close

Вход

Забыли?

вход по аккаунту

JPH04320199

код для вставкиСкачать
Patent Translate
Powered by EPO and Google
Notice
This translation is machine-generated. It cannot be guaranteed that it is intelligible, accurate,
complete, reliable or fit for specific purposes. Critical decisions, such as commercially relevant or
financial decisions, should not be based on machine-translation output.
DESCRIPTION JPH04320199
[0001]
BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a
sound reproducing apparatus for improving room acoustical characteristics.
[0002]
2. Description of the Related Art In recent years, as a method of correcting and flattening room
acoustic characteristics lacking in bass and treble, an acoustic reproduction apparatus using an
amplitude correction circuit that changes the amplitude characteristic of an acoustic signal is
actively used. However, the current situation is that the amplitude correction means is not
considered very much. A conventional sound reproduction apparatus will be described below.
FIG. 8 is a block diagram showing an example of a conventional sound reproducing apparatus. 1
is an acoustic signal source such as a tuner, a tape deck, a compact disk player, 2 is an amplitude
correction circuit, 3 is a power amplifier, and 4 is a speaker.
[0003]
FIG. 9 is a circuit diagram of an amplitude correction circuit 2 composed of resistors 5 and 6 and
capacitors 7 and 8, and FIG. 10 is an amplitude frequency characteristic diagram of the
amplitude correction circuit 2. As shown in FIG.
[0004]
08-05-2019
1
The operation of the sound reproducing apparatus configured as described above will be
described below.
First, the signal sent from the acoustic signal source 1 is amplified by the power amplifier 3 with
the amplitude correction circuit 2 shown in FIG. And reproduced by the speaker 4. As a result, it
is possible to obtain room acoustic characteristics in which low and high frequencies are
insufficient only with the sound reproduction device without the amplitude correction circuit 2.
[0005]
However, in the above-described conventional configuration, the characteristics of the amplitude
correction circuit 2 limit the amount of correction, and if sufficient correction is made in the low
band and high band, 500 Hz is not necessary. As shown in FIG. 11, there is a problem that the
room acoustic characteristics reproduced are not flat as shown in FIG.
[0006]
The present invention solves the above-mentioned conventional problems, and provides an audio
reproduction apparatus which emphasizes only the low band and high band of an audio signal
and realizes an amplitude correction which does not affect the middle band. It is the purpose.
[0007]
SUMMARY OF THE INVENTION In order to solve the problem, the sound reproducing apparatus
according to the present invention has a second high-pass filter with a Q of 3.0 or more, and a Q
of 3.0 or more. Comprising an amplitude correction circuit configured by connecting in series a
second-order low-pass filter set to a power amplifier for amplifying the output of the amplitude
correction circuit, and a speaker for reproducing the output of the power amplifier It is.
[0008]
[Operation] With this configuration, it becomes possible to perform amplitude correction that
emphasizes only the low band and high band of the sound signal without affecting the middle
band, and to realize flat room acoustic characteristics.
[0009]
08-05-2019
2
Embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a block diagram showing the configuration of a sound reproduction apparatus according
to an embodiment of the present invention.
In FIG. 1, 9 is an acoustic signal source such as a tuner, a tape deck or a compact disc player, 10
is a secondary high pass filter, 11 is a secondary low pass filter, 12 is a power amplifier, and 13
is a speaker.
[0010]
The operation of the sound reproducing apparatus configured as described above will be
described below.
First, the output of the acoustic signal source 9 is input to the secondary high pass filter 10.
As shown in FIG. 2, the second-order high-pass filter 10 is composed of resistors 14 and 15,
capacitors 16 and 17, and one amplifier 18, and the input / output transfer function is
represented by the equation .
[0011]
[Equation 1]
[0012]
The low-pass cutoff frequency of the second-order high-pass filter 10 and Q indicating the
sharpness of resonance are expressed by equations (2) and (3).
[0013]
[Equation 2]
08-05-2019
3
[0014]
[Equation 3]
[0015]
Here, the resistance 14 is 1.8 KΩ, the resistance 15 is 68 kΩ, the capacitor 16 is 0.27 μF, and
the capacitor 17 is 0.27 μF so that Q is 3.0 and the low cutoff frequency is 50 Hz. When each
constant is set, as shown in FIG. 3, it is possible to give a peak to the amplitude frequency
characteristic in the vicinity of the low cutoff frequency, and to secure a level difference of about
10 dB with the midrange of 500 Hz or more.
In other words, the amplitude frequency characteristic of the second-order high pass filter 10
emphasizes the low range.
[0016]
Next, the output of the secondary high pass filter 10 is input to the secondary low pass filter 11.
