JPS5990897A - Audio apparatus - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Industrial applications This invention relates to an audio device.

Conventional configurations and problems There have been many proposals regarding reverberation adding devices. The basic idea is that, as shown in Figure 1, the output of amplifier 1 is fed back to the input of amplifier 1 at an appropriate level via delay circuit 2 with a predetermined delay time, and the echo time pattern shown in Figure 2 is obtained. be.

A plurality of these circuits are combined to perform processing such as making the synthesis level variable, and in either case, the variable amount can be changed according to the user's preference. However, the user has no way of knowing which state is closest to the recording state or the acoustic state at the time of recording. Also, the more delay circuits there are, the more finely the time can be controlled, and the more reverberation can be obtained that is similar to that of a good recording, but the more control items the user has to control, the more complicated it becomes to control each level of each delay time. The reality is that I don't feel like using it.

OBJECTS OF THE INVENTION It is an object of the present invention to solve the above-mentioned problems and to provide an audio device that can easily obtain reverberations close to those in a recording state.

According to the present invention, at least one of the reverberation time, frequency characteristics, and echo time pattern of a listening room such as a recording hall and a playback listening room is controlled by a control means. This makes it possible to receive reverberations that are closer to those of recording.

In particular, this can be easily realized by using a personal computer (hereinafter referred to as a personal computer), which is becoming popular in ordinary homes, which has arithmetic functions and sequence functions as a control means, and it is also possible to create new reverberant sounds and reflected sounds.

DESCRIPTION OF THE EMBODIMENTS An embodiment of the present invention is shown in FIGS. 3 to 10. First, Figure 3 is a cross-sectional view of the large hall 3, in which the direct sound 10 of the sound wave from the sound source 5, which is admired above the stage 4, and the primary reflection 14.
and the path of the secondary reflection 15. The reverberation pattern at the listening point 6 is as shown in Figure 5 (al). In the playback listening room 7, the reverberation pattern is as shown in Figure 4. Secondary reflection 12
and is propagated to the listening point 9. FIG. 5 (bl shows the reverberation pattern in this listening room).

FIG. 6 shows an embodiment of the configuration according to the present invention, in which the signal from the audio input 26 is converted into a digital signal by an A/D (analogous digital) converter 27,
The signals are sequentially delayed by a shift register group 28 (FIG. 8), and each delayed output obtains a reverberant sound by a reverberation 7<turn generation circuit 30. A microcomputer (hereinafter referred to as a microcomputer) 31 controls a reverberation pattern generation circuit 30 under the control of a computer 39 . The interface 38 transfers control output signals from the personal computer 39 to the microcomputer 31 and data from the microcomputer 24 to the personal computer 39. As shown in FIG. 8, the reverberation pattern generation circuit 30 converts the output of the shift register group 28 into an analog quantity with a D/A (digital-to-analog) converter 48, and after reaching a predetermined level with a gain adjustment circuit 49, a multiplexer 50 The predetermined delayed output is added or subtracted by the adder 51.

Further, the output of each gain adjustment circuit 49 is added with a predetermined delayed output by the feedback circuit 32, and fed back to the input 26, where it is delayed and combined again, and the speaker 19 (8) is driven by the power amplifier 18 via the switch S□.

Also, when measuring the reverberation characteristics of the playback listening room 7, switch the The S unit is turned to the A side, an impulse signal is applied from the input 17, and the sound from the speaker 19 is collected together with the reflected sound by the microphone 2o at the listening point 9, amplified by the amplifier 22, and then sent to the comparator 23. By software and D/A conversion of the adder 25 and the microcomputer 24, the level and time of the reverberant sound are transferred to the personal computer 39 via the interface 38 and stored therein. The clock signal 29 sets the unit time of the shift register. On the other hand, a keyboard 35 is connected to the input of the personal computer 390, and is controlled by the user's command. When the user inputs the coordinates of the shape of the hall, the personal computer 39 calculates a reverberation pattern as shown in FIG. Similarly, data can be input from a tape recorder 33, floppy disk 34, etc., and if a disk on which reverberation time characteristics of famous halls are recorded in advance is prepared, it can be immediately input into the computer 39. The control program can be created by the user, and the software can be purchased and inputted from a 70 Soppy disk, just like other personal computers.

The personal computer 39 operates according to the control program based on the data obtained as described above, and an example thereof is shown below.

