JPH02240696A - Musical tone synthesizer - Google Patents

Abstract

PURPOSE:To produce the sounds of an electric type guitar by adding the waveform data stored in memory positions different from each other in a delay part and the output data of a bridge part. CONSTITUTION:The bridge part 12 which takes the waveform data W 1, W 2 out of the memory positions different from each other of the delay part 11 and subjects the waveform W 2 which is later in time of the taken-out waveform data to a processing corresponding to the influence of a bridge is provided. An adder 13 which adds the waveform data W 1 which is earlier in time and the output data of the bridge part 12 is provided. The sounds of the electric-type guitar outputted by using a pickup in the position apart from the bridge are produced in this way.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a musical tone synthesis device that uses a digital electronic circuit to implement an algorithm that approximates the sound generation mechanism of a musical instrument.

Conventional Technology Various sound source systems for electronic keyboards and synthesizers have been developed over the years, and with the remarkable progress of digital technology in recent years, many high-quality musical tone synthesis devices based on the above-mentioned sound source systems have been developed. . Among them, sound source methods have been proposed that analyze the sound generation mechanism of acoustic instruments and approximate this using various calculations.

(For example, the document “Extensions of the Capra Strong Black Toast String Algorithm J
(Extensions of the Ka
rplus-5strong Plucked-3tri
ng Algorthm Author: Davld^,
Jaffe and Jullus O, Sm1th
Source: computerMuslc Journal
1, yo17.2. Summer f983. p
(age 58-B9)) Since the sound source method is introduced in a form similar to hardware, it is easy to implement it as a musical tone synthesis device using digital electronic circuits. Referring to the drawings below,
A musical tone synthesis device based on the above-mentioned sound source method will be explained.

FIG. 5 shows a block diagram of a conventional musical tone synthesis device.

In FIG. 5, 51 is a delay section that temporarily stores waveform data, 52 is a feedback section that processes the waveform data output from the delay section 51, and outputs the processing result as feedback waveform data, and 53 is a section that processes the waveform data output from the delay section 51. This is an input control section that selects input feedback waveform data and externally input drive waveform data, and outputs the selection result to the delay section 51 as input waveform data.

FIG. 6 shows a block diagram of a conventional musical tone synthesizer, and differs from FIG. 5 only in the configuration of the input control section. That is, the input control section 63 is configured to add the feedback waveform data input from the feedback section 52 and the drive waveform data input from the outside, and input the addition result to the delay section 51 as input waveform data. . Other blocks are the same as those in FIG.

FIG. 7 shows a circuit diagram of the delay section 51. In FIG. 7, 71 shifts the waveform data X, ~Xn temporarily stored therein one step at a time in the output direction (right direction) based on the system clock SCK (corresponding to the sampling period Ts), and also performs the shift operation. This is a shift register that inputs input waveform data to the input end (left end) side and outputs output waveform data from the output end (right end) side in synchronization with . Note that the same operation can be performed by using a memory that can temporarily store a plurality of data and an address circuit that manages addresses of the memory instead of the shift register.

FIG. 8 shows a circuit diagram of the feedback section 52. In FIG. 8, 81 is a delay device that delays the input waveform data by the sampling period Ts and outputs it to the multiplier 82. 82 is a delay device that delays the input waveform data by a sampling period Ts and outputs it to the multiplier 82. A multiplier 83 performs multiplication, a multiplier 83 multiplies the input waveform data by a preset value of 1/2, and 84 performs addition of the waveform data output from the multiplier 82 and the multiplier 83. It is an adder.

The above circuit is generally known as a first-order low-pass filter.

FIG. 9(A) shows a circuit diagram of the input control section 53. In FIG. 9(A), 91 selects drive waveform data input from the outside when a sound generation instruction signal is input from the outside, and selects a feedback waveform data input from the feedback section 52 when no generation instruction signal is input from the outside. This is a selector that selects data.

FIG. 9(B) shows a circuit diagram of the input control section 63. In FIG. 9(B), an adder 92 adds drive waveform data input from the outside and feedback waveform data input from the feedback section 52, and inputs the addition result to the delay section 51 as input waveform data. It is.

