that the electric impedance of the speaker system becomes a constant resistance when the passive ejector type cabinet 100 is used. That is, since the electric impedance of the first voice coil 21 is shown in FIG. 2, each element is selected so as to cancel the peak of the characteristic. This impedance compensating circuit 30A is generally represented by FIG. 3, and is expressed by the following equation (1) in mathematical expression.

[0027]

(Equation 7)

In the above equation (1), the resistances r _C1 and r _C2
Is generally smaller than jωL ₂ , 1 / (jωC ₂ ), and 1 / (jωC ₃ ). Therefore, substantially the same effect can be obtained even if the circuit in FIG. 3 is approximately replaced with the circuit in FIG. The circuit of FIG. 4 is represented by the following equation (2) in mathematical expression.

[0029]

(Equation 8)

Here, each element constant of the impedance compensating circuit 30A depends on the dimensions of the passive radiator type cabinet 100 to be used, but the condition for completely making the electrical impedance of the speaker system constant resistance is uniquely determined. Is done.

Passive radiator type cabinet 10
When 0 is used, the resonance angular frequency of the double voice coil speaker unit is “ω ₀ ”, the equivalent mass of the double voice coil speaker unit is “m ₀ ”, and the equivalent mechanical compliance of the double voice coil speaker unit is “C”.
₀ , the electrical sharpness of the double voice coil speaker unit is “Q ₀ ”, and the mechanical sharpness of the double voice coil speaker unit is “Q _m ”, and the second voice coil 22 with respect to the first voice coil 21. The force coefficient ratio is
The compliance of the air according to the volume in the passive radiator type cabinet 100 is “C _b ”, the equivalent mechanical resistance due to the volume in the passive radiator type cabinet 100 is “r _b ”, and the equivalent mass of the passive radiator 40 viewed from the speaker unit 20 is “ m _p ”, the equivalent mechanical compliance of the passive radiator 40 viewed from the speaker unit 20 is“ C _p ”, and the speaker unit 2
"R _p" and equivalent mechanical resistance of the passive radiator 40 as viewed from 0, when the resistance of the first voice coil 21 and "R _V1", the resistance R _V2 of the second voice coil 22, the compensating circuit elements The inductances L ₁ and L ₂ , the capacitances C ₁ and C ₂ ,
C ₃ , resistances r _C1 and r _C2 are obtained from the following equations (3) to (10).

[0032]

(Equation 9)

Where β, γ _b , γ _p , Q _b ,
Q _p is as shown in the following formulas (11) to (15).

[0034]

(Equation 10)

FIG. 5 is a diagram showing calculation results comparing changes in sound pressure level characteristics and changes in electric impedance characteristics depending on the presence or absence of the impedance compensating circuit 30A in the low frequency range. Referring to FIG. 5, the impedance compensation circuit 3
Electrical impedance depending 0A, together are the constant resistance (electrical impedance characteristic curve → thick line in electrical impedance characteristic curve of the thin line), anti-resonance frequency f the sound pressure level characteristics of that sound pressure levels before and after rises (thin line _r Curve →
It can be seen that the sound pressure level characteristic curve of the bold line).

As described above, the speaker system using the double voice coil speaker unit according to the first embodiment has a single double voice coil speaker unit 20 attached to the passive ejector type cabinet 100 and a dedicated voice coil speaker unit 20. An impedance compensating circuit 30A is provided, and the input impedance of the speaker system can be made constant.

Therefore, the input to the speaker system is always supplied at a constant level, which has the effect of improving the sound radiation efficiency near the anti-resonance frequency of the passive radiator type speaker system.

Embodiment 2 Embodiment 2 A speaker system according to Embodiment 2 of the present invention will be described with reference to FIG. FIG. 6 is a diagram showing a configuration of a speaker system according to Embodiment 2 of the present invention.

In FIG. 6, reference numerals 11 and 12 denote signal input terminals to a speaker, reference numeral 20 denotes a double voice coil speaker unit, reference numeral 21 denotes a first voice coil, reference numeral 22 denotes a second voice coil, and reference numeral 23 denotes a voice coil. Bobbin 30B is an impedance compensating circuit for making the electrical impedance of the speaker system constant resistance, 40B
Is a passive radiator, and 200 is a Kelton type cabinet.

Here, the "Kelton type cabinet provided with the passive radiator" means that the rear space of the speaker unit 20 mounted inside is sealed and
A cabinet 200 having a structure in which a space in front of the speaker unit 20 is acoustically coupled to a passive radiator 40 that emits sound to the outside.