First, the reverberation characteristics obtained by setting the switch S□ to A fullll and inputting an impulse are stored in the personal computer 39 in terms of time and level as shown in FIG.
The reverberation characteristics of a famous large pole from B-Disc are shown in the fifth section.
Figure (al) is entered into the computer 39 in the form of Figure 5 (al).
The reverberation characteristics are compared with that of the A1, and the multiplexer is driven to reduce the difference between the reverberation characteristics and the reverberant sound. In other words, the fat in Figure 5 between the sound source and the microbon during recording
In order to obtain hall reverberation characteristics, select each time output of a delay circuit such as a shift register, adjust each level by division (or subtraction) based on K in Figure 5 (a), and calculate each delay time output. are added to create reverberant sound. On the other hand, in the data obtained by actually measuring the reverberation characteristics in the playback listening room 7 (Figure 5 (b)) or inputting the shape of the listening room and the coordinates of the sound source and listening point, reverberant sounds that are not in the reverberation characteristics of the recording and playback hall (Figure 5 Cal) In order to reduce unnecessary reverberation in the playback listening room, the phase of the delay circuit output corresponding to each delay time is reversed and the levels are matched and added (or the same can be done by subtracting without changing the phase). After erasing as shown in Figure 5 tc+, adding the reverberation sound created in Figure 5 (bl) and creating Figure 5 f (
Listening room 7 that reproduces the reverberation sound from pure recording as shown in 1)
You can listen to it at listening points.

The shift register group 28 has flip-flops 44 connected to each hit signal of the digital signal as shown in FIG. M
It consists of digital signals from SB to LSB. In this FIG. 7, 40 to 42 are digital input signals, and 45
is a first-order delay output, 46 is a second-order delay output, and 47 is an n-order delay output/output. However, regarding this delay, it is also possible to use a so-called RAM instead of a shift register, or to configure it with a BBD element or CCD element with the Analog signal intact.In either case, each delay output is selected by the digital control signal of the personal computer 39. Take it out and put it on the computer 39
A similar result can be obtained by controlling each level according to the calculation result of . Furthermore, if each delayed signal in FIG. 7 is fed back to the input as shown in FIG. 8, an even longer delay time can be obtained with fewer delay elements. Feedback level and return time in this case (
This can be realized by changing the connection of the feedback loop using the multiplexer 50 according to the calculation result of the control Mohaso controller (from which delay time to which feedback is to be made).

In addition, the sound path table calculated by the computer 39 is displayed on a two-dimensional display device such as a cathode ray tube display 37 or an XY recorder 36 to display the actual state of reflection in the hall to the user, which is useful for elucidating and improving sound quality. be able to. This display can be done using two-dimensional cross-sectional views as shown in Figures 3 and 4, or three-dimensional cross-sectional views of the sound path as shown by the broken lines in Figure 9.
In addition to displaying in dimensional figures, the level and time of each reflected sound can also be displayed graphically using echo time patterns as shown in Figure 5 (al to fdl).

In the above explanation, the frequency characteristics related to each delay were explained as being flat, but in an actual room, the reverberation time depends on the sound absorption frequency characteristics of the materials such as the interior walls, 9 floors, and the ceiling. It has a different level (reflectance) depending on the frequency and is not uniform over all frequencies. Therefore, when strictly correcting not only the delay time but also its frequency level characteristics, a frequency characteristic compensation circuit is installed at the output of each delay circuit, and the frequency is corrected based on the sound absorption coefficient information of walls, ceilings, etc. input by the user. If you want to measure the reverberation frequency characteristics of the listening room by setting the switch S□ to A 1llll, time-division the microphone output signal and subjecting the data to frequency analysis such as F, F, and T for each delay time. When recording, reverberation characteristics, including frequency characteristics, can be controlled, making it possible to compensate for most of the differences in room characteristics between the recording room and playback room.

Furthermore, even when there are multiple sound sources 5.8 for recording and playback, an example of its application is to analyze the data for each sound source in the same manner and use multiple delay playback systems to control each playback system as described above. Of course.

By configuring the system surrounded by the broken line in Figure 6 in this way, it is possible to freely control reverberation sound based on the program on the computer 39, and it is possible to eliminate a large difference in reverberation time between recording and playback. Even in such cases, reverberation can be corrected.

