Mark,

I don't know if PowerTracks has a built-in High-Pass filter, but the excellent series of plugins from Graham Yeadon in the UK has a High-Pass filter.

Get your copy (for free) from Graham's site at:

http://www.gvst.co.uk/downloads.htm

The High-Pass filter is named 'GHi'.

Just download the whole batch - His compressors are really instructive to use. Also get the Grymmjack skins for a slightly easier on the eyes version of the plugins.

By rolling-off, I just mean to set the cutoff frequency at 120 Hz. 'Roll-off' is used as a term because it's not an abrupt transition, but 'rolls off' in gain.

-Scott