JPS61242196A - Speaker - Google Patents

Abstract

PURPOSE:To regenerate all bands with one diaphragm and to obtain flat sound pressure frequency characteristic and good acoustic image static and transient characteristics by winding or connecting several voice coils or a voice coil composed of multiple layers to the concatenation part of the diaphragm. CONSTITUTION:Assuming that the grade is 6dB, to raise the sound pressure level at low-pitched tone side L 6dB, if the electric impedance Zs=8OMEGA at the speaker terminal, the electric impedance of a voice coil 14 for regeneration at high-pitched tone side H is 8OMEGA and that of voice coils 12 and 13 are 16OMEGA with the coil length (l) for the low-pitched tone side L regeneration and twice the length of the voice coil 14. When current (i) of a signal is applied to the speaker terminal, the voice coil 14 produces driving force Bli. On the other hand, current of 1/2 is flowed in the voice coils 12 and 13, so that their composite driving force will be F=2X(BX2lXi/2)=2Bli, causing the driving force at the low-pitched tone side L to be larger for 6dB.

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention is directed to a vibrator unit in which a voice coil is wound or joined to each connected portion of a vibrator portion in which vibrators formed in approximately semi-cylindrical shapes are connected in parallel. The present invention relates to a speaker having a diaphragm, and relates to the configuration and structure forming a voice coil and the connection of a divided network attached thereto.

[Background of the invention]

As a speaker with multiple voice coils,
As described in Japanese Patent No. 5-25265, there is a configuration shown in FIG. 2 in which a plurality of voice coils are wound around one bobbin. In addition, as a conventional thin speaker, a speaker with the cross-sectional structure shown in Figure 3 (commonly called the Niblathara type)
There is. Although these speakers have advantages, they also have many disadvantages.

The reasons for achieving the present invention and the advantages of the present invention will be described below.

[Conventional Example 1]; As a speaker with multiple voice coils, the 5KS as described in 'I Kaisho 55-25265
There is a configuration shown in FIG. 2 in which a plurality of voice coils are wound around one bobbin. This speaker 1 reproduces the entire band (
A voice coil 2 that is driven by a voice coil 2 and a low-pass filter 3 form a voice coil 4 that reproduces frequencies below 200 Hz. As shown in Fig. 4, the sound pressure frequency characteristics are reproduced by the voice coil 2 as a characteristic A, voice coil 4 as a characteristic mouth, and synthesized by the two voice coils 2.4 as a composite characteristic C. at 200 Hz
The following characteristics are the emphasized characteristics.

Further, the electrical impedance characteristic of this speaker is as shown in characteristic 2. The reason for this is that in the band below 200 Hz, the voice coils 2.4 are driven in parallel, so the electrical impedance Zs is lower than the predetermined electrical impedance Zs (for example, 8Ω). Furthermore, since the voice coil is wound, inductance is generated, and the electrical impedance Zss increases as the frequency range becomes higher, resulting in a busy and undulating electrical impedance characteristic as shown in characteristic 2. This has the disadvantage that the operation of the power amplifier that drives the speaker tends to become unstable.

[Conventional Example 2]; In recent years, heat-resistant synthetic resin sheets (hereinafter simply referred to as plastic sheets) have become available, and as shown in FIG. The resulting diaphragm 5 is heated and press-molded, and a voice coil is wound or bonded around each connecting portion 5b of the vibrator group to form a vibration system.A full-band speaker with a cross-sectional groove channel as shown in FIG. 3 is manufactured. It started to be done.

The advantage of this speaker is that the mass of the vibration system is light, so it has better transient characteristics than the conventional two-type full-band type.
Moreover, in terms of form, it can be constructed into an extremely thin speaker unit.

On the other hand, since the mass of the vibration system has become lighter, there is a drawback that the sound pressure frequency characteristic is not flat, but increases (steps occur) as the frequency becomes higher, as shown in FIG.

This is because, as shown in FIG. 7, the radiation impedance Zr characteristic Xr of the speaker changes depending on the frequency.

The radiation impedance Zr is Zr = Rr + JXr. Here, Rr is called radiation resistance and Xr is called radiation reactance, and approximately Rr fa2Zo lc"a" = dish"w22
2C 8ka 8Z.

