JPS61167212A - Digital graphic equalizer - Google Patents

Abstract

PURPOSE:To confirm easily the frequency characteristic by providing a display section displaying a peak level after level varying operation at each frequency band. CONSTITUTION:Switches SW1-SW8 operating variably an output level of a filter having a center frequency or a cut-off frequency at each frequency and a switch SWt operating variably the entire band level are provided to an operating section 91. Further, a display section 141 is provided with display element groups 151-158, 15t in a form of bar graph corresponding to the switches SW1-SWt. When a switch, e.g., SW5 of the operation section 91 is detected for variable operation of a prescribed amount, the degree of effect between frequency bands is added to a signal of a frequency band to adjacent switches SW4, SW6. Then the peak level of a transmission characteristic at the center frequency or the cut-off frequency is displayed to a display element group of the display section 141.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application The present invention relates to a digital graphic equalizer;
The present invention relates to a graphic equalizer that outputs a digital audio signal such as a PCM audio signal by varying the level for each frequency band.

Conventional techniques include, for example, a so-called graphic equalizer that divides an audio signal into a plurality of frequency bands and increases or attenuates the level for each band. A "digital filter device" described in the above publication is known.

FIG. 7 shows a block diagram of an example of the main parts of a general digital graphic equalizer. The digital audio signal input to the terminal 1 is passed through a low-pass filter 21. which has the frequency characteristics shown in FIG. Bandpass filter 22. ..., is divided into frequency bands by a high-pass filter 2n and taken out from a terminal 3. In this case, each filter 21 to 2n is a secondary 11R
For example, in the filter 21, the multiplication coefficient of the multiplier 4 is K as shown in FIG.

al, a2+,' bl, b2, and the delays caused by the delay element 5 are expressed as z-' and z-2. M is the transfer function 1-1 (Z-'), and the configuration can be changed or each By changing the coefficients, each frequency characteristic can be easily obtained, and the gain of each frequency band can also be changed.

By the way, since the frequency characteristics of the filters of adjacent and adjacent frequencies are added to the frequency characteristics of the - filter among the filters 21 to 2n shown in FIG. The peak level characteristics are different from the set level. Therefore, in the conventional digital graphic equalizer, the degree of influence by the adjacent and Il# adjacent frequency bands is calculated in advance, and along with the operation of increasing and attenuating the level of the - frequency band, the influence of the adjacent and adjacent frequency bands is adjusted. It was designed to change the frequency characteristics of the set level so that the peak level characteristics match.

Problems to be Solved by the Invention Conventional graphic equalizers are not configured to display peak level characteristics. There was a problem that the status could not be confirmed.

SUMMARY OF THE INVENTION An object of the present invention is to provide a digital graphic equalizer that displays peak level characteristics for each frequency band after a level variable operation and allows easy confirmation of the frequency characteristics.

The reason why graphic equalizers do not change the frequency characteristics of the adjacent and adjacent frequencies is that they generally adjust the sound roughly, and for that purpose, it is better to have the influence of the adjacent and adjacent frequency bands. Rather, this is because it is often favorable, and the peak level is confirmed while actively utilizing their mutual influence.

Means for Solving the Problems In FIG. 2, a display section 141 is an embodiment of a display means for displaying the peak level.

By variable operation of the effect switches SW1 to SWt, the degree of influence between the frequency bands is added and the peak level is displayed for each frequency band on the display section 141.

Embodiment FIG. 1 shows a schematic block diagram of an embodiment of the graphic equalizer of the present invention. In the figure, the digital audio signal input to terminal 1 is a digital signal.
The frequency band is divided by digital signal processing in the processor 6, and the level is increased and attenuated, and the signal is output to the terminal 7.
taken out from The CPU 8 is activated by operating the operating section 9.
The algorithm shown in the flowcharts (Figures 3 and 5) described later is executed in accordance with the control program of M10, and the data stored in RAM 11 that has been divided in advance by the degree of influence of the acid phase of each frequency band is calculated. It controls the calculations in the digital signal processing unit 1. The memory control unit 12 receives the control signal from the CPU 8 from the RA.
Data stored in M13 is controlled to control high speed calculations in digital signal processor 6.

The display section 14 displays the peak level of frequency characteristics for each frequency band in accordance with the level enhancement and level attenuation operations performed by the operation section 9, and is an important part of the present invention.

FIG. 2 shows a schematic front view of an embodiment of the display section and operation section of the graphic equalizer of the present invention.

For example, the operation unit 91 has 75H2, 150H2, 300H.
z, 600Hz, 1.2kHz,
2.4 kHz, 4.8kl-IZ, 9.
A switch S for variable operation of the output level of the filter having a center frequency or cutoff frequency of 6 kF-1z, respectively.
A switch SWt for variable operation of W+ to SW8 and the entire band level is provided.

