1. Probably a group within the military, the majority of which was without serious audio knowledge, put out specs to be met by any potential builder - so that's what was built for them. That, or knowledge of other things was behind the idea and the specs given hide other possibilities not revealed.

2. Hmm ... the ET TRW-17 ... I remember some folks worrying about an Outlaw product of several years ago regarding some very minor hiss they could hear when placing their ears 6" from a tweeter in their system. Even with physical and acoustic damping, am I not going to hear the TRW-17 whirring away at idle if the environment is otherwise quiet enough? In the right environment, the TRW-17 might be really impressive, like the driver for a very large outdoor bass horn, or in a club which is almost continously pumping out high amplitudes across much of the audio spectrum, but in the normal smaller environment of a house something else may be more suitable.