The Shure SM7 seems to have a presence cut filter...

Not a presence boost filter.


It can be seen on the schematic that an inductor in series with a capacitor filter is switched to attenuate the inherent presence peak:
https://pubs.shure.com/view/guide/546/en-US.pdf?clean_category=User%20Guide


So how would SM57, SM58, Beyer M88 etc sound with such a passive LC filter connected in parallel with their output? The Sennheiser MD441 seems to have a similar filter.


Would it be nice to have such a Pleiades filter inside a Neutrik XLR module female to male adaptor?


Next day's addition:


A more accurate title should be...
The SM7 seems to have a high frequency reduction filter ie a presence filter.


It can be read that the SM7 has a similar although not identical capsule to the Unidyne III, SM57, SM58 etc.


This suggests that there is an inherent high frequency broad peak or rise. It can be seen on the frequency response curves of all theses microphones.


The LC filter is a broadband attenuator designed to reduce such rise and make frequency response as flat as possible.


So high frequency reduction when the filter is activated by the switch means that mid band, say 2.5KHz is now louder compared to high frequency. This means increased presence if we look at Fletcher Munson equal loudness curves.


It may be fun experimenting with LC R values for the other microphones too.
At reasonace the reactance of L in ohms equals the reactance of C in ohms. Since the vectors are of opposite direction, total reactance becomes 0 and we are left with the resistance of the L coil plus any extra R added in series. R is the real part of impedance. Reactance is the imaginary part or the vector representing it is at right angles.


If R is arranged to be half the output impedance of the mic, the mic output drop at reasonace will be to half voltage broadband ie -6dB.


So by playing around with L, C, R a mic could approach the fiat frequency response of an SM7 which seems to have such a filter designed to it like a glove.