Next, the operation will be described. Electrical impedance characteristics of the Kelton type speaker system having a passive La Jay data is passive La J. motor system similar to, 2 before and after the anti-resonance frequency f _r as shown in Figure 2
Yields two mountains.

[0042] Here, the anti-resonance frequency f _r in the Kelton type having a passive La Jay data, that the acoustic resonance frequency determined from the front of the acoustic space and package sheet plastics Jay data 40 of the speaker unit 20 is there.

Therefore, this method is the first in FIG.
And the electric impedance of the speaker unit 20 (speaker system) has two peaks before and after the anti-resonance frequency _fr , so that the input current corresponds to the rise of the impedance. And the efficiency of the sound emitted from the speaker decreases.

Therefore, in order to prevent the sound efficiency from lowering, an impedance compensating circuit 30 B for making the electric impedance of the speaker system a constant resistance is inserted in series with the second voice coil 22.

Here, as the impedance compensating circuit 30B, when the Kelton type cabinet 200 having the passive radiator is used, the impedance Zc is determined so that the electric impedance of the speaker system becomes a constant resistance.

This impedance compensating circuit 30B is generally shown in FIG. 3 similarly to the case of the passive ejector system speaker system, and the mathematical expression of the impedance Zc is the same as the above-mentioned expression (1).

Further, regarding the above equation (1), the resistance r
_C1, r _{C2 is, jωL 2, 1 / (jωC} 2), 1 / (jωC
Generally smaller than ₃ ). Therefore, substantially the same effect can be obtained even if the circuit in FIG. 3 is approximately replaced with the circuit in FIG. That is, the circuit of FIG. 4 is the same as the above equation (2) in mathematical expression.

Here, each element constant of the impedance compensating circuit 30B depends on the Kelton type cabinet 200 used.
Depends on the dimensions of the loudspeaker system, the condition for completely making the electrical impedance of the speaker system constant resistance is uniquely determined.

When the Kelton system cabinet 200 having a passive radiator is used, the resonance angular frequency of the double voice coil speaker unit is “ω ₀ ”, the equivalent mass of the double voice coil speaker unit is “m ₀ ”,
The equivalent mechanical compliance of the double voice coil speaker unit is “C ₀ ”, the electrical sharpness of the double voice coil speaker unit is “Q ₀ ”, and the mechanical sharpness of the double voice coil speaker unit is “Q _m ”. The ratio of the force coefficient of the second voice coil 22 to the first voice coil 21 is “α”, the equivalent mechanical compliance by the rear space of the speaker unit is “C _b ”, and the equivalent mechanical resistance by the air chamber in the rear space of the speaker unit is “C _b ”. "R _b ",
The equivalent mechanical compliance by the speaker unit front air chamber "C _f", the equivalent mechanical resistance due to the speaker unit front air chamber "r _f", the speaker unit 20
"C _p", "m _p", the equivalent mechanical compliance of the passive radiator 40 as viewed from the speaker unit 20 the equivalent mass of the passive radiator 40 as viewed from,
Passive radiator 4 viewed from speaker unit 20
The equivalent mechanical resistance of 0 is “r _p ”, and the first voice coil 21
When the resistance is "R _V1", the resistance R _V2 of the second voice coil 22, the compensating circuit element inductance L _1, L _2,
The capacitances C ₁ , C ₂ , C ₃ and the resistances r _C1 , r _C2 are calculated by the following formula (1)
6) to (23).

[0050]

[Equation 11]

Where β, γ _b , γ _f , γ _p ,
Q _b , Q _f , and Q _p are as shown in the following equations (24) to (30).

[0052]

(Equation 12)

As described above, the speaker system using the double voice coil speaker unit according to the second embodiment is composed of one double voice coil speaker unit mounted on the Kelton type cabinet 200 provided with the passive radiator. 20 and a dedicated impedance compensation circuit 30B, so that the input impedance of the speaker system can be made constant.

Accordingly, the input to the speaker system is always supplied at a constant level, which has the effect of improving the sound radiation efficiency near the anti-resonance frequency of the Kelton type speaker system having the passive radiator.

[0055]

According to the speaker system of the present invention,
As described above, a passive radiator-type cabinet, a dual voice coil speaker unit attached to the cabinet and having first and second voice coils to which an input signal is applied, and a passive radiator attached to the cabinet, An impedance compensating circuit inserted between the input terminal to which the input signal is applied and the second voice coil to make the input impedance a constant resistance, wherein an inductance which is a circuit element of the impedance compensating circuit is provided. L ₁ , L ₂ ,
When the capacitances are C ₁ , C ₂ and C ₃ and the resistances are r _C1 and r _C2 , the impedance Zc of the impedance compensation circuit
Is expressed by Expression (1), the input impedance of the speaker system can be made constant resistance, and the effect of improving the sound radiation efficiency near the anti-resonance frequency can be achieved.

