JPS6024635B2 - sound reproduction device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a sound reproducing device, and more particularly to a sound reproducing device that is capable of reproducing sound with an appropriate balance for each range in a low-mid range and a treble range.

In general, in sound reproduction apparatuses, signals are operated in a so-called amplitude form throughout the system, as shown in FIG. 1, which shows a typical example of a disk record reproduction system. In other words, a signal converted into an amplitude component by a cartridge 11 such as an electrostatic type is obtained, and this signal is directly transmitted via a front layer amplifier 12, an equalizer circuit 13, and a main amplifier 14 to an electromagnetic speaker 15 such as a moving coil type. is applied to obtain acoustic (reproduction) output. However, in a system that handles the entire system as an amplitude signal, it is particularly susceptible to the influence of time component signals such as distortion and noise components generated in the amplifier in the signal transmission system. It has some drawbacks.

In addition, recently, electrostatic speakers have been developed as speakers that are excellent at reproducing high-pitched sounds, but the electrostatic speakers are used as they are in place of the electromagnetic speaker 5 in the reproduction system shown in Figure 10. If so, the amplifier 14 is likely to be destroyed because the impedance decreases too much in the Takagi frequency region, and if a protective resistor is inserted to prevent this, the treble reproduction characteristic, which is a characteristic of an electrostatic type speaker, will be damaged. It had the disadvantage that it was damaged.

Therefore, this invention was made in view of the above points, and in addition to directly reproducing the low-mid range part with an electromagnetic speaker, the output part including the electrostatic speaker after performing differential processing on the high range part. It is an object of the present invention to provide a sound reproducing device which can perform reproduction with an appropriate balance for each range by performing integral processing.

DESCRIPTION OF THE PREFERRED EMBODIMENTS A basic example of a sound reproduction device according to the present invention will be described in detail below with reference to the drawings.

That is, FIG. 2 shows a disc record playback system as an example, and if the cartridge is an electrostatic type and is given as an amplitude signal, the audio signal from the cartridge 21 is passed through the differentiating circuit 22, and then to the cartridge 21. For example, when the signal is of an electromagnetic type and is given as a velocity signal, it is directly supplied to the amplifier 23.

Here, the amplifier 23 includes an equalizer circuit as necessary and has an output impedance close to that of a constant resistance R type. However, when using an existing amplifier, a static resistance is connected via a separately external resistor R. It is connected to an electric speaker 24. Therefore, in any case, in such a disc record playback system, the signal up to the amplifier in the signal transmission system is operated as a speed-type signal, so it is difficult to understand the time components such as noise components and distortion generated in the amplifier. This is done so that it is not affected by the signal as much as possible.

In other words, a velocity type signal is a signal obtained by differentiating the amplitude component of an amplitude type signal as an audio signal proportional to the amplitude obtained from an electrostatic type cartridge by a time component using a differentiating circuit. This is because, in principle, when using a cartridge, a speed-type signal generated in the cartridge is directly given. Due to this fact, at least when using an electrostatic cartridge, an equalizer circuit as a compensation circuit for removing unnecessary signals (distorted waves, unnecessary frequency waves, etc.) generated in the cartridge itself is not included in the amplifier. It is enough. In addition, the signal that has been operated as a velocity type signal in this way has a (constant) resistance component R at the output section of the amplifier 23 and a capacitance component C at the electrostatic speaker 24, for example, near the lower limit of the reproduction band or below. This is because an integral action with a time constant corresponding to . In order to prevent the impedance from decreasing too much in the Takagi frequency region, the matching between the two is made appropriate to provide a protective effect for the amplifier. This is something that can be fully demonstrated.

Note that when connecting an electrostatic speaker to the output end of the amplifier in the above, a step-up transformer 25 may be inserted as shown in FIG. Therefore, part of the winding resistance of the transformer may be used, and the resonance phenomenon caused by the inductance component L of the transformer and the capacitance of the electrostatic speaker is suppressed by the resistance component R, and the reproduction is improved. Deterioration of sound quality can be prevented.

Furthermore, if you have difficulty using an electrostatic speaker, you may replace it with an electrostatic headphone, and any electroacoustic transducer may be sufficient. Furthermore, another advantage of this invention as described above is that the influence of distortion and noise components within the amplifier is minimized, which improves the S'N of the entire system including the first stage amplification element. However, it can also contribute to improving dynamic characteristics.

