JPH048716Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to an electrodynamic speaker having a passive diaphragm in the field of electroacoustic equipment.

[Conventional technology]

In order to expand the reproduction band of the cone speaker, a corrugation 22 is provided near the inner circumference of the cone diaphragm 21, as shown in FIG. There is a speaker configured so that the vibration is not transmitted to the outer periphery of the diaphragm 21, but remains inside the corrugation 22, the effective mass of the diaphragm is reduced, and the conversion efficiency in high frequencies is increased.

[Problems to be solved]

In the above cone speaker, the diaphragm 2
The part outside the corrugation 22 of 1 is not a rigid body that can be considered a lumped constant, but has the property of being extremely susceptible to split vibration, so even a small amount of driving force applied to the inner circumference causes split resonance, which changes the frequency characteristics. This was a cause of deterioration of transient characteristics.

[Means for solving problems]

Except for the drawbacks of the conventional example described above, the speaker of the present invention is an electrodynamic type speaker, as shown in the embodiment of FIG. A first diaphragm 1 to which a voice coil bobbin 3 is coupled at the center, a high frequency reproducing section 2a at the center and a low frequency reproducing section 2b attached at the front of the first diaphragm 1 have a compliance 2c. a second diaphragm 2 integrally coupled with a frame 8 supporting the first diaphragm 1 and the second diaphragm 2 with a space therebetween;
and an airtight chamber surrounded by the rising side wall between the first diaphragm 1 attachment part and the second diaphragm 2 attachment part of the frame 8, and the first diaphragm 1 and the second diaphragm 2. 4 is formed, and the high frequency reproduction section 2a of the second diaphragm 2 is coupled to the voice coil bobbin 3 by an extension bobbin 5.

[Effect]

In a speaker having a vibration system with such a configuration, the first diaphragm 1 and the second diaphragm 2 vibrate as one in the low frequency range, but the resonance frequency due to the compliance of the low frequency reproduction section 2b and the airtight chamber 4 is If it is set low, frequencies lower than the system's resonant frequency will be reproduced. Next, in a band where the compliance of the airtight chamber 4 and the compliance 2c of the second diaphragm 2 act as a high frequency cutoff filter, the low frequency reproduction section 2b does not vibrate, only the high frequency reproduction section 2a vibrates, and the middle and high frequency regions Radiates range sound. At this time,
The low frequency reproducing section 2b does not vibrate at all, and therefore there is no adverse effect due to divided vibration.

Therefore, in the speaker as a whole, in the low range, the entire surface of the low range reproducing part 2b is driven by the air in the airtight chamber 4 and the high range reproducing part 2a, and in the middle and high ranges, only the high range reproducing part 2a is driven. The piston vibrates completely in the entire range.

〔Example〕

In FIG. 1, reference numeral 1 denotes a first diaphragm, and a voice coil bobbin 3 is coupled to the center thereof, and a voice coil 6 is wound around the lower end of the voice coil bobbin 3, so that the voice coil 6 is located in a magnetic gap. It is supported in frame 8 at edges 7. Similar to general speakers, a damper (not shown in the figure) may be used in conjunction with the speaker if necessary. In the figure, the first diaphragm 1 is of a flat plate type, but it is not limited to this, and may be of a cone type.

Reference numeral 2 denotes a second diaphragm, in which a high frequency reproducing section 2a and a low frequency reproducing section 2b in the center are integrally configured via a compliance 2c, and the first diaphragm in the same frame 8 is connected via an airtight chamber 4. In front of the diaphragm 1, supported by the edge 9, a rising side wall portion between the first diaphragm 1 attachment part and the second diaphragm 2 attachment part of the frame 8, the first diaphragm 1, and the second diaphragm. An airtight chamber 4 surrounded by 2 is formed.

Further, the high frequency reproducing section 2a of the second diaphragm 2 is coupled to the voice coil bobbin 3 by an extension bobbin 5, and the driving force generated in the voice coil 6 is directly transmitted.
Although the shape of the second diaphragm 2 is not limited either, by making the high frequency reproducing section 2a into a dome shape as shown in the figure, it is possible to cause the piston to vibrate in a wide range of bands.

〔effect〕

Figure 3 shows the frequency characteristics of the speaker of the present invention. The speaker diameter is 20 cm, and the diameter of the high frequency reproduction section of the second diaphragm is 60 mm. The overall structure is the same as the embodiment shown in FIG.

The cutoff frequency of the low frequency reproduction section is approximately 400Hz, and at frequencies above that, it exhibits extremely flat characteristics up to around 10kHz, and as explained in the operation section, it can be used over a wide band even though it is a single unit speaker. It is clear that the piston vibrates, and it is possible to easily obtain a speaker with excellent frequency characteristics and transient characteristics without requiring a network or the like like a two-way speaker.

[Brief explanation of drawings]

FIG. 1 is a sectional view of the speaker of the present invention, FIG. 2 is a sectional view of a conventional general speaker, and FIG. 3 is a frequency characteristic diagram. 1 is a first diaphragm, 2 is a second diaphragm, 3 is a voice coil bobbin, 4 is an airtight chamber, and 5 is an extension bobbin.

Claims (1)

[Scope of utility model registration request] In an electrodynamic speaker, a first diaphragm 1 to which a voice coil bobbin 3 is coupled at the center;
A second diaphragm 2 that is attached in front of the first diaphragm 1 and in which a high frequency reproduction section 2a in the center and a low frequency reproduction section 2b in the surrounding area are integrally coupled by a compliance 2c, and the first diaphragm 1. The frame 8 has a frame 8 that supports the first and second diaphragms 2 with a space therebetween, and a rising side wall portion between the first diaphragm 1 attachment portion and the second diaphragm 2 attachment portion of the frame 8. 1 diaphragm 1
In addition, an airtight chamber 4 surrounded by the second diaphragm 2 is formed, and a high frequency reproduction section 2 of the second diaphragm 2 is formed.
A speaker characterized in that a is connected to the voice coil bobbin 3 by an extension bobbin 5.