[wazoo2u]

Originally Posted by jameskg

FM radio rolls off hard at around 15kHz. (The response is 15kHz wide and starts at 50Hz or so).

James,

Actually, there is no lower frequency limit to FM broadcasting, only the 15kHz upper range (as you mentioned). Looking through the FCC Part 73 specs, I don't see anything addressing highpass filtering.
(http://www.scott-inc.com/html/fccrules.htm)

Also, see:
http://www.radio-electronics.com/inf...ffm/vhf_fm.php
for a pretty nice explanation of FM mux/demux.

I guess I should add that the individual FM receiver will probably be the limiting factor, not the broadcast.