FIGS. 10 to 12 are state diagrams showing the form of sound produced by the string.

Here, the differences in the pronunciation forms shown in FIGS. 10 to 12 will be explained.

First, FIG. 10 is a state diagram showing a simplified form of sound production of an acoustic guitar, and is a model of a conventional musical tone synthesis device. AC by Natsuto and Bridge
A driving waveform is applied to the midpoint B of the strings between them. The drive waveform propagates in the direction of point A and in the direction of point 0, respectively.
It is reflected at point 0 and returns to point B again. The above operations are repeated, and as a result, the string vibrates. The vibrations of the strings are then transmitted to the resonator at the bridge, where they can be heard as amplified sound.

For the sake of simplicity, let's assume that the string is fixed under exactly the same conditions at points A and 0. Since point B is the midpoint between AC, one direction (for example, point B → point C → point B → point A →Point B)
It is safe to consider only the propagation of . Furthermore, if we consider the reflection at point A or point 0 to be an inversion operation due to the fixed end and a first-order low-pass filter to the effect of harmonic components leaking to the nut or bridge, we can obtain the string sound form shown in Figure 10. A musical tone synthesizer approximated by a digital circuit can be shown in FIGS. 5 and 6.

Next, FIG. 11 is a simplified state diagram of the sound generation mode of an electric type guitar in which a pickup is installed at a position slightly away from the bridge, and string signals are electrically extracted by this pickup. The basic movement is the first
This is the same as Figure 0, but the difference is the position from which the output waveform is taken out, and the output waveform is obtained from a position a distance l away from the bridge.

Finally, Figure 12 is a special example of Figure 11, in which a pickup is installed a little away from the bridge, and this pickup electrically extracts the vibrations of the strings. FIG. 2 is a simplified state diagram of a sound generation form in which sound is input to a pickup through the body of a guitar. The basic movement is the first
This is the same as FIG. 0 and FIG. 11, but the difference is the position from which the output waveform is taken out, as shown in FIG. 11, and the output waveform is obtained from a position located a distance 1 from the bridge.

The operation of the musical tone synthesis apparatus constructed as described above will be explained below with reference to FIGS. 5 to 9.

First, in FIG. 5, drive waveform data and a sound generation instruction signal are inputted from the outside to the human control section 53 in order to perform a sound generation operation. Also, at this time, the shift register 71 of the delay section 51
The waveform data Xn stored at the right end of FIG. 7 is output as output waveform data, processed by the feedback section 52, and then inputted to the input control section 53 as feedback waveform data. Since the sound generation instruction signal is input to the input control section 53, the selector 91 (FIG. 9) selects the drive waveform data. That is, the driving waveform data is input as input waveform data to the left end of the shift register 71 (FIG. 7) of the delay section 51. In the shift register 71 (FIG. 7) of the delay section 51, the waveform data stored therein is shifted one stage to the left in response to the output of X and the input of the input waveform data. The above operation is performed every system clock (corresponding to the sampling period Ts). That is, n pieces of waveform data (corresponding to the word length of the shift register 71 of the delay section 51) propagate through a loop system composed of the delay section 51, the feedback section 52, and the input control section 53, and the output waveform data will be output to the outside.

Next, the switching of the selection operation of the selector 91 of the input control section 53 will be described. The selector 91 selects the drive waveform data when the sound generation instruction signal is input, and selects the feedback waveform data when the sound generation instruction signal is not input. drive waveform data is input to the loop system,
Thereafter, when the sound generation instruction signal is no longer input, the input of the drive waveform is prohibited, and the waveform data is permanently looped within the loop system consisting of the delay section 51, feedback section 52, and input control section 53. Become.

Finally, the feedback section 52 will be explained.

1 shown in FIG. 8 as an example of the circuit of the feedback section 52.
The following low-pass filter can be considered. This low-pass filter is realized by simplifying the two effects of the nut and bridge in one circuit in FIG. 10, which represents the sound generation state of strings, which is a model of a conventional musical tone synthesizer. Simply put, the effects of nuts and bridges are reversal action due to their fixed ends and absorption of harmonic components of vibration.

Therefore, when considering the sum of the effects of both the nut and bridge, the reversal action is canceled out, and only the absorption of the harmonic components of vibration remains.
As described above, this can be realized using a first-order low-pass filter.

