JPH1032896A - Electroacoustic transducer with amplifier circuit - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electroacoustic transducer which does not generate a distortion sound that results from a signal clip during reproducing sound, even without using an amplifier whose maximum output is large in reproduction of a signal in high dynamic range, which is inexpensive and which also has high performance. SOLUTION: This device consists of a compound driven electroacoustic transducer 1 which contains plurality of voice coils M1, M2,..., plurality of amplifiers A1, A2,... which are connected to plurality of voice coils M1, M2,... respectively and clip extracting circuits C1,... which are connected to an output circuit of each amplifier, except the amplifier on the last stage among plurality of amplifiers A1, A2,... and extracts a clip component from respective output signals. When a clip component in an output signal of the connected amplifiers A1,... exists, the circuits C1,... extract the clip component and are connected to the amplifiers A2,... on the next stage to input it. The transducer 1 is a single dynamic loudspeaker which contains plurality of voice coils in a single vibration system, and plurality of normal dynamic loudspeakers may also be used instead.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an electro-acoustic transducer with an amplifier circuit, which uses an electro-acoustic transducer having a plurality of driving sections, applies a normal signal to one driving section, and uses an amplifier for clipping. The present invention relates to an electro-acoustic converter with an amplifier circuit that extracts a clip component and applies the clip component to another driving unit from a separately provided amplifier to compensate for a missing signal due to the clip.

[0002]

2. Description of the Related Art As is well known, when a loudspeaker is driven by an amplifier, an abnormal sound is generated from the loudspeaker if the amplifier clips when the signal has a large amplitude. This is because the waveform is distorted by clipping the signal, and high-order higher harmonic components are mixed in the reproduced sound as distortion components. Conventionally, in order to prevent such a phenomenon, a limiter circuit is inserted in the input section of the amplifier to suppress the amplitude of the input signal when the amplitude is large so as not to clip.

[0003]

In the above-described conventional clip preventing means, if the amplitude limit characteristic of the limiter circuit to be used is too steep, the result is the same as that obtained by clipping by the amplifier, and clipping distortion occurs. ,
In order to avoid this problem, the limiter operates gradually, but as a result, the dynamic range of the signal becomes narrower, and the limiter also acts on the small amplitude part sandwiched between the large amplitude parts. There is a disadvantage that the maximum output of the amplifier is not fully utilized, and in order to ensure a sufficient dynamic range without clipping, an amplifier having a large maximum output must be used.
There is a problem to be solved, which is uneconomical for normal use.

In order to solve the above-mentioned conventional problems, the present invention extracts a signal component from a main amplifier when the signal clip occurs and amplifies the signal component separately.
By inputting the signal to the electro-acoustic transducer together with the signal of the main amplifier and reproducing the signal, even in the reproduction of a signal having a high dynamic range, an amplifier having a large maximum output is used as the main amplifier. It is an object of the present invention to provide an electroacoustic conversion device that does not reproduce a distorted sound caused by a signal clip during a reproduced sound even if it is not.

[0005]

Means for Solving the Problems The electroacoustic transducer with an amplifier circuit according to the present invention for achieving the object will be described by using the reference numerals used in the description of the embodiments. , M voice coil M1, M2,..., Mn, and n voice coil M1, M2,..., Mn connected to each of the n voice coils M1, M2,. , An and the amplifiers A1, A2,..., A (n-n) up to the (n-1) th amplifier among the amplifiers A1, A2,.
Clip extraction circuits C1, C2,..., C connected to the respective output circuits of 1) and extracting clip components from the respective output signals.
(N-1), and the clip extraction circuits C1, C
2,..., C (n−1), if there is a clip component in each output signal of the amplifiers A1, A2,. It is configured to be connected so that it is extracted and input to the next-stage amplifier.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In implementing an electroacoustic transducer with an amplification circuit having such a configuration, a case where n = 2, that is, two voice coils will be described as an example with reference to FIGS. The electroacoustic transducer 1 has a basic structure similar to a well-known dynamic speaker, in which a driving unit M is wound around a first voice coil M1 and a second voice coil M2 on a common winding frame Bo. The drive system M is fixed to the center of the diaphragm Di such that the first coil M1 and the second coil M2 can vibrate without contacting the magnetic gap of the magnetic circuit G. , A structure supported by an edge Ed inside the frame Fr.

