JPS597832Y2 - Speaker system with multiple electrodynamic speakers - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a speaker system having a plurality of electrodynamic speakers designed to reduce high-frequency distortion, particularly second harmonic distortion, as much as possible.

As is well known, general-purpose electrodynamic speakers generate harmonic distortion, and one of the causes of this generation is current distortion in the magnetic circuit.

This is because when the voice coil moves within the magnetic gap due to electrical input, the current flowing through the voice coil is distorted due to magnetic nonlinearity in the vicinity of the coil, which distorts the radiated sound and generates harmonic distortion.

However, conventionally, in a speaker system using multiple electrodynamic speakers, all speakers (two in the figure) A and B are mounted in a cabinet C with all speakers A and B facing the same direction, as shown in Figure 1. along with two speakers A and B
Since the two voice coils were connected in series or parallel so that the diaphragms vibrated in the same direction, the harmonic distortion rate of the two speaker forces A and B is as follows: There was almost no difference.

In addition, as shown in Fig. 2, in order to reduce the harmonic distortion rate, speakers (two in the figure) D, which vibrate in the same phase,
E is installed in cabinet F so that it faces in opposite directions and vibrates in antiphase, and two speakers D
, E were connected in series or in parallel, so the air pressure inside the cabinet F remained constant and distortion could not be removed sufficiently.

The harmonic current distortion characteristics of this conventional example are shown in Fig. 4, and
The high frequency characteristics are shown in Figure 5 (all characteristics tables are for bass reflex type).

In the above characteristic chart, ■ is the basic current characteristic, II is the second harmonic current distortion characteristic, X is the basic characteristic, and Y is the second harmonic distortion characteristic, but the second harmonic distortion characteristic Y is 20 Only db,
Further, the second harmonic distortion characteristic II of the current distortion is shown higher by 30 db.

The purpose of the present invention is to reduce the distortion of the conventional example as described above.

In other words, in a speaker system with multiple electrodynamic speakers installed in a closed cabinet, half of the even number of speakers face the front side toward the sound emission direction, and the other half of the speakers face the rear side. By mounting the speakers facing the sound emission direction and connecting each voice coil so that the polarities of each half of the speakers are opposite to each other, current distortion caused by magnetostriction caused by the relationship between the magnetic circuit and the voice coil can be reduced. The aim is to reduce harmonic distortion, especially second harmonic distortion, as much as possible by canceling each other out.

To describe the invention in detail by means of an illustrated embodiment, FIG.
In the embodiment of the present invention, an even number (two in the figure) of speakers 1a whose magnetic circuit and voice coil have the same structure
and 1b are divided into two, and each speaker la and lb are attached to the front side of the diaphragm, that is, to the full 2a of the closed cabinet 2 so that the opening directions are opposite to each other.

Therefore, one speaker 1a is mounted with the front side facing the sound emission direction O like a normal speaker, whereas the other speaker 1b is mounted with the rear side facing the sound emission direction O.

The diaphragms of the above speakers 1a and 1b are
Input terminals 3 and 4 of each voice coil are connected so that when one swings toward the front, the other swings toward the rear.
They are connected in series as shown by solid lines, in parallel or series-parallel as shown in dotted lines, etc., so that they have opposite polarities. 5 is a connecting wire, and 6 is an input terminal.

That is, the directions of the currents flowing through the voice coils of both speakers la and 1b are connected so that the voice coils receive forces from the magnetic circuit in opposite directions.

Further, the rear side of the speaker 1a and the front side of the speaker 1b are provided with a shielding structure so that no sound is emitted.

Next, the operation of the present invention will be explained.

When electrical input is applied to input terminal 6, both speakers 1a and 1
The diaphragm b vibrates in the same direction as the sound emission direction O.

That is, when the diaphragm of the speaker 1a swings toward the front side in the sound emission direction O, the other speaker 1b swings toward the rear side in the sound emission direction O, so that the fundamental waves are multiplied and increase.

On the other hand, since both speakers 1a and 1b have opposite polarities, both voice coils move in opposite directions in relation to the magnetic gap, and a current is generated from the relationship between the magnetic circuit and the voice coil. Distortion is canceled and the second harmonic is greatly reduced relative to the fundamental.

The experimental characteristics are shown in FIG. 6 as a harmonic wave distortion characteristic and FIG. 7 as a harmonic distortion characteristic.

In the characteristic diagram, ■ is the basic current characteristic, II is the second harmonic distortion characteristic of current distortion, X is the basic characteristic, and Y is the second harmonic distortion characteristic, but the second harmonic distortion Y is 20 db. , and the second harmonic distortion characteristic II of the current distortion is shown higher by 30 db.

Incidentally, if a short ring made of copper or the like is provided on the balls in the magnetic circuits of the speakers 1a and 1b, the third harmonic distortion can be reduced together.

As mentioned above, in the present invention, of the even number of speakers installed in the closed cabinet 2, half of the speakers 1a have their front sides facing the sound emission direction O, and the other half of the speakers 1b have their rear sides emitted. This is a speaker system having a plurality of electrodynamic speakers, characterized in that the speakers 1a and 1b are mounted in direction O, and each half of the speakers 1a and 1b are connected to each other so that their respective voice coils have opposite polarities. .

Therefore, when the diaphragm of one speaker 1a swings toward the front side, which is the sound emission direction O, the other speaker 1b also swings toward the rear side, which is the sound emission direction O. Therefore, both speakers 1a and 1b They will vibrate in the same direction, and the fundamental waves will be synergized and will not cancel each other out and be distorted.

On the other hand, since both speakers 1a and 1b have opposite polarities, both voice coils move in opposite directions in relation to the magnetic gap, and a current is generated from the relationship between the magnetic circuit and the voice coil. The distortion is canceled and the second harmonic is greatly reduced relative to the fundamental.

That is, according to the present invention, harmonic distortion, particularly second harmonic distortion, can be reduced as much as possible without affecting the fundamental wave.

The present invention can be applied to any speaker system that uses an even number of speakers, whether it is a cone type or a horn type, and is applicable to any speaker system that uses an even number of speakers. Of course, the present invention can also be applied to a speaker system using a plurality of speakers such as a tone sieve.

[Brief explanation of the drawing]

FIGS. 1 and 2 are cross-sectional views showing a conventional speaker system, FIG. 3 is a cross-sectional view showing an embodiment of the speaker system according to the present invention, and FIG. 4 is a cross-sectional view of a conventional speaker system. FIG. 5 is a chart showing harmonic current distortion characteristics of a conventional example, FIG. 6 is a chart showing harmonic current distortion characteristics according to an illustrated embodiment of the present invention, and FIG. It is a chart showing harmonic distortion characteristics of an example. la, lb...Speaker, O...Sound emission direction.

Claims (1)

[Scope of utility model registration request] Of the even number of speakers installed in a closed cabinet, half of the speakers are installed with the front side facing the sound emission direction, and the other half of the speakers are installed with the rear side facing the sound emission direction. A speaker system having a plurality of electrodynamic speakers, characterized in that each voice coil is connected to have opposite polarity.