How does the Shure SM59 microphone operate?

Referring to patent US3989905, assignee Shure Brothers Inc, inventors C. Roger Anderson, Eduard A. Rusch, Charles E. Seeler.


Mechano-pneumatic shock mount means that air molecules are automatically sent to the back of the diaphragm in order to cancel handing noise.
The cartridge is supported by 2 compliant toroidal supports.
There is a diaphragm at the end of one of the chambers.
Adjustable pressure build up? and adjustable air leak is used to make the SM59 one the less vibration immune microphones.


Here is a small extract from the patent description:


Assuming a shock force is applied to casing 100 in the direction of the arrow F (the patemt document shows a force in the direction of the axis of the microphone towards XLR connector), casing 100 momentarily moves to the left relative to housing 30, thereby creating a slight pressure in cavity 90. A small percentage of shock force F is coupled to housing 30, thereby through shock mounts 122 and 132 so that transducer assembly 28 tends to move to the left relative to diaphragm 12 and voice coil 24, which are resiliency mounted  on transducer assembly 28. This relative movement between transducer assembly 28 and voice coil 24 would normally produce an electrical output from the microphone. However, the pressure in cavity 90 tends to move diaphragm 12 to the left in step with the movement of transducer assembly 28, so that the relative movement between voice coil 24 and transducer assembly 28 is minimized.
Pressure from cavity 90 is coupled to side 15 (back of diaphragm) of diaphragm 12 through rear entry channel 94 in the manner previously described in order to keep diaphragm 12 in step with assembly
28.
By using components of the type described and adjusting the components in the manner taught, the output of the microphone due to mechanical shocks applied to casing 100 in a direction parallel to axis 20 may be substantially reduced over a wide of frequencies.


Reference:


Patent US3989905


PS


It is impressive how low handing nose this microphone has.
And how great the sound quality is.