My suggestion:
1. Build/have built two "artificial" corners for the Klipsch speakers;
each wall to be at least four feet long from the back of the Klipsch,
see #2 photo in this thread:
viewtopic.php?f=17&t=6798&p=47658&hilit=+Klipschorns#p47658
I have been using ONLY these two horn loaded systems exclusively for
Hauptwerk organs in "simple" stereo for some time. Sound is
as good as any of the many other set-ups I have tried with all my
possible multi-channel audio experiments. You MUST have the walls
to support the lowest tones from the Klipschorns. They must be the
same height as the bass horn outout port from the back of the Klipsch.
Using your Echofire preamp in stereo only, the two stereo output channel ports,
allows the headphone port output with separate level control to be available.
If you use more ports of the Echofire, the headphone output is disabled.
Try it, you will like it. I took down the two Behringers from the console top;
they added nothing to the tone sound.