Subwoofer Low Pass Filter Circuit using Op-Amp TL062 that let low sound go and block high sound, also this circuit is good for subwoofers which gives deep and strong bass.
The circuit uses TL062 op-amp which is active for low pass type and it cut high sound and keep bass clean and loud.
Also, STMicroelectronics designed the TL062 IC with two JFET-input operational amplifiers and moreover, it offers low power consumption and fast response, making it a good choice for audio applications and suitable for this circuit.
Moreover, circuit use +12V and -12V power and help it work better.
Circuit Working:
Parts List:
| Components | Values | Quantity |
|---|---|---|
| Resistors (All resistors are 1/4 watt unless specified) | 220Ω | 1 |
| 39k, 4.7k, 10Ω | 2 each | |
| Potentiometer 47k | 1 | |
| Potentiometer 22k | 2 | |
| Capacitors | Ceramic 39pF, 0.47µF, 0.22µF | 1 each |
| Ceramic 0.1µF | 4 | |
| Semiconductors | IC TLC062 | 1 |
This Circuit diagram above uses op-amps and some passive parts like resistors, capacitors and power parts.
First op-amp part work as active low pass filter and second part does more filter and make signal strong, then left and right input go through R1, R2 and then reach inverting input of op-amp which work as low pass filter.
Then cutoff frequency set by VR1 and C1 and after filter, the signal goes to next stage for more process.
After that, second op-amp part is second order low pass filter and final filter changes by VR2, VR3, R4, R5, C4, C5.
Output signal (filtered) go to subwoofer amp through R7 and further, TL062 op-amp IC uses ±12V power.
Also, capacitors C2, C3, C6, C7 which are 0.1µF and resistors R3 and R6 which are 10Ω help keep power stable and circuit smooth.
Formulas with Calculations:
Below are formulas with calculations for Subwoofer Low Pass Filter using TL062 op-amp:
Cutoff Frequency (Fc):
Fc = 1 / (2 × π × R × C)
First Stage:
R = 47kΩ (47000Ω)
C = 39pF (39 × 10⁻¹² F)
Fc = 1 / (2 × 3.1416 × 47000 × 39 × 10⁻¹²)
Fc = 83.6 kHz
Second Stage:
Fc = 1 / (2 × π × √(VR2 × VR3 × C4 × C5))
VR2 = 22kΩ (22000Ω)
VR3 = 22kΩ (22000Ω)
C4 = 0.47µF (0.47 × 10⁻⁶ F)
C5 = 0.22µF (0.22 × 10⁻⁶ F)
Fc = 1 / (2 × 3.1416 × √(22000 × 22000 × 0.47 × 10⁻⁶ × 0.22 × 10⁻⁶))
Fc = 100 Hz
Circuit let sound below 100 Hz pass easily and high sound get weak which is good for subwoofer use.
How to Build:
To build a Subwoofer Low Pass Filter Circuit using Op-Amp TL062 follow below should for connection:
- First, pin 1 of IC1 go to one side of VR1 and other side of VR1 go to pin 2 of IC1
- Then resistor R2 from left audio input go to pin 2 of IC1 and then capacitor C1 connect parallel with VR1
- After that, resistor R1 from pin 2 of IC1go to right audio input.
- Now pin 3 of IC1 go to GND and also pin 4 of IC1 go to -12V through R6 and also connect C6 and C7 which is parallel from this point to GND
- Further, center pin of VR2 and VR3 go to one side of C4 and other side of C4 go to pin 6 of IC1
- Next, resistor R5 one side go to VR3 and other side go to C5 and then to GND
- Then pin 5 of IC1 connect at point between R5 and C5 and then resistor R4 go to pin 1 of IC1 and other end of R1 go to VR2 pin
- Also, pin 7 of IC1 connect to pin 6 and also pin 7 go to audio output through R7
- Finally, pin 8 of IC1 go to +12V through R3 and connect C2 and C3 parallel from here to GND
12V Dual Power Supply for the above Circuit:
Working of 12V dual power supply circuit:
A center-tapped transformer with a 1 A rating steps down 220 V AC to 14-0-14 V AC and the center tap serves as the ground (GND) connection.
Four 1N5402 diodes form the bridge rectifier.
D1 + D3 work in positive half and D2 + D4 work in negative half.
The rectifier converts AC to pulsating DC and two 1000 µF, 25 V capacitors C1 and C2 smooth the DC output and reduce ripple.
Output becomes approx with +19V and -19V DC before regulation and 7812 IC1 regulate +19V DC to +12V DC and 7912 IC2 regulate -19V DC to -12V DC.
Then C3, C4 are 0.1µF capacitors help remove high frequency noise and keep voltage clean.
Final result shows: IC1 7812 gives +12V DC, IC2 7912 gives -12V DC and GND is center tap and it is good dual supply for op-amps, audio amps and circuits which need ±12V DC.
Conclusion:
Overall, this Subwoofer Low Pass Filter Circuit using Op-Amp TL062 is a good and useful project., as it remove high sounds and boost bass.
Also, it use TL062 op-amp and make sound clear and stable and if required , we can change cutoff by adjusting resistor and capacitor which fit many audio setups.
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