Tone Circuit Constant Calculation Examples

Super Bass Band Circuit

The equivalent circuit and the formula for calculating the external RC with a mean frequency of 68 Hz are shown

below.

• Super bass band equivalent circuit block diagram

• Calculation example

Specification Mean frequency: f0 = 68 Hz

Gain during maximum boost: G = 20 dB

Let us use R1 = 0, R2 = 66.6 k

Ω, and C1 = C2 = C.

We obtain R3 from G = 20 dB.

We obtain C from mean frequency f0 = 68 Hz.

We obtain Q.

No. 6866-15/24

LC75421M

C1

R1

R2

R3

C2

G

+20 dB

= 20 × LOG

10

1

+

R2

2R3

R3

=

R2

66600

2

× (10 – 1)

=

≠ 3.7 KΩ

f 0

=

R3R2C1C2

1

2

π

C

=

=

1

2

πf0 R3R2

1

2

π × 68 66600 × 3700

≠ 0.15 µF

Q

=

R3R2

R3R2

2R3

1

≠ 2.1