Sierra 2 Users: Anyone using a HSU High Pass Filter Optimizer?

Anyone used this to bypass the lowest frequencies to their Sierra-2? They let you pick 2 crossover frequencies from 30 - 150 Hz.

What would you recommend as the frequecies to use? I am thinking 80 Hz for option 1 and 100 or 120 Hz for option 2.

Thoughts?

http://www.hsuresearch.com/products/...ss-filter.html

http://www.hsuresearch.com/products/...imizer-250.jpg

Here is an alternate option:

http://www.hlabs.com/products/crosso...es/Page395.htm