Equations for constant k high pass filters

At your risk. They are given on previous post with title: Shure SM58 connected to Pleiades (175mH:175mH) or EMI RS106A part 2 An important term is image impedance, see references on previous post. According to the book:Elements of Sound Recording - Frayne, Wolfe the T network should be 2C capacitor on left side, inductor L to ground, capacitor 2C on the right side. Network Pi should be on left side inductor L/2 to ground, Capacitor C on top sending music signal to the right inductor L/2 whose bottom side is connected to ground.