Before closing, albeit even temporarily, I thought I'd harp on the Second Decade.
The so-called "Second Decade" is the range that commonly troubles live sound applications - it is the range where fundamental frequencies and related harmonics conspire to ruin attempts at feedback-free, clear live sound. This is a notoriously difficult range to "tame". It is right in the center of the vocal range, and is where acoustic guitars and other sources can very effectively be fattened or thinned. In short, it is critical. If at all possible, I would avoid a bi-amp crossover in that range, JMO.