With the bass and midrange/treble horn mouth ends in the same plane, I could not really see or hear any advantage to adding delay to the midrange/treble signal to achieve "time-alignment". Therefore, it appears as if nothing is lost by mounting the whole huge speaker flush with an interior or exterior wall in a building, for example.
Last night I processed several music tracks by mixing from stereo to mono, and remixing a stereo track with the bass horn right channel low-pass filtered and the midrange/treble left channel high-pass filtered. I had processed the square-wave tracks in the same way in order to "split" the bass and midrange/treble information so as to be able to introduce a relative delay in the midrange/treble. This processing simulates a "bi-amped" setup with active crossover.
I hope to listen to these tracks sometime today.
Here is the inspiration for the Sound Transformer Project. Below is a photo of the horn-loaded Theater Loudspeaker designed by Albert L Thuras and Edward C Wente and reported in the March, 1934, edition of the Bell Labs Record Vol 12, No 7.
|Theater Loudspeaker by Albert L Thuras and Edward C Wente|