JP2005110192A - Electric conductor for speaker control - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To configure a small and simple speaker system capable of improving low-pitched sound reproduction limit, using a full-range speaker, a closed cabinet, and a filter circuit including an electric conductor, without degradation in overall characteristics of the speaker, by performing speaker control with electrical characteristics, such as a minimum resonance frequency, electromotive force, and resistance change of the electric conductor connected in series or parallel to the speaker. <P>SOLUTION: Although the type of a dynamo-electric speaker is used as the structure of the electric conductor, a vibration plate is made unnecessary as the purpose of emitting sound. The electric conductor is formed with a moving-coil 1 for the purpose of electrical characteristics, a lead line 2, a bobbin 3, a holding parts 4 for a vibration system such as a mass regulating material 5, parts for forming a magnetic circuit such as a pole piece 8, a yoke 6, a plate 9, and a magnet 7, as well as a frame 10 for holding the whole, and a terminal 11. The minimum resonance frequency and impedance characteristics can be changed by joining the equivalent mass regulating material 5 to the bobbin wound around the moving-coil of the electric conductor. The target impedance property can be also approached by increase/decrease in resiliency or movement resistance of the moving-coil holding parts of the electric conductor. An electric conductor having a minimum resonance frequency lower than the speaker is connected to the speaker in parallel. Or, an electric conductor using electrical characteristics below a minimum resonance frequency is connected to the speaker in series, by suitably establishing the minimum resonance frequency according to low-pass property of the speaker. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention is an electrodynamic body for the purpose of speaker control, and particularly for the purpose of reducing distortion in a low frequency range, and by incorporating the electrodynamic body as a passive element forming a filter circuit in a speaker system, the electrodynamic body The present invention relates to a vibration control technique for speakers based on electrical characteristics generated between terminals.

  In the characteristics of the speaker system, nonlinear distortion increases below the minimum resonance frequency, so it is necessary to set the minimum resonance frequency as low as possible. In this method, particularly in the downsizing of the speaker system, the acoustic conversion efficiency and the high frequency characteristics deteriorate. Even so, the speaker diaphragm had to be heavy.

  As a result, there is a need for a composite speaker system dedicated to bass and treble speakers, and the filter circuit based on passive elements of the speaker system is mainly intended for composite speaker systems, and is filtered by coils, capacitors, resistors, etc. A circuit is formed to control output sound pressure frequency characteristics.

  Low-frequency sound reproduction by a small speaker system reduces the low-frequency radiation efficiency due to the small diaphragm area of the speaker, requires a large amount of amplitude, and inevitably increases nonlinear distortion.

  Non-linear distortion occurs frequently below the lowest resonance frequency of the speaker system, and is influenced by the elasticity of the damper and the edge, which are the holding parts of the movable coil and diaphragm, and by the aeroelasticity in the closed cabinet.

  As an element for increasing the bass reproduction limit, it is necessary to soften such elasticity and lower the minimum resonance frequency. However, it is inevitable that the minimum resonance frequency is increased when the speaker system is miniaturized.

  Although it is possible to lower the minimum resonance frequency by making the diaphragm of the speaker heavier, it is difficult to improve the overall sound quality by deteriorating the electroacoustic conversion efficiency, transient characteristics, high frequency characteristics, etc.

  In addition, it is not easy to improve the overall sound quality due to the low-frequency acoustic characteristics including the diffraction effect peculiar to the open back cabinet and the restrictions on the structure and shape.

  The present invention is applicable to a small sealed cabinet that does not have a problem of acoustic characteristics due to the diffraction effect, in addition to the great difficulty in reproducing bass.

  Even if the minimum resonance frequency of the speaker is not set too low, the main issue is to easily enhance the bass reproduction capability of a small sealed speaker system that is greatly influenced by aeroelasticity.

  In the present invention, speaker control is performed based on electrical characteristics such as the minimum resonance frequency, electromotive force, and resistance change of the moving coil in the electrodynamic body connected to the speaker input terminal.

  The structure of the electrodynamic body uses the type of electrodynamic speaker, but does not require a diaphragm for producing sound, and the movable coil 1, lead wire 2, bobbin 3, and mass adjusting material 5 for the purpose of electrical characteristics. And the like, and a pole piece 8 forming a magnetic circuit, a yoke 6, a plate 9, a magnet 7, and a frame 10 and a terminal 11 for holding the whole.

  The equivalent mass adjusting material 5 is joined to the bobbin around which the movable coil of the electrodynamic body is wound, and the minimum resonance frequency and impedance characteristics are changed.

  The target impedance characteristics are also brought close by the elasticity of the moving coil holding part of the electrodynamic body and the increase and decrease of the movement resistance.

  An electrodynamic body having a minimum resonance frequency lower than that of the speaker is connected in parallel with the speaker.

  Alternatively, the lowest resonance frequency is appropriately set according to the low frequency characteristics of the speaker, and an electrodynamic body that also uses electrical characteristics below the lowest resonance frequency is connected in series with the speaker.

