A way to close mic an instrument while making it sound natural in space

Natural as when we listen to the source of sound from relative far in a natural environment?


Maybe yes.


The Pleiades filter is a way,


The low mic distance gives a loud sound with less hiss.


No room reverberation.


Reduced leakage.


The Pleiades filter is an inductor in parallel to the microphone output.


It high passes the signal so that:


The proximity bass increase effect,
The Fletcher-Munson curves describing our brain perception,
And the effort curves (voice effort curves) describing how the spectrum of real instruments is changed by how softly or loud they are played.
Are compensated.

The above 3 give in general an increased bass to our brain perception.


This bass increase may be compensated with Pleiades filters.


So the sound is as possible flat in frequency responce not from mic to loudspeaker but for example from vocal chords of singer to the listener's brain.


The mic then sounds loud, clear and natural to our brain.


Pleiades filters as perhaps the simplest filters ever conceived.


A Pleiades filter is just an inductor, a coil connected to the microphone output.


The number of turns wound on a magnetic (usually) ring core adjusts for bass cut ie permissible closeness of mic to source of sound.


It works great for moving coil, ribbon and condenser microphones. It should also pass phantom power as there is nothing in series with the signal.


After a Pleiades filter is connected a much easier signal gets into the preamp or prepreamp.


Pleiades concepts are open source.


An easy implementation is inside an XLR female to make adaptor.


Pleiades filters were used since many decades inside for example Electro-Voice RE16 moving coil microphones or RCA ribbon microphones.


A reference is given with a schematic by the RCA director Harry Olson who developed the ribbon microphone.


And a musical example of Amy Wibehouse singing with the RCA 77DX ribbon mic which has the compensating inductor Pleiades filter inside it


https://m.youtube.com/watch?v=3su4q5fVGQg



References:


Ribbon Velocity Microphones - Harry F. Olson - JAES June 1970


http://www.coutant.org/rca77dx/