@lonemountain You are inferring something I did not say with this statement:
The idea that lower efficiency is always done as a cost saving excercise is clearly not true.
I don't need to repeat myself here. But it may interest you to know that high efficiency drivers, in particular woofers can be 10x more expensive than drivers of similar bandwidth and power handling that are not efficient. As an example the TAD 1602s (15", 97dB, Fs 22Hz) are typically $4000.00 each. Put a field coil into the mix and the driver gets even more expensive.
What I said when you quoted me is correct.