The subwoofer filter circuit allows the addition of subwoofers to an existing full-range system, offering adjustable low-pass filtering with optional R6 and R8 boost and mono-summing.
Skema Rangkaian 11-90 hz Subwoofer FilterUsing TL072 Op-Amp
The Subwoofer filter circuit to remove for separate pre amplifier to drive the low frequency sound a lot. In tone, call tone, normal Can not be done … is a fine deep low bass sounds like a bass drum, or at a movie complex in a low voice if we can be heard with But to add cabinets and amps. The subwoofer circuit is pass low frequency with in 11-90 Hz. Switching power supply 12V cut out if they need to use +-15V. I had change the Capacitor to cut out vocals per the red circle mark.