On 18 February 2013 12:51, robert bristow-johnson <r...@audioimagination.com> wrote: > > On 2/17/13 10:53 PM, robert bristow-johnson wrote: > >> On 2/17/13 9:45 PM, Jiri Prochazka wrote: >>> >>> Unfortunately it seems anything with>2 band isn't ideal end when >>> >>> the frequencies of the splits are near there is audible dB drop, >>> as can be seen on spectrum analyzer: >>> http://i.imgur.com/NI3ooO2.jpg >>> >>> Is there a way to fix this, or am I doing something wrong? >> >> > so i looked at this and could see that it *does* add up to an APF as it > should for a L-R crossover. but it need not be Q=1/4 as best as i can tell. > it seems like it could be nearly *any* Q if you do it like this: > > HPF: ( s^2 / (s^2 + s/Q + 1) )^2 > > BPF: ( 2 - 1/Q^2 ) * ( s / (s^2 + s/Q + 1) )^2 > > LPF: ( 1 / (s^2 + s/Q + 1) )^2 >
>From the image linked it looks like Jiri wants to have be able to have two independent cutoff frequencies for the crossovers, in this case one crossover at 2.4k and the other at 2.5k, and is noticing the cancellation issues if you have them close to each other like this. Andy -- cytomic - sound music software -- dupswapdrop -- the music-dsp mailing list and website: subscription info, FAQ, source code archive, list archive, book reviews, dsp links http://music.columbia.edu/cmc/music-dsp http://music.columbia.edu/mailman/listinfo/music-dsp
