1. Is the output of the capsule with a center connection lower compared to perimeter connection? Yes, but the difference is quite small because the stiffnes of the air dominates the stiffnes of the membrane (at least in Neumann capsules). I would expect the difference in sensitivity to be smaller than 1 dB. 2. Is the resonance frequency of the center connected by one octave higher? The resonance frequency of a membrane without any air is larger with the center connection. But it is not one octave. It depends on the diameter of the cental connection. For the fans of mathematics: The Eigenfunctions are not Bessel-functions of first kind anymore but a superposition of Bessel-functions of second kind. If you now put the capsule back in air the stiffness and the dissipation in the air make the resonances of both capsules quite similar (delta f < 1dB). Best regards Jürgen Breitlow Georg Neumann Berlin Microphone Development |