Furthermore, if the frequency characteristics are also controlled, the reverberant frequency characteristics of the playback listening room can be corrected, and construction work such as changing the wall material of the listening room, which was required in the past, is no longer necessary, so the utility value is extremely high. be. The personal computer 39 can also be a dedicated computer such as an audio computer that also controls other audio devices; in any case, it has a calculation control function that calculates reverberation patterns and drives peripheral devices according to a program. It's fine as long as it's something. Further, FIG. 10 is a flowchart showing the following functions.

Effects of the Invention Conventionally, the audio equipment of the present invention requires complicated information, which requires a great deal of effort to organize and analyze, and the difficulty of changing the reverberation characteristics of the listening room, such as changing the wall material of the room. By solving the problems involved, users can easily obtain reverberation close to the recording state, and users can create any desired reverberation sound while referring to quantitative information such as shapes and reverberation time. It can provide a number of advantages, such as the ability to make a studio-recorded source the sound of any famous hall by simply operating the keys.

[Brief explanation of the drawing]

Figure 1 is a diagram of a conventional analog delay circuit, Figure 2 is a diagram of its reverberation pattern, Figure 3 is a schematic sectional view of a recording hall to which an embodiment of the present invention is applied, and Figure 4 is a listening room (playback room). ), FIG. 5 is a reverberation pattern diagram, FIG. 6 is a system f/cl diagram of an embodiment of the present invention, FIG. 7 is a digital delay circuit diagram configuring a shift register, and FIG. 8 is a diagram of a digital delay circuit constituting a shift register. 9 is a perspective view of the recording hall, and FIG. 10 is a flowchart of the system program of the computer. 3...Recording hall, 4...Stage, 5...Sound source, 7...Reproduction listening room, 8...Speaker, 6.9...
・Listening point, 10...Direct sound, 11.12,13,14
．． 15°16...Reflected sound, 17...Pulse input, 1
8.22...Add 11QfH, 20...Microphone, 23...Comparator, 25.51...Add"Jk
, 24 * 31...Microcomputer, 26...Audio input, 27...Analog-digital converter, 29...
・Clock signal, 28...Shift register group, 32・
...Feedback circuit, 33...Magnetic tape, 34...Floppy disk, 35...Keyboard, 36...X
Y recorder, 37... CRT display, 38
...Common interface, 39...Personal computer (2) Figure 1 Figure 2 Figure 3 Figure 4 Figure 9 Figure 10

Claims (1)

[Scope of Claims] (1) An audio device main body, and a control means attached to the audio equipment body for controlling at least one of the reverberation time, the frequency characteristic of the reverberation time, and the echo time pattern in the listening room. Audio equipment with. (2) The audio device according to claim 1, wherein the control means includes a device for measuring the echo time pattern and reverberation time frequency characteristics of a listening room or recording hall, and a device for capturing and storing the measured data. (3) The control means inputs information representing the drawing of the listening room in coordinates and information representing the sound source point and listening point in the listening room in coordinates, and controls each sound path of the direct sound and each of the n-th reflected sounds. The audio device according to claim 1, which calculates the length and displays and stores the result. (4) The control means has a storage/reproduction device such as a disk or tape on which acoustic information such as the reverberation time and echo time pattern of the recording hall and coordinate information of the three-dimensional structure of the hall are recorded. The audio device described in item 1). (51) The control means compares the reverberation characteristics including the echo time pattern between the sound source point and the listening point in the recording hall with the reverberation characteristics between the sound source point and the listening point in the playback listening room, and adjusts the reverberation so that the difference is reduced. The audio device according to claim (1), which has a function of calculating addition, subtraction, time difference, etc. of reverberant sound at each frequency or the entire audible band in order to control the sound addition circuit. (6) @ The audio device according to claim (1), wherein the control means has a function of manually inputting an arbitrary echo time l<turn or reverberation time characteristic using keys. (7) The audio device main body and the control means Claims (1) and (2) include software that supports multiple sound sources during recording and playback;
The audio device according to item (3), item (4), or item (5). (8) Claims (1) and (2) above, wherein the control means displays various information or calculation results two-dimensionally, three-dimensionally, or chronologically on a display device such as a cathode ray tube or printer. , Sections (3) and (4). The audio device according to item (5), item (6), or item (7). (9) Claims (1) and (2) wherein the control means includes a reverberation characteristic control device and a personal computer and can be connected through a common interface.
), (3), (4), (5), (6)
Section. The audio device according to item (7) or item (8).