M Mdkanz New Member Apr 2, 2009 #1 Hi, I need a simple bandpass/lowpass filter schematic for a sub woofer.
Mike_2545 Super Moderator Apr 2, 2009 #2 I got this from a Google search **broken link removed** Here is another: Passive Crossover Networks And yet another: Low pass filter - Subwoofer - circuit diagrams, schematics, electronic projects Last edited: Apr 2, 2009
I got this from a Google search **broken link removed** Here is another: Passive Crossover Networks And yet another: Low pass filter - Subwoofer - circuit diagrams, schematics, electronic projects
audioguru Well-Known Member Most Helpful Member Apr 2, 2009 #4 The Lowpass Filter - Subwoofer... project was stolen from Electronics-Lab. It has an extremely poor translation and is full of errors.
The Lowpass Filter - Subwoofer... project was stolen from Electronics-Lab. It has an extremely poor translation and is full of errors.
Mike_2545 Super Moderator Apr 2, 2009 #5 audioguru said: The Lowpass Filter - Subwoofer... project was stolen from Electronics-Lab. It has an extremely poor translation and is full of errors. Click to expand... Well i don't endorse 'em I'm just pointing out the many design possibilities found by goggling your needs. I could have had him try this: Attachments band pass filter.jpeg 2.4 KB · Views: 624
audioguru said: The Lowpass Filter - Subwoofer... project was stolen from Electronics-Lab. It has an extremely poor translation and is full of errors. Click to expand... Well i don't endorse 'em I'm just pointing out the many design possibilities found by goggling your needs. I could have had him try this:
M Mdkanz New Member Apr 3, 2009 #6 Would just a simple resistor capacitor lowpass filter work? and if it would what should the value of the resistor/capacitor be?
Would just a simple resistor capacitor lowpass filter work? and if it would what should the value of the resistor/capacitor be?
audioguru Well-Known Member Most Helpful Member Apr 3, 2009 #7 A resistor feeding a capacitor to ground makes a very poor filter that has attenuation of only 6dB per octave or only 20dB per decade of frequency. If the cutoff frequency is 200Hz then 2kHz is attenuated only -20dB and is still audible. You don't want a sub-woofer producing mid-frequency sounds. If you use a 3rd-order Butterworth lowpass filter and if it has a cutoff frequency of 200Hz then 2kHz will be -60dB which is not audible.
A resistor feeding a capacitor to ground makes a very poor filter that has attenuation of only 6dB per octave or only 20dB per decade of frequency. If the cutoff frequency is 200Hz then 2kHz is attenuated only -20dB and is still audible. You don't want a sub-woofer producing mid-frequency sounds. If you use a 3rd-order Butterworth lowpass filter and if it has a cutoff frequency of 200Hz then 2kHz will be -60dB which is not audible.
L luxuchenghu New Member Apr 5, 2009 #8 Yes, just use MAX297, find the datasheet and there are formula for the capacitor.