JPS581030Y2 - Coaxial speaker system - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a coaxial speaker system with flat sound pressure characteristics and flat phase characteristics.

FIG. 1 shows a conventional example.

This shows a 3-way speaker system in which a woofer, squawker, and tweeter are arranged flat on one buckle surface.

This kind of speaker system uses woofer 2 for the bass range,
The squawker 3 reproduces the midrange frequency range, and the tweeter 4 reproduces the high frequency range.

When this system attempts to reproduce complex sounds such as the human voice, each frequency band is played separately.

In other words, the same sound will be played from different locations.

The solution to this problem is the composite coaxial speaker system.

Conventional examples include those shown in FIGS. 2 and 3, for example.

In the figure, 5 is a magnetic circuit plate 6 magnet, 7
is the magnetic circuit plate, 8 is the frame, 9 is the gasket, 10 is the cone diaphragm, 11 is the dust blues, 12 is the voice coil, 13 is the damper, 14 is the support, 15
indicates a dome diaphragm.

In FIG. 2, cone paper is used for the woofer diaphragm 10, and a dome diaphragm 15 is used as the tweeter, which is placed in front of the woofer diaphragm.

Similarly, in FIG. 3, paper cone is used as the diaphragm 10 of the woofer, and a horn-shaped tweeter horn 16 is used as the tweeter.

In the case shown in Figure 2, the tweeter section is suspended in the air and there is little baffling effect on the sound emitted from the tweeter section, and the sound waves emitted from the woofer hit the tweeter section, so the sound pressure reproduction characteristics have peaks and troughs. It has many characteristics.

Even in the case shown in Figure 3, the sound emitted from the woofer hits the horn, and because the tweeter opening is at the bottom of the cone, the sound pressure reproduction characteristics have many peaks and troughs due to the front chamber effect. It was not possible to obtain a speaker system with flat characteristics.

The object of the present invention is to eliminate the conventional drawbacks and to obtain a coaxial speaker system that has flat sound pressure characteristics and flat phase characteristics in a composite coaxial speaker system.

The present invention will be explained based on the drawings.

FIG. 4 shows a coaxial speaker system of the present invention.

In the figure, the same reference numerals as in FIGS. 2 and 3 indicate the same parts.

21 is a circular planar diaphragm of a tweeter (hereinafter referred to as a tweeter circular diaphragm) of a two-weight speaker system.

), 22 is a ring-shaped circular diaphragm (referred to as a woofer ring diaphragm) of a woofer of a two-weight speaker system.

), 26 is the yoke of the magnetic circuit, and 27.27' is the free edge.

In the present invention, a tweeter circular diaphragm 21 and a woofer ring diaphragm 22 are arranged on the same plane in front of the speaker.

The principle of arrangement of the tweeter and woofer diaphragms of the present invention will be explained next.

FIG. 4 shows a piston vibrating disk placed in an infinite baffle.

When the vibration acceleration of the piston disk is kept constant, the sound pressure characteristics on the axis reproduce flat sound pressure characteristics.

The sound pressure at a point Z Cm ] away from the center of the disk on the axis of the disk is ρ0: density of air ξ.

: Acceleration of the diaphragm α: Radius of the diaphragm Z: Distance from the diaphragm surface: Wave constant ω: Angular velocity In order to coaxially arrange the woofer, squawker, and tweeter with such a piston disk as the diaphragm, the woofer and The diaphragm of the squawker is made into a hollow ring-shaped diaphragm.

FIG. 5 shows a diagram of this ring-shaped diaphragm arranged in an infinite baffle.

Even in a ring-shaped diaphragm in which the piston vibrates, if the vibration acceleration is kept constant, the axial sound pressure characteristics will be constant.

The sound pressure at a point Z [m] away from the surface of the ring-shaped diaphragm is b: Inner diameter of ring diaphragm is given.

FIG. 6 shows a principle diagram of the coaxial speaker system of the present invention in which a disc and a hollow ring-shaped disc are arranged coaxially.

As shown in the figure, the two diaphragm surfaces are arranged so that the woofer section is placed in front of the disk surface of the tweeter section by a distance dl, with the ring-shaped diaphragm surface protruding forward.

At this time, the sound pressure at a point ZI: m) away from the disk surface is at the tweeter section, but at the woofer section, where the subscripts T and w indicate the values at the tweeter section and the Noah section.

