It is the same....the whole reasoning behind this theory relates to the MCA controlling the velocity....that at a specific cross section and RPM the air will be travelling at a given velocity based in what the port flows....that this velocity...if it reaches a certain speed will sonic choke the port thus making power drop off after this point....the intact tract length controlling RPM is a different theory and relates to the range at which.sonic pulses will aid in cylinder filling based on the timing of the pulses to be synchronized with the intake valve opening.....