The display unit 141 is provided with display element groups 15 to 15s and 15t configured in a bar graph shape using, for example, a plurality of LEDs, corresponding to the switches SW1 to SWt.

Here, it is detected that the switch S W s of the operation unit 91, for example, is variably operated by a predetermined amount (step 10 in FIG. 3).
0), then the adjacent switches SW4 and SWs
The degree of influence between the frequency bands is added to the signal of the frequency band corresponding to J (step 101), and the peak which is the transfer characteristic at each center frequency or cutoff frequency is displayed on the display element groups 151 to 15t of the display section 141. The level is displayed (step 102).

FIG. 4 shows a schematic front view of another embodiment of the display section and operation section of the graphic equalizer of the present invention.

The operation unit 92 includes switches SW+a to SWga that lower the output level corresponding to each of the frequency bands mentioned above.

5Wta, switch SW+ to increase the output level of (
b to SWa'b and 5Wtb are provided.

Switch SW+ a ~5Wta, SW+ b ~SW
ab.

For example, when swtb is operated, that part is displayed as a setting level. Display section 142
The display element group 16 corresponds to each switch of the operation section 92.
1 to 16g and 16t are provided, and each display element group is composed of a peak level display section 16A on the right side thereof and a set level display section 16B on the left side thereof.

Here, for example, it is detected that the switch 5Wsb is variably operated by a predetermined amount (step 103 in FIG. 5), and then,
Setting level display section 165 of operated switch 5Wsb
B is lit (step 104), and then the influence between the frequency bands is added to the characteristics of the frequency band corresponding to the adjacent switch SW4.8Ws (step 1).
05), display element groups 161 to 16g of display section 142,
16t peak level display section 161A to 16aA, 16
The respective actual levels are displayed on tA (step 106
).

The level displayed on the set level display section can also be used to reproduce the obtained frequency characteristics.

FIG. 6 shows a schematic diagram of still another embodiment of the display section of the graphic equalizer of the present invention. This device uses an X-axis driver 17a for each display element group of the display section 143, which is composed of, for example, a fluorescent display tube.

The display is driven using respective drive signals from the Y-axis driver 171). In addition to this, L F is used as a display section.
Possible sources include O, plasma, liquid crystal, etc.

Although not described in detail, in each embodiment, a switch that can vary the Q may be provided for each frequency band on the operating section (for example, only SWo+ is shown in FIG. 2); in this case, the Q The degree of influence caused by the variable is also calculated and displayed on the display section.

Effects of the Invention The digital graphic equalizer of the present invention is
A display section is provided to display the actual transfer characteristics for each frequency band, making it easy to check the frequency characteristics.
It is easier to perform level variable operations, and since the peak level display section and set level display section are arranged side by side, it is easy to check the level relationship between the set amount and the actual characteristics, allowing you to accurately set and reproduce the desired characteristics. It has features such as being easy to use.

[Brief explanation of the drawing]

FIG. 1 is a block system diagram of an embodiment of the equalizer of the present invention, FIGS. 2 and 3 are a schematic front view and a flowchart for explaining the operation of an embodiment of the display section and operation section of the equalizer of the present invention, and FIG. 5 and 5 are a schematic front view and a flow chart for explaining the operation of another embodiment of the display section and operation section of the equalizer of the present invention, and FIG. 6 is a schematic diagram of still another embodiment of the display section of the equalizer of the present invention. , FIG. 7, and FIG. 8 are a block system diagram and a frequency characteristic diagram of an example of a main part of a general digital graphic equalizer, respectively. 1... Digital audio signal input terminal, 6... Digital signal processor, 7... Output terminal, 8
...CPU, 9.9+, 92...Operation unit, 10.
...ROM, 11.13...RAM, 12...memory control unit, 14.14+, 142.143...
- Display section, 151-15g, 15t, 16+-168° 161...Display element group, 161A-168A. 16tA...Peak level display section, 16+e to 16a
a, 1618-setting level display section, 17a...
X-axis driver, 17b...Y-axis driver, S W +
~SWs, SWj, SW+ a ~SWa a,
5Wia. SW+b~SWab, 5Wtb... Level variable switch. Figure 2 JP-A-1-167212 (4) Figure 3 Figure 5 Figure 4 16.1 Vessel 165B 165A168B 16Q', 6
8A16t・・□・・−1 central 0

Claims (2)

[Claims] (1) A digital graphic equalizer that sets transmission characteristics for each frequency band by adding the degree of influence between the frequency bands by operating a level variable switch provided corresponding to each frequency band. A digital graphic equalizer comprising a display section that displays actual transfer characteristics for each of the frequency bands. (2) The display section has a display section that displays the set level obtained by operating the level variable switch in parallel to a display section that displays the transfer characteristics after operating the level variable switch for each frequency band. A digital graphic equalizer according to claim 1, characterized in that: