The frequency response plots are: in room, listening position, DSP filter applied, physcoacoustic smoothing.
They show a response from 35Hz to 15KHz +/- 3dB for the frequency response.
The waterfall plot shows the benefits of the internal mechanical dampening systems. The engineering design of the internal assemblies, both in the horn metal ring and drive unit interface, and the steel legs with internal constrained layer dampening, giving a pretty even and low resonant system plot for the waterfall response. This results in greater clarity of the sound quality.