Audio equalizers are indispensable tools for music enthusiasts to fine-tune the tonal quality of their audio systems. 3 Band Audio Equalizer Circuit is an active filter network that break the spectrum in three stage. This Circuit also known as Bass Mid Treble Control Circuit. Bass for the low Frequency, Mid for the mid Frequency, Treble for the High Frequency.
In this Blog Post,we discuss about the construction of a 3-Band Stereo Audio Equalizer Circuit using the 4558 operational amplifier IC.
3 Band Audio Equalizer Circuit Overview
3 Band Equalizer required 3 filters for each bands to control their respective frequency range
👉Treble (High-Frequency) Band:for controlling Treble
Employ a high-pass filter for the treble band.
Frequency for the treble band, typically ranging from 2kHz to 5kHz.
👉Midrange Band:for controlling Mid
Implement a band-pass filter for the midrange frequencies.
Midrange center frequency between 500Hz and 2kHz.
👉Bass (Low-Frequency) Band:for controlling Bass
Use a low-pass filter configuration for the bass band.
Frequency range for the bass band is from 60Hz to 150Hz.
The formula for determine the value of capacitors and resistors that use to cut off specific frequencies is-
fc = 1 / 2Ï€CR ---------C in farads ; R in ohms
OP-AMP IC Overview
FEATURES of 4558D OP-AMP IC
➤NO frequency compensation required
➤NO latch-up
➤Large common mode and differential voltage range
➤Parameter tracking cover temperature range
➤Gain and phase match between amplifiers
➤Internally frequency compensated
➤Low noise input transistors
Pin Configuration of 4558D OP-AMP IC
Components Required for 3 Band Audio Equalizer Circuit
Electrolytic Capacitors⇨4.7 μF/63v-6 pcs
Polyester Film Capacitor
⇨47 Pf-4 pcs
⇨103-2 pcs
⇨104-6 pcs
⇨152-2 pcs
⇨223-2 pcs
⇨683-2 pcs
Resistors
⇨1.5 KΩ-4 pcs
⇨6.8 KΩ-8 pcs
⇨8.2 KΩ-2 pcs
⇨10 KΩ-6 pcs
⇨22KΩ-2 pcs
Dual Potentiometer
⇨10KΩ-1 pcs
⇨47KΩ-2 pcs
⇨100KΩ-1 pcs
Power Supply-士 12 Volt DC.
Complete Circuit Diagram Of 3 Band Audio Equalizer Circuit
Explanation of the Bass Mid Treble Control Circuit
The circuit includes stereo input (IN L, IN R) and stereo output (OUT L, OUT R) connections for left and right audio channels.
1st Op amp IC is used for control Gain of input audio signal.Variable resistor are connected in the feedback path of op-amp to control the gain of the circuit.
The values of resistors and capacitors determined the desired frequency response and characteristics of the equalizer.You can experiment with capacitor and resistor values to fine-tune the frequency response of each band.
Potentiometers of the corresponding frequency bands(bass, midrange, and treble) adjust the amount of signal sent to 2nd Op amp IC.This Op amp IC is used as boosters of that audio signal.
Click on the Download buttons to download the Circuit Diagram of 3 Band Audio Equalizer Circuit.
Step By Step Video Tutorial Of 3 Band Audio Equalizer Circuit
Frequently Asked Questions
What is the purpose of an audio equalizer circuit?
Audio equalizer circuit allows adjust the intensity of specific frequency bands in an audio signal.
How to choose values for resistors and capacitors in the equalizer circuit?
The values of resistors and capacitors depend on the desired center frequencies and bandwidths for each frequency band. Formulas for filter design is fc = 1 / 2Ï€CR ,C in farads ; R in ohms.
What are the alternative of 4558 op-amp IC?
Popular alternatives of 4558 op-amp are TL072, TL082, and NE5532.
