On Sun, Oct 03, 2010 at 12:31:59PM +0200, Philipp Überbacher wrote: > Afaik, -3dB == cutoff frequency, at least with those passive electronic > single pole low/highpass filters. They are second order, using biquads. With first order this problem wouldn't exist as 1/(1+s) + s(1+s) = 1. > So If I understand that and read the > picture correctly, you refer to the frequency range between the cutoff > of the low-band and the lower cutoff of the mid-band, which is about > 300Hz, as well as the upper cutoff of the mid-band and the cutoff of the > high-band, which looks even wider to me, about 400Hz. What you see is not the shape of each filter, but how they combine. The lowpass is of the form 1/(1 + d s + s^2), the higphass is s^2/(1 + d s + s^2), s = j f / fxover, d > 0. The nominator of the sum doesn't have any term in s, and the two others cancel at the xover frequency where s = j. Hence gain is zero at the xover frequency. > I also wonder a bit why the 3kHz dip is at 3.1kHz.. Just a small gain difference in the compressors. If you bypass them the dip is at exactly the set frequency. Ciao, -- FA There are three of them, and Alleline. _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/listinfo/linux-audio-user
