E
Eric Griswold
Does anybody know this one?
I have a sealed speaker whose acoustic rolloff response is a chebychev
2nd-order highpass filter with a cutoff frequency of 119 Hz and a Q of 1.0.
I want to add an first-order active highpass filter before the power amp, to
make a compound, 3rd-order Butterworth response overall.
I know that a first-order highpass has a Q of .707 so when I multiply that
by the speaker's Q of 1.0 I will have a final Q of .707 which is
Butterworth, just how I want it.
What I don't know, is what frequency to make the active filter, and what the
final cutoff frequency will be.
Can I place the active filter at 119 Hz too? Bt then the overall -3dB point
will move a little higher, won't it? Where will it go?
Thanks,
eric g.
I have a sealed speaker whose acoustic rolloff response is a chebychev
2nd-order highpass filter with a cutoff frequency of 119 Hz and a Q of 1.0.
I want to add an first-order active highpass filter before the power amp, to
make a compound, 3rd-order Butterworth response overall.
I know that a first-order highpass has a Q of .707 so when I multiply that
by the speaker's Q of 1.0 I will have a final Q of .707 which is
Butterworth, just how I want it.
What I don't know, is what frequency to make the active filter, and what the
final cutoff frequency will be.
Can I place the active filter at 119 Hz too? Bt then the overall -3dB point
will move a little higher, won't it? Where will it go?
Thanks,
eric g.