FIG. 6 shows a musical tone synthesizing device realized by a method different from the musical tone synthesizing device shown in FIG. The only difference from FIG. 5 is the input control section. The input control section 63 in FIG. 6 includes an adder 82 as shown in FIG. 9(B). Adder 9
2, the operation at the start of sound generation changes, resulting in different output waveform data. In the musical tone synthesizer shown in FIG. 5, only the drive waveform data is input to the delay section 51 at the start of sound generation.
In the musical tone synthesis apparatus shown in FIG. 6, drive waveform data and waveform data of a portion of a previously generated musical tone are input to the delay unit 51 at the start of sound generation. If the previously produced musical tone is sufficiently attenuated by the feed pack section 52 before starting to produce it, the operation of the musical tone synthesizer shown in FIG. 5 and the operation of the musical tone synthesizer shown in FIG. There is no difference, but there is a difference if the sound is started when the previously sounded musical tone remains above the audible level. Therefore, when we analyze the vibration state of the strings on an actual acoustic guitar when the sound starts, we find that when you pluck the strings with the drumstick or fingers, the vibrations of the remaining strings are first damped by the drumstick or fingers. I'm letting you do it. Considering this, it seems that the operation of the musical tone synthesizer shown in FIG. 5 is closer to the operation of an actual acoustic guitar. However, an actual acoustic guitar has a resonator, and this resonator allows the sound to remain even when you pluck the strings with the guitar or with your fingers. Considering this fact, it seems that the operation of the musical tone synthesizer shown in FIG. 6 is closer to the operation of an actual acoustic guitar.

From the above explanation of the operation, it can be seen that the string sound generation operation shown in FIG. 10 can be realized by the musical tone synthesizer shown in FIG. 5 or 6.

Problems to be Solved by the Invention However, with the conventional configuration as described above, the sound of a type of guitar (electric type guitar) that uses a pickup to extract an output waveform at a point far from the bridge as shown in Figure 11 cannot be reproduced. The problem was that it was not possible to produce

SUMMARY OF THE INVENTION In view of the above problems, the present invention provides a musical tone synthesis device that can produce electric guitar sounds that are output using a pickup at a position away from the bridge.

Means for Solving the Problems To achieve this object, the musical tone synthesis device of the present invention collects waveform data (W1
, W2) and performs processing corresponding to the influence of the bridge on temporally subsequent waveform data (W2) among the extracted waveform data; W1) and an adder that adds the output data of the bridge section.

Effects With the above configuration, the delay section can be set at a position (B) where the left and right ends output the drive waveform, and where the storage position from which the waveform data W1 and W2 are taken out is different from the position where the drive waveform is output, for example, a position closer to the bridge. Assuming that the string is as shown in (D), the waveform data WL is a traveling wave going from the position (B) where the drive waveform is output to the bridge position (C).The position where the drive waveform is output from the bridge position (C) is the waveform data WL. (B)
The reflected wave directed toward the waveform data W2 is used as the output data of the bridge section that processes the waveform data W2, and the waveform taken out by the pickup is a waveform that is a mixture of the traveling wave and the reflected wave, so it is different from the waveform data W1. By adding the above output data, an output waveform output using a pickup at a position closer to the bridge can be obtained.

Example (Example 1) An example of the present invention will be described below with reference to the drawings.

FIG. 1 shows a block diagram of a musical tone synthesizer according to a first embodiment of the present invention. In FIG. 1, 11 is a delay section for temporarily storing waveform data, and 12 is a section for processing waveform data W2 that is temporally subsequent when waveform data W1 and W2 are taken out from different storage locations in the delay section 11. The bridge section 13 is an adder that adds the waveform data W3 and the output data of the bridge section 12. Other blocks are the same as before.

FIG. 2 shows a circuit diagram of the bridge section 12. In FIG. 2, reference numeral 21 is an inverter that inverts the waveform data output from the adder 84. The other circuits are similar to the circuit of the feedback section 52 shown in FIG. 8, and constitute a first-order low-pass filter.

Fig. 1 shows the musical tone synthesis device configured as described above.
The operation will be explained using FIG. 2, FIG. 10, and FIG. 11.

