Small plug-in in DX format (suitable for Sonar MIDI FX bin), 32bit/64bit with "free hard" digitally precise arbitrary response curve can be found there:
http://www.azslow.com/index.php/topic,275.0.html To Forum Hosts. Before you instantly move this topic to Software/Hardware/Deals boards:
a) the plug-in is dedicated for Sonar (from my knowledge it is useless for other DAWs)
b) it is not an Ad, it is free, it was written as an attempt to help some users (and without any other intention)
c) there was related questions in this board