I appreciate the rather different philosophy involved in the constant directivity cornerhorn and the Klipschorn. But I am still interested in knowing whether digital compensation can be used to achieve constant directivity with the Klipschorn bass horn. Clearly constant and linear phase (delay) can be compensated. Are you saying that nonlinear phase (frequency dependent group delay) is the issue? I would think that could also be compensated provided it could be measured or calculated.
But I will say that even if your midhorn and tweeter is just used to achieve some constant directivity in the mids and highs along with increased smoothness in the 200-400 Hz region then that is a big step forward with the Klipschorn. Building large tractrix horns along with 2" compression drivers to reach lower cant in fact get low enough, is really expensive and has directivity problems