It's not irrelevant nit picking. It's elementary science. Why did you throw your FR measurements away?
Just one of those things. Had I known that I'd be using them on the internet at some point then yes, a more conscious effort would have been made to save them. As it happened at the time it was purely for my own benefit.
Anyway as a self-proclaimed expert rather than hand-waving can you document the change in moving mass and demonstrate that it's negligible? What about the rather large change in damping factor?
Paul
I have to ask you what does this have to do with the measurements shown and the points raised? I think I already know the answer to that but I'll bite anyway.
Damping factor, you'd better start talking about amplifiers in that case. Unless your using something very unsuitable and inadequate such as a flea powered SET then your point is absolutely mute and the driver performance whether objective or subjective is unchanged between the Re variants.
Changes in Mms to the extent where the physical properties of the driver are identical and the extra mass comes from a very slightly heavier voice coil then the only real and notable difference will be sensitivity, thats all you should care about outside of mating drivers, partnering amplifiers and passive network design.
Since we don't have complete data sets for the 8 and 16ohm ATC to compare then for illustration I'll use another driver from Scanspeak, the 18W sliced paper:
8ohm version:
16ohm version:
Driver to driver tolerances even between identical models could illustrate a similar fractional FR deviation.
I could go on with other examples to further reinforce this. As I've said a couple of times before, ATC's drivers are no different to the above example.