Further, since a part of the amplifier, an equalizer circuit, etc. can be omitted, the circuit configuration can be simplified, and furthermore, deterioration of characteristics due to these can be prevented. In addition, adding an integral action to the (constant) resistance component R at the amplifier output section and the capacitance C of an electrostatic speaker, etc. is equivalent to inserting a low-pass filter, so this eliminates the need. This prevents deterioration of reproduced sound quality by reducing frequency wave leakage as much as possible, and further protects the electrostatic loudspeaker itself. By the way, in the above, when large amplitude components at low frequencies are simultaneously reproduced, nonlinear distortion occurs in the amplifying element etc. due to saturation by the large amplitude components, but generally the (voltage) amplitude spectrum at high frequencies is Since it is very small, this does not cause saturation.

Therefore, the present invention is particularly related to this point, and generally the level of each frequency range of sound field reproduction is very small in the high frequency range, that is, it is not necessary to have a sound pressure, but a balance commensurate with each range as a level is required. The aim is to provide a sound reproducing device that uses a single amplifier to separately reproduce a low-mid range playback system and a high-pitched sound playback system. .

That is, in FIG. 4, the signal from the cartridge 21 shows a certain characteristic as shown in FIG. As shown in FIG.
An electrostatic speaker 241 is connected via the . The electromagnetic type speaker 26, such as a moving coil type, generally has frequency characteristics as shown in FIG. This corresponds to a certain high frequency region. It is also assumed that the electrostatic speaker 241 has a frequency characteristic excellent in reproducing high pitched sounds, with a certain high frequency range as a low cutoff frequency, as shown in FIG. 5c. Furthermore, series resistors R, , R2 are connected on both sides of the primary and secondary sides of the step-up transformer 251, but this will not be the same when replaced with an ideal transformer IT as shown in Figure 5f. It is also expressed by an equivalent circuit in which only a resistor corresponding to the above-mentioned (constant) resistance R is inserted on the next side. Then, the (constant) resistance R and the electrostatic speed force 2
By causing an integral action at a certain high frequency fc with the capacitor section 41, the frequency characteristics of the output section consisting of the step-up transformer 251, the resistors R, R2, and the electrostatic speaker 241 are expressed as shown in Fig. 5d. As shown in Figure 2, it is constant up to a certain high frequency and above, for example -
It shall have the characteristics of Beni B/oct. Therefore, in this way, a sound reproduction system in which a single amplifier is shared and the low-mid range reproduction system and the high-pitched sound reproduction system are respectively reproduced exclusively, first of all, in the low-mid range, the same as before. It is reproduced at a sufficient output level necessary to reproduce the sound field in a low-mid sound field, and in a high-pitched sound field, the overall characteristics are as shown in Figure 5e, with a peak at a certain high frequency fc. mountain (top and bottom are old/
Since the characteristic (cut at Mt) can be obtained, no sound pressure is required in the high frequency range as described above, and therefore the output level may be small. The key is to reproduce the music in such a way that it satisfies the need for balance for each range. In other words, by adding an integral action to the bare characteristics of the electrostatic speaker (broken line in the figure) as shown in Figure 5e, which is not accompanied by an integral action, as in the present invention, the treble castle as a whole can be made to have a peak as described above. It depends on its characteristics and what it can do. In this case, by appropriately combining the step-up transformer 251, the resistors R, , R2, and the capacitance of the electrostatic speaker 241 in the high-pitched sound castle, as shown in FIG. It is obvious that it is possible to realize a filter circuit for an electrostatic speaker that has a frequency characteristic of a peak that is cut by .

In addition, in a filter circuit for electrostatic force using such a step-up transformer, the resistance is necessary to bring about an integral action to return a velocity type (or acceleration deformation) signal to an amplitude type signal. For R,, R2, the winding resistance of the step-up transformer may be actively used.In this case, rather than simply using the resistance distributed evenly in the winding, It is more effective to use the desired equivalent resistance R created by winding a resistance wire or a thin wire around a desired part on both sides or in the middle of the secondary side (secondary side).

Furthermore, Fig. 6 shows the velocity type (or acceleration type) in the above.
The output section of the reproduction system operated by the electrostatic speaker 24
This is a specific example of a filter circuit for an electrostatic speaker in which the amplifier 23 is accompanied by an integral action.
An electrostatic speaker 243 is connected in series through the (constant) resistance R at the output section of No. 3, and a choke coil or the like is connected in parallel to the electrostatic speaker 243 from the point where the (constant) resistance R is divided. The inductance L, is connected.

