# Low pass filter 25Hz to 150Hz

If you have been looking for a circuit that will allow only Low pass audio frequency (Bass), this is for you! It is a low pass filter 25Hz to 150Hz circuits that cuts high frequencies from sound and leave only the low frequencies.

When you listen to music or any audio sound, sometimes you feel sound that shakes or vibrates you or an object around the surrounding. The sound responsible for the vibration feelings is the “LOW” or “BASS” sound. This sound has lower frequencies which are between 25Hz and 150Hz. Any sounds beyond these frequencies are categorized as “MID” or “High.”

This article will put you through constructing the LOW pass filter circuit which its frequency ranges from 20Hz to 150Hz that you can use for subwoofers.

As mentioned earlier, audio frequencies are of different ranges starting from LOW to MID and HIGH frequencies (Hz – KHz). So, I guessed you want to cut off those HIGH frequencies and leave only the LOW right? This project is a circuit that filters audio frequency from the range of 25Hz to 150Hz for subwoofers.

Its output is fed to the input of subwoofer amplifier. The circuit is base on op-amp integrated circuit JRC4588, it uses dual rail i.e. positive and negative with ground (GND) DC power supply. See Dual Rail DC power supply here.

#### COMPONENTS USED

1. Integrate Circuit (IC)
• JRC4588 or JRC4558
• 1KΩ (3)
• 5KΩ (1)
• 10KΩ (3)
• 51KΩ (1)
• 22µF (2)
• 100nF (1)
• 0.63pF (1)
• 150nF (1)

Below is the circuits diagram of the low pass filter 25Hz to 150Hz of frequencies.

###### Components Values
• R1, R4, and R5=10KΩ
• R2=51KΩ
• R3=1.5KΩ
• R6, R7, and R8=1KΩ
• C1=100nF
• C2 and C5=22µF
• C3=0.63pF
• C4=150nF

Find Ceramic capacitors (non polarized capacitors) with their number codes and values in pF, nF, and µF respectively here>> capacitor number code