I am looking for processors that have FIR filtering. The XDP-4000X I have on the way does but I am also interested in others such as Audison, Helix, Mosconi, etc. I know that PPI, Soundstream and other miniDSP based models might not since miniDSP does not have FIR filtering except for in their miniSharc which requires separate DACs. Before I spend hours researching the net today, has anyone already considered this? Thanks!