Wednesday, August 31, 2016

Subwoofer filter using one transistor

Subwoofer filter using one transistor is very very simple for filtering your subwoofer tone control. This circuit diagram for subwoofer filer using one of transistor :
Subwoofer filter using one transistor circuit diagram
Subwoofer filter is using for filtering audio tone signal, subwoofer tone about 40Hz - 100Hz. Input audio is stereo , and output to mono subwoofer output. It' very simple subwoofer filter, you just need a few component resistor and capasitor, and basically strenghening by 1 transistor , the transistor just using C945 ot C828

Component list Subwoofer filter using one transistor :
  • Q1   C945 / C828
  • C1   1 Uf
  • C2   100nf /ceramix104
  • C3   1uf
  • C4   1uf
  • C5   1uf
  • C6   1uf
  • C7   100uf
  • R1   10k
  • R2   47ohm
  • R3   220k/470k
  • R4   10k
  • R5   10k
  • R6   10k
  • R7   1k
  • R8   2k2

Electronic Circuit is a good site for hobbyist also who would like to try DIY because it shared good circuits. If you have a personalized circuit requirement you may feel free to request it through the comment box or contact me.


Hi Wahyu,
Thank you for these simple circuits. I am a hobbyist but not good in electronics. I am making a portable 2.1 speaker (using PAM8403 like class d setup) and need subwoofer filter circuit which can be run using li-ion battery 3.7v (ex: battery 18650). I will be using single supply ICs like lm358 or LM324. however i am unable to find any suitable circuits and whichever i tried created lots of distortion. could you please suggest some battery operated single supply 20 to 150 HZ filter circuit. If the circuit is 2.1 channel then that is also good. I was even going through you other circuit from the article below. can i use the single supply ICs like lm358 or lm324 for the same circuits below with a li ion battery?

from article above mono premamp>300HZ LPF>PAM8403 thats all. Please suggest best lowpass (20- 150 HZ?)circuit which can implement for my portable speaker project. Thank you once again.

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