Paul,

Firstly no it's not hearsay I'm afraid. I'll show you the boards at the factory if you would like. It's fact.

 Secondly the devices are the same. They do in fact make the S and the standard model , the difference only being in efficency. Both are available to special order at 16 ohm devices should a client require them. There are no special devices made by ATC only for their own speakers that sound better than others. Come on! Do you really think they would tool up for that? Have you watched the domes being made? It's yet another example of ATC owners trying to bypass evidence that suggests there may be some minor issues with their products IMHO.

Thirdly it is not the low end that affects the upper midrange - please read the post. The upper midrange is crossover over too high I believe on the monitors (3.5khz?). That's only a quarter of an octave below the first major resonance. Even with a fourth order slope, it will only be 9db down at that point - not sufficient to remove it's influence IME. As a bear minimum I would crossover half an octave before the resonance fourth order - as other users do. There is of course an issue also at the bottom of it's pass band.