JP2001186591A - Loudspeaker system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain a loudspeaker system that can be combined with loudspeakers having various impedance values. SOLUTION: The loudspeaker system 10 includes a piezoelectric vibrator 12 which acts as a sounder. An impedance conversion transformer 14 is connected to the piezoelectric vibrator 12. A 1st external connection terminal 18 is connected to one input terminal 14a of the impedance conversion transformer 14 via a 1st receiver 16, and a 2nd external connection terminal 22 is connected to the input terminal 14a via a 2nd resistor 20. A 3rd external connection terminal 24 is connected directly to other input terminal 14b of the impedance conversion transformer 14.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a speaker system, and more particularly, to a speaker system used in combination with another speaker, for example.

[0002]

2. Description of the Related Art As a loudspeaker, there is, for example, a dynamic loudspeaker. The dynamic loudspeaker has a stable impedance except for a resonance frequency. Such speakers include those for bass, medium, and treble, and by combining these speakers,
A wide range can be reproduced. When a plurality of dynamic speakers are combined, a network and an attenuator are separately provided outside in order to adjust the cutoff frequency and efficiency of each speaker. Recently, a speaker system including a network and an attenuator has been commercialized, and a combination of a plurality of speakers has become easy.

[0003]

The speaker has 4Ω,
Some have impedances such as 6Ω and 8Ω,
Efficiency is reduced when speakers having different impedances are combined, and it is necessary to combine speakers having the same impedance. However, since networks and attenuators are configured assuming a specific impedance, even if these circuits are used,
Speakers with different impedances cannot be combined. Further, if impedance is adjusted by connecting a resistor or the like to the dynamic speaker, loss occurs in the resistor portion, and the predetermined performance cannot be exhibited.

[0004] Therefore, a main object of the present invention is to provide a speaker system which can be combined with speakers having various impedances.

[0005]

SUMMARY OF THE INVENTION The present invention provides a speaker including a piezoelectric vibrator and a transformer or inductance for impedance conversion or boosting, and having two input terminals for inputting signals to the transformer or inductance. A first external connection terminal connected to one of the input terminals via a first resistor; a second external connection terminal connected to one of the input terminals via a second resistor; A third external connection terminal connected to the other of the terminals is provided.

In a piezoelectric speaker using a piezoelectric vibrator, since the input impedance is high, impedance conversion is performed using a transformer or an inductance to match with an external circuit. At this time, 4Ω, 6
An adjusting resistor is connected to an input terminal of a transformer or an inductance so as to have an impedance of Ω, 8Ω, or the like. At this time, by connecting two resistors to one input terminal and inputting a signal via any one of the resistors, the speaker system can be used as a speaker system having two kinds of impedances. Further, by short-circuiting the external connection terminal connected to the two resistors, a signal is input to a transformer or an inductance in a state where the two resistors are connected in parallel. Therefore, it can be used as a speaker system having three kinds of impedances depending on how to use the external connection terminal. Since the input impedance of the piezoelectric vibrator is high, a transformer, an inductance, a resistance, and the like are used for impedance adjustment, and almost no current flows when an input signal is applied.

The above and other objects, features and advantages of the present invention will become more apparent from the following detailed description of embodiments with reference to the drawings.

[0008]

FIG. 1 is an illustrative view showing one example of a speaker system of the present invention. Speaker system 10
Includes a piezoelectric vibrator 12 serving as a sounding body. Piezoelectric vibrator 1
Since 2 has a high input impedance, a transformer or an inductance is connected for matching with an external circuit, for example, for impedance conversion or boosting.
Here, an impedance conversion transformer 14 is connected to the piezoelectric vibrator 12. At this time, for example, the minimum impedance in the reproduction band viewed from the input terminal side is 1.2Ω.
Is set to be

A first external connection terminal 18 is connected to one input terminal 14 a of the impedance conversion transformer 14 via a first resistor 16. In this case, a resistor having a resistance value of 6.8Ω is used as the first resistor 16. Further, a second input terminal 14 a of the impedance conversion transformer 14 is connected to a second input terminal 14 a via a second resistor 20.
Are connected. In this case, a resistor having a resistance value of 4.7Ω is used as the second resistor 20. Further, a third external connection terminal 24 is directly connected to the other input terminal 14b of the impedance conversion transformer 14. Therefore, this speaker system 10
Is a speaker system having three external connection terminals.