Since the basic operation is the same as that of the conventional musical tone synthesizer shown in FIG. 5, only the differences will be explained. In the conventional musical tone synthesizer, the operation of extracting musical tones from the bridge position shown in FIG. 10 was realized by extracting output waveform data from the output end of the delay section 51. On the other hand, in this embodiment, D shown in FIG.
In order to realize the operation of extracting musical tones from points, the waveform data W1, W are input from different storage locations in the delay section 11.
This was realized by extracting the waveform data W2 which temporally follows the waveform data W1, and further processing corresponding to the influence of the reflection of the bridge shown in FIG. 11. As a supplementary note, the actual string motion of an electric guitar is a mixture of two waves: a traveling wave going from point B to point 0 at point D in Figure 11, and a reflected wave going from point 0 to point B. The waveform is extracted by a pickup.

This operation will be explained as follows in comparison with the operation of the musical tone synthesizer shown in FIG. 1.

The right end of the delay section 11 in FIG.
Waveform data W1. Assume that the string is such that the storage position at the midpoint of the storage position from which W2 is extracted is the 0 point. Next, the traveling wave is waveform data W1, and the reflected wave is the bridge part 1.
2 output data. Furthermore, since the waveform taken out by the pickup is a mixture of the traveling wave and the reflected wave, the output waveform data is obtained by adding the waveform data W1 and the output data in an adder 13. Obtainable.

Here, if the influence of the bridge in FIG. 11 is considered as a low-pass filter process due to the inversion operation by the fixed end and the absorption of harmonic components of the waveform, the bridge section 12 functions as a first-order low-pass filter as shown in FIG. It can be realized by a circuit in which inverters 21 are connected in series. Note that for simplicity, it may be configured with only the inverter 21.

As described above, according to this embodiment, in order to realize an operation in which a mixed waveform of a traveling wave going from point B to point 0 and a reflected wave going from point 0 to point B shown in FIG. 11 is picked up by the pickup, To, the delay section! The waveform data W1 and W2 are extracted from different storage locations of the waveform data W.
1. The output output from the adder 13 by adding the waveform data W1 which has been processed by the bridge section 12 corresponding to the effect of the bridge on the temporally succeeding waveform data W2 of W2. The waveform data is the first
The waveform is very close to the waveform extracted from the pickup shown in Figure 1, and it is possible to provide a musical tone synthesizer that can produce the sound of an electric type guitar.

(Example 2) Example 2 of the present invention will be described below with reference to the drawings.

FIG. 3 shows a block diagram of a musical tone synthesizer according to a second embodiment of the present invention. In FIG. 3, 31 is a delay section for temporarily storing waveform data, and 32 is a delay section for storing waveform data W1, W2, . When W3 is extracted, the most temporally preceding waveform data W1
This mute section processes the waveform data W3 taken out from the midpoint between the storage position of the waveform data W2 and the storage position of the most temporally succeeding waveform data W2. Other blocks are the same as before.

FIG. 4(A) shows a circuit diagram of the mute section 32,
41 is a multiplier that multiplies the waveform data W3 output from the delay section 31 by preset mute data. Further, FIG. 4(B) shows a circuit diagram of the mute section 32, and 42 is a shifter that shifts the waveform data W3 outputted from the delay section 31 by preset mute data.

Fig. 3 shows the musical tone synthesis device configured as described above.
The operation will be explained using FIGS. 4 and 12.

This embodiment is a musical tone synthesis device that can be realized not only when string vibrations are directly picked up by a pickup at a point of contact as shown in FIG. 12, but also when they are input to a pickup from a bridge through a body.

This embodiment differs from Embodiment 1 in that the above-described system for inputting from the bridge to the pickup through the body is added. Therefore, as shown in FIG. 3, it is sufficient to add one input system to the adder 33 to the adder 13 in FIG. 1. Furthermore, the waveform input from the bridge to the pickup through the body has a significantly attenuated level because it passes through the body.

Therefore, as shown in FIG. 3, the added system requires a mute section 32 for level shifting. As this level shifting means, two methods using a multiplier or a shifter can be considered, as shown in FIGS. 4(A) and 4(B).

