mixxxdj/mixxx — pull request #299 by daschuer (2014-07-26 00:27:52+00:00)
Title: Linkwitzriley 8 EQ Effect

http://en.wikipedia.org/wiki/Linkwitz%E2%80%93Riley_filter

This one should sound better at the crossover frequencies compared to the butterwoth 8.
It has a constant phase shift = a non const, but linear goup delay.
It comes with a small amount of more CPU compared to butterworth 8
Gain ramping is not yet implemented.

IMHO it is a candidate to entirely replace the butterworth.