The speaker system 10 can be used in combination with another speaker. For example, 8
When combined with a speaker having an input impedance of Ω, the first external connection terminal 18 and the third external connection terminal 24 are used for signal input. In this case, the input impedance Z viewed from the external connection terminals 18 and 24
Is the input terminal 14 of the impedance conversion transformer 14.
a, 14b, the input impedance and the first resistance 1
6 and Z = 1.2 + 6.8 = 8
(Ω).

When combined with a speaker having an input impedance of 6Ω, the second external connection terminal 22
And the third external connection terminal 24 are used for signal input. In this case, the input impedance Z viewed from the external connection terminals 22 and 24 is the impedance conversion transformer 1
4 is the sum of the input impedance seen from the input terminals 14a and 14b and the resistance of the second resistor 20, Z = 1.2
+ 4.7 ≒ 6 (Ω).

Further, when combined with a speaker having an input impedance of 4Ω, the first external connection terminal 1
8 and the second external connection terminal 22 are short-circuited, and these external connection terminals and the third external connection terminal 24 are used for signal input. In this case, the first resistor 16 and the second resistor 20 are connected in parallel and connected to the impedance conversion transformer 14. Therefore, the input impedance Z seen from the external connection terminals 18, 22, 24
Is Z = 6.8 × 4.7 / (6.8 + 4.7) +1.2
= 2.78 + 1.2 ≒ 4 (Ω).

FIG. 2 shows the relationship between the frequency and the sound pressure level when the input impedance of the speaker system 10 is switched. As can be seen from FIG. 2, when the input impedance is 8Ω, the sound pressure level is the lowest, and when the input impedance is 4Ω, the sound pressure level is the highest. in this way,
By switching the input impedance, the efficiency of the speaker system 10 can be switched.

As described above, the speaker system 10 can be used as a speaker system having three input impedances. Therefore, depending on how the external connection terminals 16, 22, 24 are connected, 4Ω,
It can be used in combination with any of the other speakers having impedances of 6Ω and 8Ω. Therefore, it is not necessary to separately manufacture a speaker system having a plurality of input impedances in order to combine with another speaker.

[0015]

According to the present invention, a speaker system having three types of input impedances can be used according to a method of connecting three external connection terminals. Therefore, it is not necessary to manufacture a speaker system having a plurality of input impedances in order to combine with speakers having various input impedances, and a single speaker system can be used.

[Brief description of the drawings]

FIG. 1 is an illustrative view showing one example of a speaker system of the present invention;

FIG. 2 is a graph showing a relationship between a frequency and a sound pressure level when the input impedance of the speaker system shown in FIG. 1 is switched to 4Ω, 6Ω, and 8Ω.

[Explanation of symbols]

Reference Signs List 10 speaker system 12 piezoelectric vibrator 14 impedance conversion transformer 14a, 14b input terminal of impedance conversion transformer 16 first resistor 18 first external connection terminal 20 second resistance 22 second external connection terminal 24 third external connection Terminal

Claims (1)

[Claims] 1. A speaker system including a piezoelectric vibrator and a transformer or an inductance for impedance conversion or boosting, and having two input terminals for inputting a signal to the transformer or the inductance, wherein the input terminal A first external connection terminal connected to one of the input terminals via a first resistor, a second external connection terminal connected to one of the input terminals via a second resistor, and the other of the input terminals. A speaker system, wherein a third external connection terminal to be connected is provided.