I'm very out of date. My experience with horns, including those of Klipsch, was for monaural listening. The rational for such horns, placed in the corner of a room, was that the adjacent walls extended the horn. The sectoral horn used in several of the systems for high frequencies was an extension of concept. I had thought stereo killed them off, because few rooms could accomodate a pair of corner horns.
In the old days there were a number of such systems (unsure of spelling, JBL Hartsfield, ElectroVoice Patrician, Altec Voice of the Theater, and Klipschhorn to name a few. But along came Edgar Villcher at Acoustic Research with his long-excursion air-suspension speakers, and tar began pouring over the monsters. The small boxes lent themselves to stereo. Since then, there seems to be a general return to ported reflex enclosures. IIRC, Bozak was the first to use many moderate size cones to displace air.
So the answer to the question of whether Klipshorns are mainly for classical music is obviously no. Anyone have a JBL Hartsfield out there? At the time, I thought they sounded great, but problably wouldn't now.
Paul Klipsche and Edgar Villcher had several interesting debates at the annual Acoustical Society of America meetings, and I must admit to deserting the psysiological and psychological sessions to attend those debates. One of the great PK lines was something like, I don't care if you push it with a broom handle, you still have to move the diaphram to displace air.
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