AmplifierCircuits

General Description        This subwoofer active filter circuit is a 24 dB octave filter with a Bessel character and cutoff frequency of 200 Hz. So, if you are interested in experimenting with audio circuits in subwoofer range, this circuit is for you. In subwoofer range, all audio frequencies below 200 Hz can be fed to a single speaker box since the human directional perception of sound diminishes at this frequency range. The normal stereo signals above 200 Hz can be fed to 2 satellite speakers. How does the subwoofer filter works: A1 and A2 buffer the signals coming from right and left channels. Opamp combinations A2/A4 and A9/A10 function as the highpass filters. The outputs are then connected to the final amplifiers of the battelite boxes. Signals from both channels are fed to A5. Opamps A6/A7 function as the lowpassfilter, A8 as the output amplifier for the subwoofer signal. The signal level can be balanced between the subwoofer and the satellite lines. The ...

Cheap car subwoofer filter circuit description:      This subwoofer filter set Suitable for use with a great car audio system. Since this circuit is designed to operate with a 12 volt DC power. But if you put it to use with a home stereo, It do not have any rules. This subwoofer circuit set is designed to has a cut off frequencies of 200 Hz. If you are not satisfied, you can change the C6, C7, C8, new, follow the table below.       The left cannel input signal is entered pass through capacitors C1, C3 are the output Signal to the original circuit. (Or rear left in the car). And the right cannel input signal is entered to C2, C4 to the original circuit. (Or rear right in the car).  Two resistors R1 and R2 will be mixer audio signal the left channel and the right channel both together. Then next wire connects to C5. This capacitor is also know as the coupling capacitor to inverting input of M5218A (IC1a).  The VR1 serves as a set of IC1a ...