Now, here is the storage position of the delay section 31 from which the waveform data W3 is taken out.As is clear from FIG.
This is the middle of the storage location from which to retrieve. As mentioned above, in the case of electric guitars, in addition to extracting the waveform directly from the pickup, there is also a system in which the waveform is input to the pickup from the bridge through the body, albeit at a low level. However, among the electric type guitars, there are full acoustic type guitars whose body is the resonator. Since this type of device has a high level of waveform input from the bridge to the body, it can be realized by removing the C mute section 32 in FIG. 3 and directly inputting the waveform data W3 to the adder 33.

As described above, according to this embodiment, in order to realize the operation of picking up a mixed waveform of a traveling wave going from point B to point 0 and a reflected wave going from point 0 to point B, as shown in FIG. Then, the waveform data W1 . W2 is taken out and the waveform data W
1. Among W2, the waveform data W2 which is temporally subsequent to the waveform data W2 subjected to the processing of the bridge section 12 corresponding to the influence of the bridge is added to the waveform data W1, and the addition result W12) is further shown in FIG. In order to add the waveform taken out from the bridge shown to the output waveform, the waveform data W is added from the midpoint between the storage positions of the waveform data W1 and W2.
3, and the waveform data obtained by processing the waveform data W3 in the mute section 32 is added to the addition result W12, so that the output waveform data output from the adder 33 is picked up by the pickup shown in FIG. The output waveform is very close to the sum of the waveform input from the bridge to the pickup through the body, and it is possible to provide a musical tone synthesizer capable of producing the sound of an electric type guitar.

In the first and second embodiments, the input control unit selects either the drive waveform data or the feedback waveform data, but it goes without saying that it is also possible to add both data and use the addition result as the input waveform data. do not have.

Effects of the Invention As described above, waveform data (W1, W2) are extracted from different storage locations in the delay section, and the influence of the bridge on the temporally succeeding waveform (W2) among the extracted waveform data. By providing a bridge section that performs processing equivalent to , and an adder that adds the temporally preceding waveform data (W1) and the output data of the bridge section, it is possible to produce the sound of an electric type guitar. , the effect is great.

[Brief explanation of drawings]

1 is a block diagram of a musical tone synthesizer according to a first embodiment of the present invention, FIG. 2 is a circuit diagram of the bridge section 12, FIG. 3 is a block diagram of a musical tone synthesizer according to a second embodiment of the present invention, and FIG. FIG. 5 is a circuit diagram of the mute section 32. FIG. 6 is a block diagram of a conventional musical tone synthesis device, FIG. 7 is a circuit diagram of the delay section 51, and FIG. 8 is a circuit diagram of the feedback section 52.
9(A, ) is a circuit diagram of the input control section 53, FIG. 9(B) is a circuit diagram of the input control section 63, and FIGS.
FIG. 12 is a state diagram showing the sound generation form of the string. 11.31.51...Delay section, 52...Feedback section, 53.83...Input control section, 1
2...Bridge part, 13. 33.84.92・
...Adder, 21...Inverter, 41.82.
83... Multiplier, 81... Delay unit, 71.
...Shift register, 91...Selector. Name of agent Patent attorney Shigetaka Awano 1 person ε Fig. 10 Fig. 11 Fig. 12 De η - 5lX% De V Chosugin

Claims (1)

