Adjusting capsule diaphragm tension

Has anyone experimented with this? I understand that the capacitance and sensitivity is proportional to tension. I'm just curious about it. I've never read a discussion about the topic that discuss actual methods on any of the forums.

AusTex64 said:

I understand that the capacitance and sensitivity is proportional to tension.

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That is not true. Capacitance depends on diaphragm area and gap. Now sensitivity may be altered when changing the tension, by indirectly changing the damping, but also changing the frequency response.
Beware that in many European languages, tension means voltage (as in HT<=> High Tension), and yes, sensitivity increases with voltage.

There are two capacitances of a true capacitor microphone capsule.
One is capacitance defined with effective area of diaphragm, distance between electrodes and electric properties of the insulator.  It doesn't depends of diaphragm tension (if the tension is high enough so there is no irregularity in the diaphragm surface). It also has more academic importance here IMO because it presumes there is no DC voltage or differential pressure applied.
Second one is capacitance when nominal DC polarization voltage is applied, and yes, this capacitance depends of the diaphragm tension and it is relevant value for all measurements and calculations.

More info can be found here:
http://www.bksv.com/doc/be1447.pdf

moamps said:

Second one is capacitance when nominal DC polarization voltage is applied, and yes, this capacitance depends of the diaphragm tension and it is relevant value for all measurements and calculations.

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That's correct; however, increasing tension by itself does not change the nominal capacitance. Increasing diaphragm tension allows using higher polarization voltage (bias) before the diaphragm collapses. But it also changes the tuning, which may or may not be compensated by modifying the hole pattern of the backplate. I don't think it's doable by a DIYer.