Therefore, according to the filter of such an electrostatic speaker, the (constant) resistance R at the output section of the amplifier and the capacitance of the electrostatic speaker are accompanied by an integral action, so that the velocity (or acceleration) is transmitted to the inside of the amplifier. In addition to its original function of converting the signal that has been used in the form (type) back into an amplitude type signal, it also acts as a low-pass filter by itself, as mentioned above, to remove unnecessary high frequency components.
By using a filter in which an inductance L is inserted at a point where the resistance R is partially divided, the desirable peak in the high frequency range as shown in Fig. 5e can be achieved without any adverse effect on the integral action. Nari (Both upper and lower mother old/
oct) frequency characteristics can be obtained.
Figures 7a and 7b show the above-mentioned concrete application examples. In both cases, in a disc record playback system, when the equalization characteristic (preenphasis) of the disc record is around 2 kHz or higher, the frequency sacrifice (fifth B/oct) is shown. Diagram b
By taking advantage of the fact that the gain has increased so that it has a characteristic of = 2 kHz), we provide a disc record playback device that can be treated as a differential signal in this band, that is, can be operated as a velocity type signal. It is something to do. First, FIG. 7a shows a case where an amplitude (proportional) type cartridge 211 is used;
For the amplitude signal from 11, the equalizer circuit 20 and amplifier 234 equalize only the signal below around 2 kHz and amplify it while keeping the signal above that flat. Here, the electrostatic type speed force 2
On the 45 side, the (constant) resistance R and the capacitance C of the speaker itself cause an integral action in the vicinity of 2kHz or higher, thereby generating a 2kHz signal that is essentially a velocity type signal.
Signals above the vicinity of the Z are converted back to amplitude signals for reproduction, and in this case, of course, signals below the vicinity of the water HZ are reproduced on the electromagnetic speaker 244 side as before. Also, figure b shows the velocity (proportional) type cartridge 2.
12, and such a cartridge 212
The equalizer circuit 201 and the amplifier 235 return only the signal below the water HZ level to an amplitude signal, and the remaining speed signal is amplified as it is, and then the electromagnetic speaker 246 and the electrostatic speaker 247 The following is the same as in the case of figure a.

Although the amplifier has two output terminals in both FIGS. 7a and 7b, it may be configured such that the output terminals are branched from one output terminal. According to such a disc record playback device, the effect of the sound playback system that shares the aforementioned single amplifier and separately reproduces low-mid range and high-temperature range can be achieved by playing back disc records. This is something that can be played out concretely in the system.

In other words, in order to suppress the treble range and make the overall frequency response as flat as possible, an integral action is involved on the treble side. This can be obtained without using any circuits. Furthermore, Figure 8 shows a specific application example adopted in a multi-channel playback system. In this case, channel C, which is responsible for the low-mid range,
The outputs of H and H are supplied as they are to the electromagnetic speaker 24a and reproduced with predetermined band characteristics in the same way as the secondary speakers, and channel CH2, which is mainly in charge of high temperature control (however, if necessary, differential processing is applied to adjust the speed) Operate as a shape signal.

) is passed through an appropriate filter circuit as mentioned above, including a (constant) resistance Ro (but not an internal one, but an external one) to give it a frequency characteristic as shown in Fig. 5d. The signal is supplied to the electrostatic loudspeaker 24M with an integral action, and the signal is returned to an amplitude type, and at the same time, the signal is reproduced with a predetermined band characteristic.
According to such a multi-channel reproduction system, as shown in FIG. 9, as a result of weighting the band characteristics of each channel CH, CH2, the overall band characteristics as a whole can be made as flat as possible, and especially In the high frequency range, the same effect as that of the sound reproducing apparatus shown in FIG. 2 described above can be achieved.

Figure 10 shows a specific example of the application of the same machine to a magnetic tape playback system such as a tape recorder. Electromagnetic speaker 24c as is
Channel CH2a (which is mainly in charge of high-pitched sound)
However, if necessary, differential processing is performed and the signal is used as a speed-type signal.

) is the (constant) resistance R. , (however, the filter circuit is not internally connected, but is externally attached) as described above, and the frequency characteristic as shown in FIG. The signal is supplied to the electrostatic speaker 24d to be returned to an amplitude signal, and at the same time, it is reproduced with a predetermined band characteristic. According to such a magnetic tape playback system, as shown in FIG. 9 described above, the band characteristics of each channel CH, CH2 are weighted, so that the overall band characteristic as a whole can be made as flat as possible. At the same time, the same effect as that of the above-mentioned sound reproducing apparatus shown in FIG. 2 can be achieved especially in high-pitched music.

