R can be drawn on the x or real axis.
L can be drawn on the y or imaginary axis. Imaginary because an inductance does not dissipate energy. It just stores energy and then gives it back.
The sum of R,L is the vector (R,ωL). Or R+jωL.
ω is angular velocity of rating vectors. ω=2πf or 2 x pi x frequency
R is constant with frequency.
But the reactance in ohms of an inductance is proportional to frequency.
So when a Pleiades (R,L) filter is connected across the output of a microphone:
high frequencies are left intact.
But mid, low frequencies are gradual shorted right the output of the mic.
L defines turnover frequency and R slope of the high pass curve.
The point is selecting suitable R,L values for a particular application so that frequency response is flat from producer's brain to listener's brain.
Usually without a Pleiades filter the sound at listener's brain can be very bass, mid frequency heavy. Due to Fletcher-Munson, Voice effort curves, tye proximity effect, boomy room acoustics etc.
See also:
Sound Picture Recording and Reproducing Characteristics - D. P. Lowe, K. F. Morgan - Journal of the Society of Motion Picture Engineers
Engineering Circuit Analysis - Hayt Jr, Kemmerly - McGraw Hill
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