Ka Zo −= −aw 3π 3C in Xr. Here, Zo 11 characteristic impedance (Zo
=ρoC) ρ0: Density of air C: Speed of sound λ: Wavelength a: Radius of diaphragm w: 2πf f Two frequencies However, most of the speakers shown in Figures 3 and 5 are rectangular, but they will be explained here. is described as a piston disk for simplicity.

be. This mass calmness is the mass added to one side of the diaphragm and is called the added mass of air, and is twice this value for a speaker in an infinite baffle. However, this relationship is k a (1
This is almost true in the low band of ka)1, but in the high band of ka)1, Xr gradually decreases as shown in Figure 7, so it can be seen that the demon also decreases.On the other hand, in the mass control region Cf>f, ) The output sound pressure level (SPL) in the band ka(l) is determined by the following equation.

Here, C: Constant B: Magnetic flux density t: Voice coil length a: Effective radius of the vibration system MO = Effective mass of the vibration system, Mo = Md + MvJuan Zs: Electric impedance of the voice coil. The effective quality tMo is the mass Md of the diaphragm of the vibration system,
The mass of the voice coil Mv N consists of the additional quality of air tMa. As can be seen from Fig. 7, at frequencies ka>1, the additional mass Ma of air gradually decreases as described above, so the sound pressure frequency characteristics change as shown in Fig. 6 with a step (h = 6d
B) occurs, resulting in unfavorable sound quality. The dimensions of the diaphragm of a speaker with this characteristic are 13 am x 13 a
m square, additional mass of air 2 Ma = 2.6 g
, mass of diaphragm 1.4g, mass of voice coil 1.2
It was g.

However, since the additional mass of air is proportional to the cube of the effective radius a of the diaphragm, this step increases as the diaphragm becomes larger.

[Purpose of the invention]

In view of the above circumstances, it is an object of the present invention to provide a speaker that reproduces the entire frequency range with a single diaphragm, has flat sound pressure frequency characteristics, good sound localization, and has excellent transient characteristics. .

[Summary of the invention]

A voice coil consisting of a plurality of layers or multiple layers is wound or bonded to the connecting portion 5b of the diaphragm 5. Then, the voice that drives each band increases the sound pressure level on the bass side, as shown by the dotted line E in Fig. 6, or decreases the sound pressure level on the treble side, as shown by the chain line. A dividing network is connected to the coil, and the driving force is weighted to perform multiple driving to flatten the sound pressure frequency characteristics.

[Embodiments of the invention]

Examples will be described below using figures.

[Embodiment 1] This embodiment is a means for increasing the level of bass sound where the sound pressure level is low. An example of the structure of the speaker in this case is already shown in FIG. Here, 5a is a diaphragm, 5a is a vibrator, 5b is a joint, and b is a plurality or multilayer voice coil, which is wound around or joined to the joint. 7 is a plurality of magnetized magnets, 8.9 is a yoke plate, 10 is a damper, and 11 is a frame.

FIG. 1 is a wiring diagram of a plurality of (multilayer) voice coils and an accompanying divided network.

Here, 12, 13, and 14 are voice coils, and 15 is a low pass filter (LPF) 16 and a bypass filter (HP
F) Division network (DNW) consisting of 17, 18 is an attenuator (ATT). Here, to make it easier to explain the invention in detail, assuming that the above-mentioned level difference is 6 dB, in order to increase the sound pressure level (SPL) on the bass side by 6 dB, the electric power as seen from the speaker terminal is impedance z
Assuming that 8=80, in FIG. 1, the voice coil 14 for high-pitched H reproduction is 8Ω,
are for bass reproduction, and the wire length t is twice that of the voice coil 14, and the electrical impedance is 16Ω.
At that time, the configuration of voice coil 12, 13, 14 is the 8th
You can do it as shown in the figure. If a current signal of i is applied to the terminal of the speaker, a driving force Bti is generated in the voice coil 14. On the other hand, since a current of i/2 flows through each of the voice coils 12 and 13, the combined driving force of the two coils F = 2x (Bx 2tX i/2) = 2Bt
i, and the driving force on the bass side is 6 dB higher. As a result, as shown in FIG. 9, the sound pressure frequency characteristic of the bass side passing through the low pass filter 16 is
If the signal is not passed through the filter 17, the characteristic H is indicated by the dotted line) 0) Furthermore, the sound pressure frequency characteristic of the high-pitched sound side H which is passed through the bypass filter 17 is as shown by the dotted line. When the characteristics are combined, the sound pressure frequency time d is flat over the entire band. Similarly, the electrical impedance Zs seen from the input terminal of the speaker will not drop below the predetermined impedance.0 If the step difference is 6 dB or more, either increase the number of voice coils on the bass side one by one or use an attenuator. The sound pressure level (SPL) on the treble side H may be lowered in step 18.