[Claims] (1) A delay unit that temporarily stores a plurality of waveform data, a feedback unit that processes the waveform data output from the delay unit, and a feedback unit that processes the waveform data output from the feedback unit and the waveform data provided from the outside. an input control section that outputs either of the generated drive waveform data to the delay section; a bridge section that processes the waveform data (W2) stored in an arbitrary storage position (A2) of the delay section; A musical tone synthesis device comprising: an adder for adding waveform data (W1) stored in a storage location (A1) different from an arbitrary storage location (A2) of the bridge section and output data of the bridge section. (2) Claim 1, wherein the bridge section is an inverter or a circuit in which an inverter and a first-order low-pass filter are connected in series.
The musical tone synthesis device described. (3) a delay section that temporarily stores a plurality of waveform data; a feedback section that processes the waveform data output from the delay section; an input control section that outputs either one to the delay section; a bridge section that processes the waveform data (W2) stored at an arbitrary storage location (A2) of the delay section; Waveform data (W3) stored in a storage location (A3) different from A2), and waveform data (W1) stored in a storage location (A1) of the delay section that is different from the storage locations (A2) and (A3). )
and an adder that performs addition with the output data of the bridge section. (4) Claim 3, wherein the bridge section is an inverter or a circuit in which an inverter and a first-order low-pass filter are connected in series.
The musical tone synthesis device described. (5) a delay section that temporarily stores a plurality of waveform data; a feedback section that processes the waveform data output from the delay section; an input control section that inputs one of them to the delay section; a bridge section that processes the waveform data (W2) stored at an arbitrary storage position (A2) of the delay section; A mute section that processes the waveform data (W3) stored at a storage location (A3) different from A2); and the storage locations (A2) and (A3) of the delay section.
The waveform data (W
1); and an adder for adding output data of the bridge section and output data of the mute section. (6) The musical tone synthesis device according to claim 5, wherein the mute section is a multiplier that multiplies the waveform data W3 by a predetermined value. (7) The musical tone synthesis device according to claim 5, wherein the mute section is a shifter that shifts the waveform data (W3) based on a predetermined value. (8) Claim 5, wherein the bridge section is an inverter or a circuit in which an inverter and a first-order low-pass filter are connected in series.
The musical tone synthesis device described. (9) a delay section that temporarily stores a plurality of waveform data; a feedback section that processes the waveform data output from the delay section; and a waveform data output from the feedback section and drive waveform data given from the outside. an input control unit that inputs the added value of the delay unit into the delay unit; a bridge unit that processes the waveform data (W2) stored at an arbitrary storage position (A2) of the delay unit; A musical tone synthesis device comprising an adder that adds waveform data (W1) stored in a storage location (A1) different from (A2) and output data of the bridge section. (10) The musical tone synthesis device according to claim 9, wherein the bridge section is an inverter or a circuit in which an inverter and a first-order low-pass filter are connected in series. (11) a delay section that temporarily stores a plurality of waveform data; a feedback section that processes the waveform data output from the delay section; and a waveform data output from the feedback section and drive waveform data given from the outside. an input control unit that inputs the added value of the delay unit into the delay unit; a bridge unit that processes the waveform data (W2) stored at an arbitrary storage position (A2) of the delay unit; Waveform data (W3) stored in a storage location (A3) different from (A2), and waveform data (W3) stored in a storage location (A1) of the delay section that is different from the storage locations (A2) and (A3). W1)
and an adder that performs addition with the output data of the bridge section. (12) The musical tone synthesis device according to claim 11, wherein the bridge section is an inverter or a circuit in which an inverter and a first-order low-pass filter are connected in series. (13) a delay unit that temporarily stores a plurality of waveform data; a feedback unit that processes the waveform data output from the delay unit; and a waveform data output from the feedback unit and externally applied drive waveform data. an input control unit that inputs the added value of the delay unit into the delay unit; a bridge unit that processes the waveform data (W2) stored at an arbitrary storage position (A2) of the delay unit; a mute section that processes waveform data (W3) stored in a storage location (A3) different from (A2); and the storage locations (A2) and (A3) of the delay section.
The waveform data (W
1); and an adder for adding output data of the bridge section and output data of the mute section. (14) The musical tone synthesis device according to claim 13, wherein the mute section is a multiplier that multiplies the waveform data (W3) by a predetermined value. (15) The musical tone synthesis device according to claim 13, wherein the mute section is a shifter that shifts the waveform data (W3) based on a predetermined value. (18) The musical tone synthesis device according to claim 13, wherein the bridge section is an inverter or a circuit in which an inverter and a first-order low-pass filter are connected in series. (17) Waveform data (W1, W2) are retrieved from mutually different storage locations in the delay section that temporarily stores a plurality of waveform data and the delay section, and among the retrieved waveform data, temporally subsequent waveform data ( A musical tone synthesis device comprising: a bridge section that performs processing corresponding to the influence of a bridge on W2); and an adder that adds temporally preceding waveform data (W1) and output data of the bridge section.