As described above, in the speaker system according to the present invention, the resonance angular frequency of the double voice coil speaker unit is ω ₀ , the equivalent mass of the double voice coil speaker unit is m ₀ , and the double voice coil speaker unit is m ₀ , The equivalent mechanical compliance of the voice coil speaker unit is C ₀ , the electrical sharpness of the double voice coil speaker unit is Q ₀ , the mechanical sharpness of the double voice coil speaker unit is Q _m , the first voice coil the ratio of the force factor of the second voice coil α with respect to the passive radiator system volume by compliance of the air within the cabinet C _b, the passive radiator scheme equivalent mechanical resistance due to the volume of the cabinet r _b, the speaker unit Equivalent mass of the passive radiator viewed from the viewpoint M _p , the equivalent mechanical compliance of the passive radiator as viewed from the speaker unit is C _p , the equivalent mechanical resistance of the passive radiator as viewed from the speaker unit is r _p , the resistance of the first voice coil is R _V1 , When the resistance of the second voice coil is R _V2 , β = m _p / m ₀ and γ _b = C _b / C
_{0, γ p = C p /} C 0, Q b = ω 0 m 0 / r b, Q p = ω 0 m 0 /
The r _p as a condition, the second voice coil resistance R _V2
Further, since the constants of the respective circuit elements of the impedance compensating circuit satisfy the relations of Expressions (3) to (10), the input impedance of the speaker system can be made constant resistance, and the sound radiation near the anti-resonance frequency There is an effect that the efficiency can be improved.

As described above, the speaker system according to the present invention comprises a passive ejector-type cabinet, a double voice coil speaker unit having first and second voice coils attached to the cabinet and to which an input signal is applied. A passive radiator attached to the cabinet, and an impedance compensation circuit inserted between the input terminal to which the input signal is applied and the second voice coil to make the input impedance constant resistance, When the inductances, which are the circuit elements of the impedance compensation circuit, are L ₁ and L ₂ and the capacitances are C ₁ , C ₂ , and C ₃ , the impedance Zc of the impedance compensation circuit is represented by Expression (2). Making the input impedance of the system a constant resistance Bets can be an effect that it is possible to improve the sound radiation efficiency near the anti-resonance frequency.

As described above, the speaker system according to the present invention comprises a Kelton type cabinet, a double voice coil speaker unit having first and second voice coils attached to the cabinet and to which an input signal is applied. A passive radiator attached to the cabinet; and an impedance compensating circuit inserted between the input terminal to which the input signal is applied and the second voice coil to make the input impedance constant. The inductances of the circuit elements of the impedance compensation circuit are L ₁ and L ₂ , the capacitance is C ₁ ,
When C ₂ , C ₃ and resistances are r _C1 and r _C2 , the impedance Zc of the impedance compensating circuit is represented by the equation (1), so that the input impedance of the speaker system can be made constant. This has the effect that the sound radiation efficiency near the anti-resonance frequency can be improved.

As described above, in the speaker system according to the present invention, the resonance angular frequency of the double voice coil speaker unit is ω ₀ , the equivalent mass of the double voice coil speaker unit is m ₀ , and the double voice coil speaker unit is m ₀ , The equivalent mechanical compliance of the voice coil speaker unit is C ₀ , the electrical sharpness of the double voice coil speaker unit is Q ₀ , the mechanical sharpness of the double voice coil speaker unit is Q _m , the first voice coil Α, the equivalent mechanical compliance due to the rear space of the double voice coil speaker unit is C _b , and the equivalent machine due to the air chamber in the rear space of the double voice coil speaker unit. The resistance is r _b , and the front empty space of the double voice coil speaker unit. The equivalent mechanical compliance due to the air chamber is C _f , the equivalent mechanical resistance due to the front air chamber of the double voice coil speaker unit is r _f , the equivalent mass of the passive radiator viewed from the double voice coil speaker unit is m _p , The equivalent mechanical compliance of the passive radiator viewed from the double voice coil speaker unit is C _p , the equivalent mechanical resistance of the passive radiator viewed from the double voice coil speaker unit is r _p , the resistance of the first voice coil the R _V1, the resistance of the second voice coil when the R _{V2 is, β = m p / m 0} , γ b = C b / C 0, γ f = C f / C 0,
_{γ p = C p / C 0} , Q b = ω 0 m 0 / r b, Q f = ω 0 m 0 /
r _f, the _{Q p = ω 0 m 0 /} r p as a condition, a constant of each circuit element of the resistance R _{V 2} and the impedance compensation circuit of the second voice coil (16) to formula (23) Since the relationship is established, the input impedance of the speaker system can be made constant resistance, and the sound radiation efficiency near the anti-resonance frequency can be improved.