Also, if the level difference is 6 dB or less, voice coil 1
The electrical impedance of 2.13 was set to 16 Ω, and the wire length of the voice coil was shortened (the cross-sectional area of the conductive film was made smaller to match the electrical impedance) to match the sound pressure level (SPL) of the high-pitched sound side H. That's fine.

If the electrical impedance seen from the speaker terminal is other than 80, the voice coil may be changed accordingly. Moreover, the division frequency f of the division network 150 is ka=1~
It is sufficient to select a frequency between 30 and 30.

In Conventional Example 1, the sound pressure level can only be increased in a limited band of 200 Hz or less, and the electrical impedance is further reduced, but in the present invention, the sound pressure level can be increased flatly over a wide band. As a result, a flat sound pressure frequency characteristic is obtained over the entire band, and the electrical impedance z8 does not drop significantly below the predetermined value (8Ω).

[Example 2]; In this example, the treble side H where the sound pressure level is high is
It is a means to reduce the level of FIG. 10 is a wiring diagram of a plurality of voice coils (multiple layers) and a divisional network associated therewith. Here, 19.20 is the voice coil,
21 is a divided network (D) consisting of a low pass filter (LPF) 22 and a bypass filter (HPF) 23.
NW), 24 is an attenuator (ATT), and 25 is a resistor (R) for making the total electric impedance Zs=8 with the voice coil 19.

Here, to make it easier to explain the present invention in detail, assuming that the above-mentioned level difference is 6 dB, in order to lower the sound pressure level (SPL) on the treble side H by 6 dB, it is necessary to Assuming that the electrical impedance Zts = 80, the voice coils 19 and 20 are connected in series with the same wire length t. At that time, voice coil 19.2
0 may be configured as shown in FIG. Further, the electrical impedance is each 4Ω, and the resistor 25 is 4Ω. Since the bass-side signal flows to both the voice coils 19 and 200, the driving force is F=BX2tXi=2Bti. On the other hand, since the high-pitched sound side H flows only to the voice coil 19, the driving force F=Bti, and the driving force F of the high-pitched sound side H is 6d.
B will decrease. As a result, as shown in FIG. 12, the bass side that passes through the low-pass filter 22 has a sound pressure frequency characteristic (if it does not pass through the filter 22, it has the characteristic shown by the dotted line). Further, the high-pitched sound side H that passes through the bypass filter 23 has a sound pressure frequency characteristic Wa (if it does not pass through the filter 23, it has the characteristic power shown by the dotted line). When the characteristics are combined, a flat sound pressure frequency characteristic is obtained over the entire band.Since the electrical impedance of the voice coil 19 is 4Ω, the sum with the resistor 25 is set to 80Ω, so that the sound pressure frequency characteristic is flat when viewed from the input terminal of the speaker. Electrical impedance Za
does not drop significantly below the predetermined value (8Ω). If the step in the sound pressure frequency characteristic of a full-band speaker constructed by simply connecting the voice coils 19 and 20 in series and having an electrical impedance Zs = 80 is 6 dB, then the difference in the sound pressure frequency characteristic is 6 dB. A flat sound pressure frequency characteristic can be obtained throughout.

If the level difference is 6 dB or more, increase the length of the voice coil 20 (>4 Ω), shorten the length of the voice coil 19 (>4 Ω), and adjust the resistor 25 so that the combined impedance becomes 80. Possible methods include increasing the resistance value (R>40) and lowering the level on the high frequency side using an attenuator (ATT) 24.