  In particular, in improving the sound quality of a small and simple speaker system, it is difficult to achieve both low frequency characteristics and electroacoustic conversion efficiency, transient characteristics, high frequency characteristics, etc. By connecting an electrodynamic body, it is possible to increase the bass reproduction limit without impairing the characteristics of the speaker.

  Parallel type electrodynamic body enables generation of electromotive force with little non-linear distortion, and by simply connecting in parallel to the speaker, the lowest resonance frequency and electromotive force of both are synthesized without disturbing the characteristics of the speaker. The minimum resonance frequency can be lowered, and nonlinear distortion can be reduced from low to high.

  The series type electrodynamic body enables an effect of canceling the non-linear distortion caused by the elastic load of the speaker due to the current change in the low-range elastic load.

  In addition, since a gentle high-frequency attenuation characteristic is required, the frequency characteristic can be improved with a simple filter circuit.

  Since an electrodynamic body can be handled as a kind of passive component that can control a speaker by using electrical characteristics, there is no restriction on a speaker system and a speaker system system, and the application range is wide.

  As shown in FIG. 2, a speaker system is formed by a small sealed cabinet 12, a full range speaker 13, a filter circuit board 14, an electrodynamic body 15, and the like.

  The electrodynamic body and the filter element may be installed outside the cabinet by forming a filter circuit on the same substrate.

  The magnetic circuit of the electrodynamic body preferably has a strong form so that an electromotive force can be easily obtained, and the rated impedance is preferably as low as possible.

  It is preferable that the rated input of the electrodynamic body can withstand the rated input of the speaker.

  Embodiment 1 of the parallel type electrodynamic body in FIG. 2 will be described with reference to FIGS. 1, 3, and 4.

  In FIG. 1, the mass-increasing material 5 of the bobbin 3 extending from the moving coil is made high-compliant by making the holding part 4 soft and ensuring air permeability so as to suppress air resistance so that the moving coil 1 moves efficiently. Thus, the lowest resonance frequency of the electrodynamic body is lowered, and the electrodynamic bodies are connected in parallel as shown in the circuit diagram of FIG.

  In the characteristic shown in FIG. 4, the peak r2 indicating the lowest resonance frequency of the impedance characteristic and the frequency characteristic f1 indicate the characteristic of the speaker system in which the electrodynamic body and the filter circuit are connected as shown in the circuit diagram of FIG. The impedance characteristic r3 and the frequency characteristic f2 indicate the characteristics of the speaker system in which the electrodynamic body and the filter circuit are not connected.

  The peak r1 of the lowest resonance frequency is an impedance characteristic of only the parallel type electrodynamic body, and the lowest resonance synthesized with the peak r3 of the lowest resonance frequency not connected by connecting in parallel with the speaker as shown in the circuit diagram of FIG. A frequency peak r2 is obtained, and a frequency characteristic f1 that can suppress a high-frequency rise by the filter circuit is obtained.

  A second embodiment of the series-type electrodynamic member in FIG. 2 will be described with reference to FIGS. 1, 5, and 6.

  By obtaining low compliance that makes the holding component 4 in FIG. 1 stiff to some extent, the electrical characteristics of the movable coil 1 having a large elastic load are obtained, and a viscous material is used together with the holding component 4 to suppress an increase in the resistance value of the lowest resonance frequency. .

  In the characteristics shown in FIG. 6, the impedance characteristic r5 and the frequency characteristic f3 indicate the characteristics of the speaker system that connects the electrodynamic body and the filter circuit as shown in the circuit diagram of FIG. f4 indicates the characteristics of the speaker system in which the electrodynamic body and the filter circuit are not connected.

  The peak r4 of the lowest resonance frequency is an impedance characteristic of only the series type electrodynamic body, and the peak r4 is suppressed by the viscous resistance of the holding component 4, but the current decreases in that portion.

  For this reason, since a dip occurs in the frequency characteristics of the speakers connected in series with an electrodynamic body, an impedance characteristic peak r4 is set in the low frequency peak portion p of the speaker frequency characteristics to help flatten the frequency characteristics.

  Cross section of electrodynamic body   Speaker system sectional view showing an embodiment of an electrodynamic body   Circuit diagram of Example 1   Characteristic diagram for explaining Example 1   Circuit diagram of Example 2   Characteristic diagram for explaining Example 2

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Movable coil 4 Holding parts 5 Mass adjustment material 12 Sealed cabinet 13 Speaker 14 Filter circuit board

Claims (2)

  Using a speaker structure with no diaphragm for acoustic output, moving coils, lead wires, bobbins, mass adjustment materials, holding parts for these vibration systems, magnetic circuit parts, frames, terminals, etc. A speaker control electromotive body formed of   The loudspeaker control electrodynamic body according to claim 1, wherein the electrodynamic body is connected to the speaker in parallel or in series to use the electrical characteristics of the electrodynamic body for speaker vibration control.

Images