FIG. 11 shows a basic example of a sound reproducing device in which the signal transmission system is operated in the acceleration type, and the audio signal from the cartridge 211 is given as an amplitude type signal when the cartridge is of an electrostatic type, for example. is a two-stage differentiation circuit 21
1, 222, or if the cartridge is of an electromagnetic type and is given as a velocity signal, the signal transmission system is In other words, the acceleration type signal is obtained by performing one-time differentiation processing on the amplitude component as described above, and then further differentiating the velocity type signal by the time component. As a result, it is obtained by performing differentiation twice on the amplitude component, so it is much more sensitive to time component-related signals (distorted waves and noise components generated in the amplifier, etc.) than the velocity-type signal described above. This improves the S/N ratio and distortion rate of the entire system very significantly, and also expands the dynamic range of the amplifier itself and increases its effective utilization rate. It becomes possible.

In addition, the signal that has been operated as an acceleration type signal in this way is subjected to first integration processing using the time component in the integrator 27 at the output section outside the amplifier, and as a result is converted back to a velocity type signal, and is subsequently converted into a velocity type signal. (constant) resistance (R
) and the capacitance component c in the electrostatic speaker 242 are accompanied by a second integration action with respect to the time component, and as a result, the signal is finally returned to an amplitude type signal and is transmitted to the electrostatic speaker 242.
This is reproduced as an acoustic output, and the effect is approximately equal to or greater than that of the output section shown in FIG. 2, which is accompanied by a single integral action.

It goes without saying that operating the signal transmission system in an accelerated manner as described above can be implemented as necessary for each of the above-mentioned specific application examples. Therefore, as detailed above, according to the present invention, the low-mid range is directly reproduced by the electromagnetic speaker, and the treble range is subjected to differential processing and then integrated at the output section including the electrostatic speaker. By playing along with
It becomes possible to provide a sound reproduction device that can reproduce sound with a balance suitable for each range.

[Brief explanation of the drawing]

FIG. 1 is a circuit configuration diagram showing a typical conventional sound reproduction device, FIG. 2 is a circuit diagram showing a basic example of the audio reproduction device according to the present invention, and FIG. 3 is a circuit diagram showing another basic example. The configuration diagram, Figure 4, is a book based on the basic example of Figures 2 or 3, in which a single amplifier is shared and the low-mid range reproduction system and the high-frequency range reproduction system are respectively reproduced exclusively. Circuit configuration diagram showing an embodiment of the sound reproduction device according to the invention, FIG. 5a-
f is a frequency characteristic diagram of each part and an equivalent circuit diagram on the treble reproduction side to explain the action of FIG. 7, FIG. 6 is a diagram showing another specific example of the electrostatic speaker filter circuit used in the present invention, 7a and 7b are circuit configuration diagrams showing a disc record playback system as a specific application example of the embodiment shown in FIG. 4, and FIG. 8 is a circuit configuration diagram showing a multi-channel playback system as another specific application example. 9 is a band characteristic diagram for explaining the action of FIG. 8, FIG. 10 is a circuit configuration diagram showing a magnetic tape reproducing system as another specific application example, and FIG. 11 is a diagram of the same according to the present invention. FIG. 2 is a circuit configuration diagram showing a sound reproduction device operated in an acceleration mode as another basic example according to the present invention. 21... Cartridge, 231... Amplifier, 241... Electrostatic speaker, 251...
...Step-up transformer, 26...Electromagnetic speaker. Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 8 Figure 7 Figure 9 Figure 10 Figure 11

Claims (1)

[Claims] 1. The input signal is configured to be amplified with a predetermined differential process above fc so that the input signal has a flat characteristic up to a predetermined high frequency fc and a characteristic that increases at a predetermined slope above fc. an electromagnetic speaker for reproducing low and midrange frequencies, which is directly connected to the output end of the amplifier and whose fc is set to a high cutoff frequency; and a filter circuit connected to the output end of the amplifier. and an electrostatic speaker for high frequency reproduction in which the fc is set to a low cutoff frequency, and the resistance component of the filter circuit and the capacitance component of the electrostatic speaker exceed the fc. A sound reproducing device characterized in that it is configured to substantially obtain a mountain-like characteristic with the peak at the fc in the high frequency range by performing an integral process such that fc falls at a predetermined slope.