On ways to gentle slope low cut microphone signals with minimum components

At your risk.


Using a Pleiades (R,L) filter connected in parallel (shunt) to mic's output.


Using a transformer with suitable primary inductance and core with the property that it's inductance index changes with frequency. For example mumetal.


Using 2 omnidirectional microphones connected in series out of phase, singing to one of them and adjusting the distance of the other.


Using 2 cardioid mics pointing in oposite directions and connected in series in phase. Proximity effects cancel. An omni mic is created.


Feeding the mic to a normal input transformer. Then driving a one stage active device mic booster amp and let the output transformer do the low cut.
See for example the Pleiades V6 when used at very low, for example 14mA anode current.


Note:
In general more low cut is needed if a male singer is singing softly [Lowe, Morgan] or at a high resister.


Reference:


Sound Picture recording and reproducing Characteristcs - D. P. Lowe, K. F. Morgan - JSMPE