The amplifier circuit for driving the electroacoustic transducer 1 includes a first amplifier A1, a clip extracting circuit C1 for extracting a clip component, and a second amplifier A2. An ordinary power amplifier amplifies the input signal Vi and applies it to the first coil M1 of the electroacoustic transducer 1 as a main signal output Vo1.

The clip extracting circuit C1 uses two operational amplifiers C11 and C12. One of the operational amplifiers C11 has an output whose main signal output Vo1 has the same level as the input signal Vi by dividing resistors R1 and R2. The comparison signal Vi2 is input with a positive polarity, the output of the operational amplifier C11 is divided and input to the other operational amplifier C12 with a negative polarity, and the input signal Vi (=
Similarly, by inputting Vi1) to the operational amplifier C12 with a positive polarity, the output comparison reference signal Vi2 is compared with the input signal Vi to extract the distortion component voltage Vi3 generated by the clipping of the first amplifier A1. Amplify with 2 amplifier A2,
The clip component Vcl is applied to the second coil M2 of the electroacoustic transducer 1.

For reference, the waveforms of the input signal Vi, the output comparison reference signal Vi2 and the distortion component voltage Vi3, and the waveforms of the main signal output Vo1 and the clip component output Vo2 are described in the corresponding portions in FIG. ing. In the figure,
The values of the resistances R4 to R9 of the clip extraction circuit C1 are set as follows: resistance R4 = resistance R5 = resistance R6 = resistance R7, resistance R8 =
Assuming that the resistance is R9 and the amplification degrees of the amplifiers A1 and A2 are both Ao, Vi3 = Vi1-Vi2 = Vi-Vo1R2 / (R1 + R2) R2 / (R1 + R2) = 1 / Ao, Vi3 = Vi -Vo1 / Ao When the amplifier A1 clips, the main signal output Vo1 becomes a signal lacking the clip component output Vo2 (= Vcl) from the non-clipped main signal output (= Vi.Ao), so that Vo1 = Vi.Ao. −Vcl∴Vi3 = Vi− (Vi · Ao−Vcl) / Ao = Vcl / A
o∴Vo2 = Vi3 · Ao = Vcl, and the driving unit M of the electroacoustic transducer 1 generates a driving force corresponding to Vo1 + Vo2 = Vi · Ao, ie, a non-clipped main signal output.

In other words, with such a structure, the input signal Vi has a large amplitude and the first amplifier A1
When clipping is performed, the main signal output V in which the clip component Vcl is absent in the voice coil M1 of the electroacoustic transducer 1.
The clip component Vcl flows into the voice coil M2 simultaneously with the clip component Vcl, and generates the same driving force as if the unclipped main signal output in which the input signal Vi was directly amplified was applied to the drive unit M. Therefore, the vibration system of the electroacoustic transducer vibrates with a sufficient amplitude while emitting the original signal waveform, and emits sound with a normal dynamic range.

If the dynamic range of the input signal Vi is even greater and the second amplifier A2 causes clipping, a second clip extraction circuit C2 is connected to the output of the second amplifier A2, and this clip extraction is further performed. A third amplifier A3 is connected to the output of the circuit C2 and these three amplifiers are connected to three.
This is handled by connecting to the electroacoustic transducer 1 having the voice coils M1, M2, and M3. In this case, in the above description of the means for solving the problem, (n =
This corresponds to 3).