As shown in FIG. 4, the second-order low pass filter 11 is composed of resistors 19 and 20,
capacitors 21 and 22, and one amplifier 23, and the input / output transfer function is expressed
by equation (4).
[0017]
[Equation 4]
[0018]
The high-frequency cutoff frequency of this second-order low-pass filter 10 and Q indicating the
sharpness of resonance are expressed by equations (5) and (6).
[0019]
[Equation 5]
08-05-2019
4
[0020]
[Equation 6]
[0021]
Here, the resistance 19 is 1.8 k.OMEGA., The resistance 20 is 1.8 k.OMEGA., The capacitor 21 is
0.027 .mu.F, and the capacitor 22 is 0.1 .mu.F so that Q is 3.0 and the high cutoff frequency is
15 KHz. When each constant is set to μF, as shown in FIG. 5, it is possible to give a peak to the
amplitude frequency characteristic in the vicinity of the high frequency cutoff frequency, and to
secure a level difference of about 10 dB from the midrange of 5 KHz or less.
In other words, the amplitude frequency characteristic of the second-order low pass filter 11 is
such that the high region is emphasized.
The output passing through the secondary low pass filter 11 has an amplitude frequency
characteristic obtained by combining the amplitude frequency characteristic of the secondary
high pass filter 10 as shown in FIG.
This is because the output impedance of the secondary high pass filter 10 is lowered by the
amplifier 18 and does not become a load on the secondary low pass filter 11 in the subsequent
stage, and does not affect the amplitude frequency characteristic.
When this output is applied to the power amplifier 12 and reproduced by the speaker 13, an
output in which the room acoustic characteristic in which the low band and the high band are
insufficient is corrected is obtained, and a flat room acoustic characteristic as shown in FIG. 7 is
obtained.
[0022]
As described above, according to the present embodiment, the secondary high pass filter 10 with
Q set to 3.0 and the secondary low pass filter 11 with Q set to 3.0 are connected in series. By
providing the amplitude correction circuit configured as described above, it is possible to
perform correction that emphasizes only the low band and high band of the sound signal and
does not affect the middle band, as compared with the sound reproduction device constituted by
08-05-2019
5
the conventional amplitude correction circuit. This can be achieved to achieve flat room
acoustics.
[0023]
In the above embodiment, active filters are used for the second high-pass filter 10 and the
second low-pass filter 11, but the second high-pass filter 10 and the second low-pass filter 11 are
You may comprise by a passive filter.
In this case, the circuit configuration is simplified since no amplifier is required.
Further, it is needless to say that it is not necessary to set Q to 3.0 for both the low band and
high band with respect to the amplitude amount to be corrected, and it may be set to 3.0 or
more.
Furthermore, although the secondary low pass filter 11 is connected in series behind the
secondary high pass filter 10 in the above embodiment, the secondary high pass filter 10 is
connected in series behind the secondary low pass filter 11 You may make it the structure.
[0024]
As described above, according to the present invention, the second high-pass filter for
emphasizing the low band of the amplitude characteristic of the acoustic signal and the second
low-pass filter for emphasizing the high band are provided. An amplitude correction circuit
emphasizes only the low and high frequencies of the acoustic signal to form an amplitude
characteristic that does not affect the middle frequency, and obtain an output in which the room
acoustic characteristics lacking the low and high frequencies are corrected. It is possible to
realize an excellent sound reproducing device that can
[0025]
Brief description of the drawings
[0026]
1 is a block diagram of a sound reproduction apparatus according to an embodiment of the
08-05-2019
6
present invention
[0027]
Fig. 2 Circuit diagram of secondary high-pass filter Fig. 3 Amplitude frequency characteristic of
secondary high-pass filter Fig. 4 Circuit diagram of secondary low-pass filter Fig. 5 Amplitude
frequency of secondary low-pass filter Characteristic diagram Fig. 6 Amplitude frequency
characteristic diagram when the second-order high-pass filter and second-order low-pass filter
are connected in series Fig. 7 A room acoustic characteristic diagram by the sound reproduction
apparatus in one embodiment of the present invention
[0028]
8 is a block diagram of the conventional sound reproduction apparatus FIG. 9 is a circuit diagram
of the same amplitude correction circuit
[0029]
Fig. 10 Amplitude-frequency characteristic diagram of the same amplitude correction circuit Fig.
11 Description of the room acoustic characteristic diagram code by the same acoustic
reproduction device
[0030]
9 acoustic signal source 10 second order high pass filter 11 second order low pass filter 12
power amplifier 13 speaker 14, 15, 19, 20 resistor 16, 17, 21, 22 capacitor 18, 23 amplifier
08-05-2019
7
1/--страниц
Пожаловаться на содержимое документа