No. 6866-20/24

LC75421M

(4) Bass Peaking Circuit

The equivalent circuit and the formula for calculating the external RC with a mean frequency of 100 Hz are shown

below.

• Bass band equivalent circuit diagram

• Calculation example

Specification Mean frequency: f0 = 100 Hz

Gain during maximum boost: G = 11.9 dB

Let us use R1 = 0, R2 = 45.084 k

Ω, and C1 = C2 = C.

We obtain R3 from G = 11.9 dB.

We obtain C from mean frequency f0 = 100 Hz.

We obtain Q.

C1

C2

R1

R2

R3

G

+11.9 dB

= 20 × LOG

10

1

+

R2

2R3

R3

=

R2

45084

2

× (3.936 – 1)

=

≠ 7.68 KΩ

f 0

=

R3R2C1C2

1

2

π

C

=

=

1

2

πf0 R3R2

1

2

π × 100 45084 × 7680

≠ 0.082 µF

Q

=

R3R2

R3R2

2R3

1

•

≠ 1.66

Simulation Results

Setting

f = 100 Hz

f = 1 kHz

11.9 dB

11.88

0.00

10.2 dB

10.38

0.00

8.5 dB

8.79

0.00

6.8 dB

7.14

0.00

5.1 dB

5.42

0.00

3.4 dB

3.66

0.00

1.7 dB

1.85

0.00