JPH079511Y2 - Speaker unit - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Industrial field of application) The present invention relates to a speaker unit, and particularly proposes a speaker unit with improved low-frequency characteristics in a horn speaker.

(Prior Art) In a conventional general horn speaker, as shown in the vertical side view in FIG. 3, a back cavity 3 is formed between a diaphragm 1 and a bottom yoke 2 behind it. The acoustic impedance viewed from the diaphragm 1 is greatly different between the sound radiation side (horn side) and the back side (magnetic circuit side). (Problems to be solved by the invention) That is, on the sound radiation side, the acoustic resistance converted by the horn 4 is shown, but on the back side, the acoustic capacitance is shown. In and, the acoustic impedance has a phase difference of about 90 degrees.

Moreover, since the resistance on the back side is larger than that on the sound emitting side, the acoustic impedance characteristic of the conventional speaker unit has a large peak in the low frequency range as shown by the dotted line in FIG. As a result, low frequency reproduction is insufficient.

A technique in which a sound absorbing material is provided between the diaphragm and the speaker frame in order to increase the acoustic resistance on the back side of the speaker diaphragm is disclosed in JP-A-56-114499.

The above technique cannot solve the problem due to the 90-degree phase difference between the acoustic impedances of the speaker on the sound emitting side and the rear side.

That is, the standing wave generated in the cabinet cannot be prevented, and the effect of the sound absorbing material can hardly be expected in the low frequency range of about 200 Hz or less.

In addition, in order to make a horn speaker capable of reproducing a relatively wide band, a high range horn is provided on the front side of the diaphragm, and a middle range horn having a filter for cutting the high range is provided on the rear side. Japanese Utility Model Publication No. 56-45271 discloses a structure in which a main body of a use horn is bent and its opening is directed to the same front side as a high frequency horn.

With the above structure, the same effect as providing two horn speakers with different bands can be obtained, but there is no action to make the acoustic loads on the front side and the back side of the diaphragm substantially equal,
Moreover, in the low range, the sound of the middle range horn interferes with the sound emitted from the high range horn to generate a peak, which makes efficient reproduction in a sufficiently low range difficult.

(Means for Solving Problems) The present invention is devised so as to enable efficient reproduction in a sufficiently low low range, and the structure thereof is the sound on the front side of the speaker diaphragm 1. In order to make the dynamic load and the acoustic load on the back side of the speaker diaphragm 1 substantially equal, the back horn 6 is formed on the back side of the speaker diaphragm 1, and the sound absorbing material 9 is provided in the opening 8 of the back horn 6. Is filled, and the outside of the opening 8 is surrounded by a box 10 and hermetically sealed.

(Function) A rear horn 6 is provided on the rear side of the speaker diaphragm 1,
Since the acoustic load on the front side of the speaker diaphragm 1 and the acoustic load on the back side of the speaker diaphragm 1 are made substantially equal, the acoustic phase difference between the front side and the rear side disappears, and the horn 4 The characteristic disturbance due to the standing wave based on the shape is reduced.

Since the acoustic loads on the front side and the rear side of the diaphragm 1 are substantially the same, the movements of the diaphragm 1 in the front-rear direction are substantially the same, and the linearity of the acoustic characteristics is good.

Moreover, when the speaker diaphragm 1 vibrates toward the back side, the sound transmitted by the back horn 6 is absorbed by the sound absorbing material 9 filled in the opening 8 of the back horn 6, and the opening Since the box 10 that surrounds the outside of 8 seals the sound radiated to the front side and eliminates the peak in the low frequency range, efficient reproduction in the low frequency range is possible. Is possible.

(Embodiment) Next, an embodiment of the present invention applied to a horn speaker exemplified by a vertical side surface in FIG. 1 will be described.

Rear horn 6 with throat 5 on the back of diaphragm 1
Is attached to the bottom yoke 7, and the opening 8 of the rear horn 6 is attached.
Is filled with a sound absorbing material 9, and the outside of the opening 8 is surrounded by a box 10 to be hermetically sealed. The load is substantially equal to the acoustic load of the horn 4 viewed from the diaphragm 1, and the load is the rear horn 6 and the opening 8. The rear speaker unit 11 consisting of the sound absorbing material 9 and the box 10 filled in is obtained.

Reference numeral 12 is a voice coil, reference numeral 13 is a magnet, and reference numeral 14 is a top plate.

With the above configuration, when the diaphragm 1 vibrates toward the back side, the sound transmitted by the back horn 6 is absorbed by the sound absorbing material 9 filled in the opening 8 of the back horn 6, and the opening is opened. The box 10 that surrounds the outside of the portion 8 and seals it prevents interference with the sound emitted to the front side.

Thus, the load of the rear speaker unit 11 including the rear horn 6, the sound absorbing material 9 filling the opening 8 and the box 10 eliminates the peak in the low frequency range as illustrated by the solid line in FIG. Therefore, efficient reproduction in a sufficiently low low range is possible, and acoustic loss due to contact and adhesion between the diaphragm and the sound absorbing material as in the prior art does not occur.

Although not shown, this invention can be applied to a dome speaker by providing a rear horn as in the case of the horn speaker.

(Effect of the Invention) As described above, the speaker unit according to the present invention is provided with the rear horn 6 on the rear side of the speaker diaphragm 1, and the acoustic load on the front side of the speaker diaphragm 1 and the rear side of the speaker diaphragm 1. The acoustic load difference between the front side and the back side is eliminated, and the characteristic disturbance due to the standing wave due to the shape of the horn 4 is reduced.

Since the acoustic loads on the front side and the rear side of the diaphragm 1 are substantially the same, the movements of the diaphragm 1 in the front-rear direction are substantially the same, and the linearity of the acoustic characteristics is good.

Moreover, when the speaker diaphragm 1 vibrates toward the back side, the sound transmitted by the back horn 6 is absorbed by the sound absorbing material 9 filled in the opening 8 of the back horn 6, and the opening Since the box 10 that surrounds the outside of 8 seals the sound radiated to the front side and eliminates the peak in the low frequency range, efficient reproduction in the low frequency range is possible. Therefore, the acoustic loss due to the contact and adhesion between the diaphragm and the sound absorbing material as in the prior art does not occur.

[Brief description of drawings]

1 is a vertical sectional side view of a speaker unit showing an embodiment of the present invention, FIG. 2 is a characteristic diagram of the speaker unit of FIG. 1, and FIG. 3 is a vertical sectional side view of a conventional speaker unit. . 1 ... Speaker diaphragm, 6 ... Rear horn 6, 8 ... Opening 9 ... Sound absorbing material, 10 ... Box

Claims (1)

[Scope of utility model registration request] 1. An acoustic load on the front side of a speaker diaphragm,
In order to make the acoustic load on the back side of the speaker diaphragm approximately equal, a back horn is formed on the back side of the speaker diaphragm, and the opening of the back horn is filled with a sound absorbing material. A speaker unit characterized by being enclosed in a box and sealed.