Any slope filter can be realized by cascading a bunch of 1st and 2nd order filters and punching in the correct Q factor. For Butterworth: 1st order -> 1st order real pole filter 2nd order -> 2nd order with Q = 0.707 3rd order -> 1st + 2nd with Q = 1. 4th order -> 2nd with Q = 1.31 + 2nd with Q = 0.54 and so on.. A complete Q-factor look-up table for most common filters can be found at the end of this datasheet (p.56) http://focus.ti.com/lit/ml/sloa088/sloa088.pdf The KX package currently has just 2nd order filters which limits such implementations only to even order slopes. I have successfully implemented odd orders but I haven't compiled an Effects-Plugin yet. This screenshot shows how to realize a 6th order Butterworth slope (36dB/oct) with 3 cascaded EQ Lowpass plugins. 6th order Butterworth is shown in green. 4th in red and 2nd in blue are there for reference.