There are plenty of good horns out there, some that I would consider to be compatible, at least conceptually. The difficulty is knowing how they'll act in terms of summing, both on-axis and off-axis. Not only does response matter but also directivity and physical position, because each plays its part in setting the acoustic position and radiation pattern of the sound source. This makes it harder to know whether a horn will work as a drop-in replacement, or if crossover changes will be needed.Without doing some fairly extensive tests and measurements, I'd stick with the H290 or the π wood horn.