[music-dsp] Digital Crossover Network Filters

[yon]

> Well yes, in theory you want linear phase filters so that you get a 
> phase
> aligned IR from your drivers.

Linkwitz-Riley is one IIR crossover design which is widely used for 
this purpose.  This is a Butterworth-based design has a matched-phase 
characteristic, which is important in the transition band.  The order 
of the design is  variable, so that you can choose a filter order with 
as narrow a transition band as you need.  The tradeoffs are performance 
and, eventually, transient response.

You can find quite a bit of other information about crossover designs 
on the internet.  There is a pretty down-to-earth Rane technical report 
on Linkwitz-Riley crossovers that you should be able to find by 
searching, and there are other resources related to speaker hobbyists.

Cheers,
Yon