Calculating high and low pass filters

[jon]

I'm working on a Fender Vibratone and I am trying to figure out the crossover. I know that the system is supposed to send all the mids to to the Vibratone and the lows and highs back to the main amp. How do I calculate the frequency that are being sent to the Vibratone? Additionally, can someone explain to me the total effective load on the amp assuming that the Vibratone has a 4ohm speaker and the main amp has a 8ohm speaker, and what would happen if I changed the Vibratone speaker to 8ohms

[Reeltarded]

Backlink to the other filters:

http://sim.okawa-denshi.jp/en/CRhikeisan.htm

Question 2. Hmmm.. Dunno.

Q3: warble drops about (really almost) 6db in the warble.