After reading extensively on digital filters used as crossovers,
I just finished implementing a digital LR-4 crossover filter using 2
chained butterworths 2 pole q=1/sqrt(2).
I used the bilinear transform method to calculate the coefficients of
the butterworth filter and chained 2 of them together to make the
Linkwitz-Riley.
I wrote a simple calf plugin using this dsp. The frequency response
curve of the output shows accurate 24dB/octave rolloff with white
noise fed into the filter, however the highpass filter curve shows
considerable noise at low frequencies (under 40Hz).
Should I be using a different algorithm? I read somewhere that
"biquad" is a good method, but I have no idea how to do it.
Regards,
Damien
_______________________________________________
Linux-audio-dev mailing list
Linux-audio-dev@email-addr-hidden
http://lists.linuxaudio.org/mailman/listinfo/linux-audio-dev
Received on Sun Aug 30 04:15:02 2009
This archive was generated by hypermail 2.1.8 : Sun Aug 30 2009 - 04:15:02 EEST