In order to match the phases of the high voltages radiated from these two diaphragms, the phase portions 1' and 2' are made equal.

In other words, if dl is selected to satisfy equation (3), a speaker system with flat phase characteristics can be obtained.

The value of 2 is usually a value of 1 to 5 [m].

Also, the sound pressure characteristics are flat. ξT and ξ7 may be determined so as to satisfy the following.

Given the equation (4), if αT and α are 20, then ξT and ξ7 can be easily selected to satisfy.

For 3 Wooi, the distance between the two openings of the diaphragm can be found in the same manner.

For example, the distance dl between the woofer and tweeter diaphragm surfaces
From equation (3), the distance d2 between the squawker and tweeter diaphragm surface is obtained from equation (3), from d1 to d2, attached W → subscript S.
You can find it by changing it to .

As an example of the configuration of the present invention of an actual speaker system, the eighth
and FIG. 9.

Figure 9 shows a three-way composite structure in which a flat diaphragm is placed in the center as a tweeter, a hollow ring-shaped flat diaphragm is placed outside as a squawker, and a hollow ring-shaped flat diaphragm is placed outside as a woofer. 1 shows a structural diagram of a coaxial speaker system.

The distance between the diaphragm surfaces of the tweeter and the woofer and the distance between the diaphragm surfaces of the tweeter and the squawker are values determined by equation (3).

This calculation was performed for a circular shape, but other shapes may be used.

FIG. 10 shows reproduction sound pressure characteristics and phase characteristics with respect to frequency of the coaxial speaker system of the present invention.

In the speaker system of the present invention, the tweeter and the woofer act as a baffle, and the hollow part of the woofer acts as a baffle, so that when this speaker system is installed in a panther, it operates in the same manner as the theory described above.

Therefore, it is possible to obtain a flat axial sound pressure characteristic and a flat sound pressure phase characteristic, which could not be obtained with the conventional composite axial speaker system.

[Brief explanation of drawings]

A conventional 3-way speaker system with a planar array in Fig. 1, Fig. 2 shows a compound axial speaker with a dome-shaped tweeter, Fig. 3 shows a compound axial speaker with a horn-shaped tweeter, and Fig. 4 shows a conventional 3-way speaker system with a planar arrangement. The coaxial speaker system of the present invention, FIG. 5 is a diagram showing a circular plane diaphragm located in a large baffle,
Fig. 5 shows a ring-shaped circular plane diaphragm in an infinite baffle, and Fig. 6 shows a circular plane diaphragm in the tweeter of the present invention and a ring-shaped circular plane diaphragm in the woofer coaxially and with phase characteristics. Figure 7 shows the arrangement of the diaphragms of a two-way speaker arranged with a distance d1 and a front-to-back difference so that the speakers are flat. Figure 8 shows the diaphragm arrangement of a 3-way speaker arranged coaxially and with a distance d□, d2 so that the phase characteristics are flat.
FIG. 9 shows the coaxial speaker system of the present invention as a three-way speaker, and FIG. 10 shows the reproduced sound pressure characteristics and phase characteristics of the speaker system of the present invention. 5.7...Magnetic circuit plate, 6...
・Magnet, 8, 8'... Frame, 9...
... Gasket, 10 ... Cone diaphragm,
12...Voice coil, 13...Damper, 14...Support, 21...Tweeter circular plane diaphragm, 22...Woofer Ring-shaped circular diaphragm, 26...Yoke of magnetic circuit, 27.27'...Free edge.

Claims (1)

[Scope of utility model registration request] 3 consisting of a woofer, squawker and tweeter diaphragm
In the U-KII composite coaxial speaker system, each diaphragm is composed of a flat plate, the tweeter diaphragm for the highest pitch is a circular plate, and the other diaphragms are annular diaphragms. Each diaphragm is arranged in a circular manner with the plate as the center, and the circular diaphragm of the tweeter is placed dl inward from the front surface of the diaphragm of the outermost woofer, and the scope is placed d2 ahead of the tweeter circular diaphragm. diaphragms are provided respectively, and d
2〈dl, distance 1 to 5 on the central axis from the center of the diaphragm
d□s so that the sound pressure characteristics and phase characteristics are flat at m.
The coaxial speaker system that determined d2.