When the first amplifier A1 does not clip, the distortion component voltage Vi3 is not extracted, and the second amplifier A2 does not operate. The second amplifier A2 amplifies only the clip component Vcl. In particular, in the case of music reproduction using a bass-only speaker having a large dynamic range, the clip component has a low frequency in terms of time and level. It does not require a thermal design for high power.

[0013]

FIG. 1 is a circuit diagram of a first embodiment of the simplest and basic structure corresponding to the case of (n = 2), and FIG. 2 is an electroacoustic transducer in the first embodiment. FIG. 3 is a sectional view of FIG.
FIG. 9 is an explanatory diagram of a modification of the first embodiment.

In FIGS. 1 and 2, an amplifier A1, an amplifier A2, an operational amplifier C11, and an operational amplifier C12 in an amplifier circuit associated with the electroacoustic transducer 1 of the first embodiment.
In each case, an amplifier having a structure often used is used.
Since the amplifier A1 may perform a clip operation, the power may be smaller than that of a conventional amplifier of the same level. Particularly, since the amplifier A2 amplifies only the clip component, the frequency of the clip component is temporally and levelly. Because it is small, thermal design for large power is not required. According to the experimental results, the thermal design of the power amplification section and the power supply section can be almost equal to the case of only the amplifier A1. When the power supply voltages of the amplifiers A1 and A2 are equal, the so-called music power is equal to the power of the amplifier A1. Double.

As shown in FIG. 2, the electroacoustic transducer 1 has a basic structure similar to a dynamic speaker having a well-known structure, and a driving unit M uses a first voice coil M1 and a second voice coil M2 in common. A vibrating system in which the drive unit M is fixed to the center of the diaphragm Di and has a structure in which the first coil M1 and the second coil M2 are fixed to the magnetic gap In order to be able to vibrate without contacting the inside, the frame Fr has a structure supported by an edge Ed inside the frame Fr.
To the first voice coil M1 and the second voice coil M2.
Can be considered as an aggregate of voice coils of a conventional structure wound around separate winding frames Bo and fixed to a common (for example, oval) diaphragm.

FIG. 3 shows a modification of the first embodiment shown in FIG. 1, in which the electroacoustic transducer 1 is an aggregate of speakers S1 and S2 each having a single voice coil.
Therefore, the voice coil M1 is mounted on the speaker S1, and the voice coil M2 is mounted on the speaker S2. The amplifier A1 is connected to the speaker S1, and the amplifier A2 is connected to the speaker S2. In this modification, the dynamic speaker having the conventional structure can be used as it is, so that it is easy and inexpensive as a device, and it is easy to increase the overall effective area of the diaphragm. It has features that are structural. Also, in FIG. 3, the speakers S1, S2
Is attached to one cabinet Ca, but the same applies to the case where independent cabinets are provided for individual speakers, and it goes without saying that both are within the scope of the present invention (not shown).

FIG. 4 shows the structure of the second embodiment. In the second embodiment, the number of divisions of the clip level is changed from three in the first embodiment to three, and corresponds to the case of (n = 3). The structure of the amplifying circuit portion is obtained by expanding the structure of the first embodiment to three stages. A second clip extracting circuit C2 is connected to the output of the second amplifier A2. Section, a third amplifier A3 is connected, and these three amplifiers are connected to three voice coils M1, M2, M3.
Are connected to the electroacoustic transducer 1 each having a driving portion. A configuration in which the structure of the second embodiment is further expanded to multiple stages is also conceivable. In general, when the structure of the second embodiment is n stages, the clip extraction circuit is connected to the (n−1) th stage amplifier, and the clip extraction circuit ( The clip component output by (n-1) is input to the final stage amplifier n. Such a configuration expanded in multiple stages also belongs to the scope of the present invention.