As described above, the speaker system according to the present invention includes a Kelton type cabinet, a double voice coil speaker unit having first and second voice coils attached to the cabinet and to which an input signal is applied. A passive radiator attached to the cabinet; and an impedance compensating circuit inserted between the input terminal to which the input signal is applied and the second voice coil to make the input impedance constant. The inductances of the circuit elements of the impedance compensation circuit are L ₁ and L ₂ , the capacitance is C ₁ ,
When C ₂ and C ₃ are set, the impedance Zc of the impedance compensating circuit is expressed by the equation (2), so that the input impedance as a speaker system can be made constant resistance, and sound radiation near the anti-resonance frequency can be achieved. There is an effect that the efficiency can be improved.

Further, in the speaker system according to the present invention, as described above, the impedance compensating circuit is connected to the first series circuit having the inductance L ₁ and the capacitance C ₁ and the first series circuit. , Resistance r
_Since a third series circuit having a resistance r _C2 , a capacitance C ₃ and an inductance L ₂ is connected in parallel to a second series circuit having _C1 and a capacitance C ₂ , the input impedance as a speaker system is provided. Has a constant resistance, and the sound radiation efficiency near the anti-resonance frequency can be improved.

Further, as described above, in the speaker system according to the present invention, the impedance compensation circuit is connected to the first series circuit having the inductance L ₁ and the capacitance C ₁ and the first series circuit. , Capacity C
₃ and a parallel circuit in which a capacitance C ₂ is connected in parallel to a _second series circuit having an inductance L ₂ , so that the input impedance as a speaker system can be made constant resistance, and the impedance near the anti-resonance frequency can be reduced. There is an effect that the sound radiation efficiency can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram showing a configuration of a passive ejector type speaker system according to Embodiment 1 of the present invention.

FIG. 2 is a diagram showing electric impedance characteristics of the passive ejector type speaker system according to Embodiment 1 of the present invention.

FIG. 3 is a diagram showing an impedance compensation circuit of the passive ejector-type speaker system according to Embodiment 1 of the present invention;

FIG. 4 is a diagram showing another impedance compensation circuit of the passive ejector type speaker system according to the first embodiment of the present invention.

FIG. 5 is a diagram comparing changes in sound pressure level characteristics and electric impedance characteristics depending on the presence or absence of a compensation circuit in a low frequency range of the passive ejector type speaker system according to Embodiment 1 of the present invention.

FIG. 6 is a diagram showing a configuration of a Kelton speaker system including a passive radiator according to Embodiment 2 of the present invention;

FIG. 7 is a diagram showing a configuration of a conventional speaker system.

FIG. 8 is a diagram showing electric impedance characteristics of a conventional speaker system.

FIG. 9 is a diagram showing a sound pressure level characteristic of a conventional speaker system.

[Explanation of symbols]

11, 12 signal input terminal, 20 double voice coil speaker unit, 21 first voice coil, 22
2nd voice coil, 23 bobbins, 30A, 30B
Impedance compensation circuit, 40 passive ejector,
100 passive ejector cabinet, 200
Kelton type cabinet with passive radiator.

Claims (8)

