JPS6084003A - Loudness control circuit - Google Patents

Abstract

PURPOSE:To prevent reduction of audible sense related to the Fletcher-Munson characteristic at a small sound volume by providing a sound volume tracking frequency characteristic change means changing the frequency characteristic in response to the sound volume adjustment volume so as to correct automatically the frequency characteristic at the small sound volume. CONSTITUTION:In maximizing sound volume by turning clockwise the knob of a sound volume adjusting volume 7, a slider 7c and an end point terminal 7b are allowed to contact and a slider 6c of a frequency characteristic changing volume 6 is allowed to contact also with an end point terminal 6b. Thus, only a sound signal through an amplifier 10 is given to the slider 7b and the frequency characteristic is unchanged. In turning counterclockwise the sound volume adjusting volume 7, the sound volume is decreased and also the slider 6c of the frequency characteristic changing volume 6 is slid in the direction of a start point terminal 6a, only a high frequency component through a bypass filter 2 is amplified and added via a resistor R1, and the high frequency components of the frequency characteristic are emphasized. Thus, the reduction in the audible sense related to the Fletcher-Munson characteristic is corrected.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a loudness control circuit, and more particularly to a loudness control circuit that changes the frequency characteristics of high I and low frequencies in the audible frequency band in accordance with the volume.

Conventionally, the frequency characteristics of the audible frequency band are different from the standard frequency characteristics depending on the purpose. In the standard frequency af-1+]-y audible frequency band, there is a so-called Fletcher-Munson characteristic, which is a phenomenon in which the audibility deteriorates in the high and low frequencies when the volume becomes small. In order to deal with this problem, the level k of the high and low ranges, or either the high range or the low range.
A loudness control circuit is provided to correct +iQ, and a push button or rotation type] ゛6)'X1! Manipulate materials to change frequency characteristics.

In the present invention, the sound J[1- is set to a small γ'r
Frequency automatically when set to f'+1! 1. An object of the present invention is to provide a loudness control circuit that can change the harp characteristic and respond to Fletcher Munson characteristics.

Hereinafter, an embodiment of the loudness control circuit according to the present invention will be explained in detail with reference to FIG.

In FIG. 1, 2 is a bypass filter, 6 is a volume for adjusting the frequency characteristic, and 7 is a volume for adjusting the frequency characteristic. Poly for changing frequency characteristics, -Muro and sound fk
? A i running ha? Ream 7 is a rotary variable resistor Z:)
When it is formed coaxially and coaxially clockwise, "1" 6
c and 7c are from the starting point side terminals 6a, 7a to the ending point side terminal 6
b, slide in direction 7b. The audio signal input from the 9111i child 1 is passed through the high-speed filter through the amplifier 5 to the starting point 1+10ψ of the IP filter for changing frequency characteristics.
1°M is sent to the child 6a. The end point side terminal 6b is connected to the reference potential point. When the slider 6c is at the position of the starting point side terminal 6a, the output level to each subsequent circuit is at its maximum, but when it slides toward the end point side island, the first child 6b, it decreases, and at the end point side terminal 6b, the output level is the maximum. It becomes the reference potential point.

The input 4JIlj of the amplifier 10 is connected to the terminal 1, and the output side is connected to the end point side 7b'' of the volume control volume IJ, 7 through the resistor R2. The transducer 6c of No. 6 is connected to the terminal terminal 7b of the volume control volume 7 through a resistor R1.The amplifier 10 amplifies the entire range of audible frequencies by a typical frequency characteristic.

Here, if you turn the knob of the accessory bone adjustment volume 7 clockwise to make the volume maximum, the slider 7c and the end point I11]ψ
; 11 contacts 7b, )^'' jS mover 6c of the wave number characteristic changing polymer 6 also comes into contact with the end point side terminal 6b. For this reason, the slider 7b (all amplifiers 10 and 10) sends out only the low-frequency audio signal. Government officials don't use telephones. For volume adjustment l force j? When the ream 7 is rotated in the counterclockwise direction, the volume becomes silent. sound!・: is small ft-r,
': then s for changing frequency characteristics; Ream 6 slide 1
Since the 110 element 6C moves in the direction of the starting point ml 9'' 6 element 6a, only the high frequency portion through the pass filter 2 is increased IIr, and is added via the resistor R1. !11′ emphasizes the high frequency side.For this reason, the decrease in audibility related to Fletcher Munson characteristics is 1l.
ii to be correct.

Fig. 2 is another example of the loudness control circuit 11.The frequency characteristic changing circuit 11 is J,';]i Tip'1
Movable contacts 12c and 1 of relay 12 for S
;・Frequency characteristics are changed by the closed circuit at point 12b of υ operation J22. Frequency・1. (The switching relay 12 operates with a signal obtained by averaging detection of the audio signal on the output side of the amplifier 8). Note that D1&:L diode +R3+R4 is resistor C1l:J combination.

In the embodiment shown in FIG. 1, correction is performed on the high frequency side, but the low frequency 1! 4i11 correction may be applied only to II or to both high and low frequencies.

The loudness control circuit that will be used in this project is IJ,
- Since the structure is equipped with a volume tracking type layer wave number characteristic changing means to improve the frequency characteristics according to the sound i,, k, and j by the system control means, when the volume becomes small, the frequency 11, It has the feature that it is automatically corrected. Therefore, it is possible to prevent the hearing sensation from being deteriorated due to the Frette-Yarmanson characteristic at low volumes.

[Brief explanation of drawings]

1 id is a block diagram showing an embodiment of the loudness control circuit by J. Kino, b (FIG. 32 is a block diagram showing another example of FIG.
2u bypass filter, 3 is capacitor, 4 is resistor, 5
, 8, 10, 13.14 are amplifiers, 6 is IJ for changing frequency conductivity, -mu, 7 is yl? for volume adjustment. 9 is a speaker, 11 is a frequency characteristic changing circuit, and 12 is a frequency characteristic switching relay. Patent applicant Yaesu Musen Co., Ltd. Figure 1 Figure 2

Claims (1)

[Claims] 1. A loudness control circuit equipped with a frequency characteristic changing means for changing the frequency characteristics of high and low frequencies in the audible frequency band, comprising a goliame control means for adjusting the volume of the audible frequency band; and 4. Volume control. and a sound star following type frequency characteristic changing means for changing the frequency characteristic according to the soundscape adjustment by the means, and is characterized in that the frequency characteristic of the audible frequency band is changed according to the volume. loudness control circuit.