How to make a ribbon mic sound more detailed and bright than a condenser

There is no reason why they should sound only dark.


There is no reason why they shouldn't be at least as detailed as the best condensers or moving coils. Their diaphragm, the few micron thin aluminum ribbon itself is of extremely small mass. From Newton's law. Acceleration = force : mass . The lower the mass for given force the greater the acceleration.


They are tuned to a very low frequency.


So as the frequency is increased above this resonant frequency displacement drops as in all resonant curves. They are mass controlled.


But the velocity of the ribbon remains the same because the frequency is higher.


And since the emf or voltage out is proportional to velocity of a moving conductor in a magnetic field by the law of magnetic induction the voltage output with respect to frequency is constant.


This is the reason they are so good at high frequencies. Displacement of the ribbon is very small so there is no distortion. And they can handle the great sound of cymbals as for example the STC 4038s used by Alan Parsons on Dark Side of the Moon - Pink Floyd for drum overheads.


But when we sing close to them proximity effect increases the velocity at low, low mid, mid frequencies and output increases making them sounding dark.


An inductor in parallel with the mic does the trick of inverse compensating this effect (Pleiades filter).


And the filter can be chosen or adjusted until they sound flat for any particular distance.


See next post on how to equalize the Grampian GR1/L.


An inductor in parallel with the mic output is used on many world class directional microphones for low cut or high pass (making the resultant frequency response flat) such as the RCA 77DX, Electro-Voice RE15,...


References:


Microphones - Borwick


RCA 77DX manual


Electro-Voice RE15 manual