I Have Unity Horns, which are conical horns with entry ports for mid drivers, as well as a standard rear mount for the weeter.  I'm using TAD 2001's, and in this horn the response rolls off at 6dB/octave, starting about 4kHz.  The system is multi-amped and I'm using a DEQX to integrate the tweeter and mids, as well as for the woofers.  In order to preserve the full resolution of lthe system, I'd like to use an active filter in front of the tweeter amps, to compensate for the horn roll off. 

I want unity gain at frequencies below 4K, rising response at 6dB/octave above that, and probably leveling off at some point to prevent any high frequency instability.  THis struck me as being similar to part of an RIAA curve, but with different pole and zero points.  So I want a zero at 4k and a pole at let's say 50kHz.  I drew up a couple of simple circuits, one inverting, one non-inverting and calculated values using the nice little calculator here: http://www.hagtech.com/equalization.html Note that I've switched the designation of pole and zero, since the comp.  is applied as feedback, and is therefore inverted.  Anyway, here's the result.  Does this make any sense?  Think it'll work?