Renmeister, there is a "free lunch" available when combining low-damping-factor specialty tube amplifiers and speakers designed to work well with such. The low damping factor in effect changes the woofer's electrical damping in a way that increases bass output relative to what you'd get with a solid state amp. If the speaker designer anticipated this, he has tuned the box so that instead of the lower damping factor giving you a bass hump, it gives you more extended low bass.
Aside from dynamics, one of the things a good horn speaker does well is radiation pattern control, and as a result the reverberant energy in the room usually has a similar spectral balance to the first-arrival sound. This is one of the ways in which a good horn system emulates the behavior of live instruments, and is generally not a characteristic of more conventional speakers (though as one might anticipate from my post just upthread, there are exceptions!). I believe that minimizing the spectral discrepancy between the direct and reverberant sound reduces listening fatigue, and can explain why if anyone is interested.
Aside from dynamics, one of the things a good horn speaker does well is radiation pattern control, and as a result the reverberant energy in the room usually has a similar spectral balance to the first-arrival sound. This is one of the ways in which a good horn system emulates the behavior of live instruments, and is generally not a characteristic of more conventional speakers (though as one might anticipate from my post just upthread, there are exceptions!). I believe that minimizing the spectral discrepancy between the direct and reverberant sound reduces listening fatigue, and can explain why if anyone is interested.

