The formula and all of the transition frequencies are given in Sec. The lower the transition frequency, the more HF boost there is in reproduction, making more HF headroom, and more HF noise to go with it. Thus constant flux plus head plus integrator equals constant output voltage vs frequency. This simply means that the integration is stopped at that frequency. In reality, all of those things have to be corrected or compensated.
Eq are a whole 'nother stories, if anyone's interested.
A 10-dB increase in apparent dynamic range is realized for some digital audio systems. A survey of peak acoustic levels present in 36 music performances is also included. Without a doubt, it is far from optimum. NAB eq was designed for 3M 111 tape in the late 1940s. It was appropriate in its day.