3 Jul
2012
3 Jul
'12
6:59 p.m.
On Tue, Jul 3, 2012 at 11:41 AM, S. Massy <lists(a)wolfdream.ca> wrote:
Hello, all,
Here's a question for the fine DSP and accoustic experts on this list. I
need to apply different processing (mostly reverb and compression) to
different bandwidths of the frequency spectrum on a given track. How
would I go about using filters to implement crossovers as flat as
possible? Most plugins do not actually seem to tell what their rolloff
curve is.
Thanks.
Cheers,
s.M.
Your choices are limited by the bandwidth and center frequencies you choose.
When you choose the quality factor to get a certain phase/magnitude
characteristic, that determines your bandwidth:cutoff freq ratio for
resonant filters.
I would defer to more experienced members on the list--but I think
your best choice is to use 2nd order low-pass/high-pass pairs with
Q=0.5. That will get you a reasonable (but not perfect)
reconstruction and nice flat response.
To get perfect reconstruction--with the limitation of 1-octave band
filters--you can use wavelets and their associated mirror quadrature
filters.
Chuck