Next, if the level difference is 6 dB or less, conversely to the above, shorten the length of voice coil 20 (< 4 Ω) and increase the length of voice coil 19 (> 4 Ω) to increase the combined impedance to 80 dB.
The resistance value of the resistor 25 is made small (R<40
) O As described above, according to the present invention, a flat sound pressure frequency characteristic can be obtained, and the electrical impedance Za does not significantly decrease below the predetermined value (8Ω). [Effects of the Invention] From the above, As is clear, according to the present invention, it is possible to reproduce flat sound pressure frequencies in the entire band with a single diaphragm, and a speaker with good sound image localization and good transient characteristics can be obtained. Furthermore, since the electrical impedance characteristic does not drop significantly below a predetermined value (for example, 8Ω), it has the effect of stabilizing the operation of the power amplifier that drives the speaker.

The technology of the present invention can be applied to other types of electrodynamic speakers, for example.

[Brief explanation of drawings]

FIG. 1 shows the voice coil of a speaker according to Embodiment 1 of the present invention.
A wiring diagram showing the configuration of a split network, etc., Fig. 2 is a wiring diagram of a conventional speaker with two voice coils, Fig. 3 is a cross-sectional structure diagram of the conventional and present speakers, and Fig. 4 is a diagram of the conventional speaker with two voice coils. Figure 5 is a perspective view of the diaphragm used in the speaker shown in Figure 3, Figure 6 is a sound pressure frequency characteristic diagram of a conventional speaker, and Figure 7 is the radiation impedance of the piston disk. Characteristics diagram, FIG. 8 is a configuration diagram showing how to wind the voice coil of the present invention, FIG. 9 is a schematic diagram of sound pressure frequency characteristics showing the main purpose of the present invention, and FIG. 10 is a second embodiment of the present invention. FIG. 11 is a configuration diagram showing how to wind the voice coil, and FIG. 12 is a schematic diagram of sound pressure frequency characteristics. Mutual: diaphragm, 6: voice coil consisting of multiple (multiple layers), 7:...
・Column magnet, 8.9... Yaw 1 plate, 10... Damper, 11...
...Frame, 12.13.14.19.20.
......Multiple voice coils, 15.21...
......Divided network, 16.22...
...Low pass filter, 17.23...
...Bypass filter, 18.24...
・Attenuator, 25......Resistor. 'X+ side 6771g $7-shame fii @ 箪V=country! Jb Name 4 Circulation liquid number - '1.7 Figure ktz l 8 times cl To the imperial beak is ro Note ATT2+ Fu ]t Figure (α) (g) [Mon '5 12 mouth d Procedural amendment (spontaneous) Case Indication of Patent Application No. 82A65 of 1985 Name of the invention Person who makes speaker correction Fin and accountant Name of patent applicant (5101 Manufactured by Hitachi Co., Ltd. Column.Drawings.Amendment t The statement "Radiation impedance 2 has...a mountain..." from page 4, line 15 to page 5, line 18 of the specification is corrected as follows. [Radiation impedance zr is Zr = Rr -4-, rxr.Here, %Rr is radiation resistance and xr is called radiation reactance, which is approximately 2 2C. 3r 5C.Here, zO: characteristic impedance (Zo = ρ
oC) ρ0: Density of air C: Speed of sound λ: Wavelength a: Radius of diaphragm ω: 2 rf f 2 frequencies However, most of the speakers shown in Figures 3 and 5 are rectangular, but they will be explained here. For simplicity, we describe it as a bis)7 disk, and Ma is one mass that is independent of frequency.'' 2 Specification *Saa, line 12, 17) Correct rbJ to ``6''. 5. "Conductive film" on page 10, line 1418 of the specification is corrected to "conductor." 4. Correct "8" in line 3 of specification 12jj to "8Ω". 5. Figure g1, Figure 3, and Figure 4 are corrected as shown in the attached sheet. Hanawa 1 [! 1

Claims (1)

[Claims] In a planar drive type speaker having a diaphragm in which a voice coil is wound or joined to each connecting part of a group of vibrators in which vibrators formed in a substantially semi-cylindrical shape are connected in parallel, the voice coil is arranged in plurality. The voice coils are wound in series or in parallel, and the voice coils are divided into frequency bands, each band division network is connected, and the driving force is weighted to perform multiple driving to achieve flat sound pressure frequency characteristics. A speaker characterized by obtaining.