This circuit is useful for someone with DIY car stereo, portable active speaker or for 2.1 single supply audio amplifier...   Made in Slovakia

Cut-off frequency is set to 160 hz, which is just fine. If you want to tune it, change R10 Value.


500 Ohm - 318 Hz cutoff

2k -80 Hz cutoff


Use this tool to calculate cutoff:


I used double OpAmp, because they're easier and cheaper to buy here :) 


Contact me, to show where you used it please :)