[Claims] 1. A passive radiator-type cabinet, a double voice coil speaker unit attached to the cabinet and having first and second voice coils to which an input signal is applied, and a passive radiator attached to the cabinet, An impedance compensating circuit inserted between the input terminal to which the input signal is applied and the second voice coil to make the input impedance a constant resistance, wherein an inductance that is a circuit element of the impedance compensating circuit is provided. When L ₁ , L ₂ , capacitances are C ₁ , C ₂ , C ₃ , and resistances are r _C1 , r _C2 , the impedance Zc of the impedance compensation circuit is represented by the following equation. . (Equation 1) 2. The resonance frequency of the double voice coil speaker unit is ω ₀ , the equivalent mass of the double voice coil speaker unit is m ₀ , the equivalent mechanical compliance of the double voice coil speaker unit is C ₀ , The electrical sharpness of the double voice coil speaker unit is Q ₀ , the mechanical sharpness of the double voice coil speaker unit is Q _m , and the ratio of the force coefficient of the second voice coil to the first voice coil is Q. alpha, the passive radiator system compliance and C _b of air by volume in the cabinet, the equivalent mechanical resistance due to the volume of the passive radiator type cabinet r _b,
The equivalent mass of the passive radiator viewed from the speaker unit is m _p , the equivalent mechanical compliance of the passive radiator viewed from the speaker unit is C _p , the equivalent mechanical resistance of the passive radiator viewed from the speaker unit is r _p , The resistance of the first voice coil is R _V1 , and the resistance of the second voice coil is R _V2
, Β = m _p / m ₀ , γ _b = C _b / C ₀ , γ _p =
_{C p / C 0, Q b} = ω 0 m 0 / r b, Q p = ω 0 m 0 / r p on condition, the circuit elements of the resistor R _V2 and the impedance compensation circuit of the second voice coil The speaker system according to claim 1, wherein the following constants have the following relationship: (Equation 2) 3. A passive radiator-type cabinet, a double voice coil speaker unit mounted on the cabinet and having first and second voice coils to which an input signal is applied, and a passive radiator mounted on the cabinet. An impedance compensating circuit inserted between the input terminal to which the input signal is applied and the second voice coil to make the input impedance a constant resistance, wherein an inductance that is a circuit element of the impedance compensating circuit is provided. When L ₁ , L ₂ and capacitances are C ₁ , C ₂ , C ₃ , the impedance Zc of the impedance compensation circuit is
Is represented by the following formula. (Equation 3) 4. A skeleton cabinet, a double voice coil speaker unit attached to the cabinet and having first and second voice coils to which an input signal is applied, a passive radiator attached to the cabinet, An impedance compensating circuit inserted between the input terminal to which the input signal is applied and the second voice coil to make the impedance a constant resistance, wherein an inductance which is a circuit element of the impedance compensating circuit is L A speaker system wherein the impedance Zc of the impedance compensating circuit is represented by the following equation, where ₁ , L ₂ , capacitances are C ₁ , C ₂ , and C ₃ , and resistances are r _C1 and r _C2 . (Equation 4) 5. The resonance frequency of the double voice coil speaker unit is ω ₀ , the equivalent mass of the double voice coil speaker unit is m ₀ , the equivalent mechanical compliance of the double voice coil speaker unit is C ₀ , The electrical sharpness of the double voice coil speaker unit is Q ₀ , the mechanical sharpness of the double voice coil speaker unit is Q _m , and the ratio of the force coefficient of the second voice coil to the first voice coil is Q. α, the equivalent mechanical compliance due to the rear space of the double voice coil speaker unit is C _b , the equivalent mechanical resistance due to the air chamber in the rear space of the double voice coil speaker unit is r _b , Equivalent mechanical compliance by front air chamber is C
_f , the equivalent mechanical resistance due to the front air chamber of the double voice coil speaker unit is r _f , the equivalent mass of the passive radiator viewed from the double voice coil speaker unit is m _p , The equivalent mechanical compliance of the passive radiator as viewed is C _p , the equivalent mechanical resistance of the passive radiator as viewed from the double voice coil speaker unit is r _p , the resistance of the first voice coil is R _V1 , and the second is When the resistance of the voice coil is R _V2 , β = m
_p / m ₀ , γ _b = C _b / C ₀ , γ _f = C _f / C ₀ , γ _p = C _p / C
_{0, Q b = ω 0 m} 0 / r b, Q f = ω 0 m 0 / r f, Q p = ω 0 m 0
/ R _p, subject to the resistance R of the second voice coil
5. The speaker system according to claim 4, wherein _V2 and a constant of each circuit element of the impedance compensation circuit have the following relationship. (Equation 5) 6. A skeleton cabinet, a double voice coil speaker unit attached to the cabinet and having first and second voice coils to which input signals are applied, a passive radiator attached to the cabinet, An impedance compensating circuit inserted between the input terminal to which the input signal is applied and the second voice coil to make the impedance a constant resistance, wherein an inductance which is a circuit element of the impedance compensating circuit is L ₁ , L ₂ and capacitances C ₁ , C ₂ , C ₃ , the impedance Zc of the impedance compensation circuit
Is represented by the following formula. (Equation 6) 7. The impedance compensating circuit is connected to a first series circuit having an inductance L ₁ and a capacitor C _{1 and} a second series circuit having a resistor r _C1 and a capacitor C ₂ . 5. The speaker system according to claim 1, wherein the circuit comprises a parallel circuit in which a third series circuit of a resistance r _C2 , a capacitance C _3, and an inductance L ₂ is connected in parallel. 8. The impedance compensating circuit is connected to a first series circuit having an inductance L ₁ and a capacitor C _{1 and} a second series circuit having a capacitor C ₃ and an inductance L ₂ . speaker system according to claim 3 or 6, wherein the capacitance C ₂ is composed of a parallel-connected parallel circuit to circuit.