I really like the Klipschorn a lot, so I don't want to knock it too much. It sounds nice. But there are a few things I never liked about the design, and the seven π addresses these problems. For one thing, the Klipschorn bass bin is used much too high for a folded basshorn. This gives vocals and other midrange a sort of woody sound. The Klipschorn midrange driver is also pushed too low. The transition between bass and midrange is strained as a result.

Midrange from 200Hz up is all-important. This is where the fundamentals of many instruments fall - piano, guitar, voice, everything. You really don't want this band passing through long labyrinthine folded-basshorn passages as used in the Klipschorn. This causes standing waves with associated peaks and notches in response, path length delays that make proper summing impossible, panel vibrations and other unwanted problems.

The seven π midhorn is set so that it crosses-over from the bass bin at a low enough frequency to be within 1/4λ, maintaining single-point source operation. It is large enough that the low frequency midrange driver does not strain it at all. You can really hear the improvement in sound quality using this approach.