From the website:
“bx_cleansweep is a new Hi-Pass and Lo-Pass filter plug-in, introducing the new “Anti Crush Technology” (originally developed by Brainworx).
Analog style filter curves without the typical Nyquist problems, in a new great sounding filter design (taken from our pro mastering EQ bx_digital V2). First order filters (6 dB per octave) guarantee an extremely musically sounding filter set, and unique joystick control (taken from bx_hybrid) gives you fast and intuitive control.”
This plugin is now part of the Plugin Alliance
Free! Go get it.