An electroacoustic transducer 1 according to a second embodiment.
Represents the three voice coils M as shown in FIG.
A structure having one diaphragm in which 1, M2, and M3 are wound around a common winding frame Bo may be used. However, as in the modification of the first embodiment, three voice coils are distributed to three speakers. It is practical to adopt a structure in which a common cabinet or individual speakers are attached to the cabinet. FIG. 5 shows a structure corresponding to this modification, which is individually attached to the cabinet Ca.

Although the embodiments and modifications which are considered to be representative of the present invention have been described above, the present invention is not necessarily limited to the structures of these embodiments and modifications, and the present invention is not limited thereto. The present invention has the structural requirements, achieves the object of the present invention, and can be appropriately modified and implemented within a range having the following effects.

[0020]

The electroacoustic transducer with an amplification circuit according to the present invention comprises a main amplifier and an amplifier for amplifying only a clip component when the main amplifier is clipped, and uses these two amplifiers. To operate an electroacoustic transducer having a plurality of driving units. Therefore, the dynamic range is expanded, and deterioration of sound quality due to clipping can be prevented.

Also, the main amplifier does not need to consider much the influence of clipping on the high-level portion of the music signal having a low time rate, so that the maximum output of the conventional amplifier in consideration of the dynamic range is not necessary. There is no need to use a large amplifier.

In particular, an amplifier that amplifies only the clip component consists only of the distortion component caused by clipping in the high-level portion of the signal, and is less frequent in terms of time and level. Further, an amplifier having a small output may be used. Therefore, the thermal design of the power supply circuit can be made substantially the same as that of only the main amplifier, so that only a small amplifier for amplifying only the clip component and two operational amplifiers and a few resistors are added to each small amplifier. Along with the miniaturization of the main amplifier, the manufacturing cost is reduced,
The effect was that the sound quality could be improved efficiently.

[Brief description of the drawings]

FIG. 1 is a circuit diagram illustrating a configuration of a first embodiment.

FIG. 2 is a cross-sectional view of the electro-acoustic transducer of FIG.

FIG. 3 is an explanatory diagram of a modification of the first embodiment.

FIG. 4 is a circuit diagram showing a configuration of a second embodiment.

FIG. 5 is an explanatory diagram of a modification of the second embodiment.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Electroacoustic converter S1 Electrodynamic speaker S2 Electrodynamic speaker S3 Electrodynamic speaker M Drive M1 Voice coil M2 Voice coil M3 Voice coil Bo Reel Di Di diaphragm G Magnetic circuit Fr Frame Ed Edge Ca Cabinet A1 Amplifier A2 Amplifier A3 Amplifier C1 Clip component extraction circuit C2 Clip component extraction circuit C11 Operational amplifier C22 Operational amplifier

Claims (3)

[Claims] 1. An n number of voice coils (M1), (M2),
, (Mn), and a combined drive type electroacoustic transducer (1), and the n voice coils (M1), (M2),
.., (Mn) are connected to n amplifiers (A
1), (A2),..., (An) and (n)
-1) amplifiers (A1), (A2), ..., (A)
(N-1)) is connected to each output circuit and extracts a clip component from each output signal.
1), (C2),..., (C (n−1)), and the clip extraction circuits (C1), (C2),.
1)) are each of the amplifiers (A
1) If a clip component exists in each output signal of (A2),..., (A (n−1)), the clip component should be extracted and connected to be input to the next-stage amplifier. An electroacoustic transducer with an amplification circuit, characterized by the following. 2. An electroacoustic transducer (1) comprising a driving unit (M) in which n voice coils (M1), (M2),..., (Mn) are wound around a common bobbin (Bo). 2. The electro-acoustic transducer with an amplification circuit according to claim 1, wherein the single electro-dynamic speaker has a composite voice coil including a magnetic circuit (G) and a diaphragm (Di). 3. The electroacoustic device with an amplifying circuit according to claim 1, wherein said electroacoustic transducer (1) is an aggregate of a plurality of electrodynamic speakers (S1), (S2),..., (Sn). Conversion device.