I think saying the Walsh speaks including As and Fs are pistonic is an accurate statement.
Regarding efficiency, though I would not doubt the DDD driver is more efficient than the original Walsh A or F drivers from 30 years ago, I think comparing a full range driver like those on the Ohm A and F to a limited range driver that does not cover the low end like the DDD is an apples and oranges comparison.
Regarding efficiency, though I would not doubt the DDD driver is more efficient than the original Walsh A or F drivers from 30 years ago, I think comparing a full range driver like those on the Ohm A and F to a limited range driver that does not cover the low end like the DDD is an apples and oranges comparison.