hi Tenson

If you be familiar with electronics i think we can get a good idea.

in electronics for a system at first we define linearity accross frequency range and it mean : if we apply x1(t) to system we recieve y1(t) and like that y2(t) is response of x2(t). we say system is linear if we apply x1(t)+x2(t) and recieve y1(t)+y2(t).

i think linearity reffer to soundstage and microdynamic.

second for a linear system we define frequency domain function, amplitude and phase across frequency. every system like 'hifi plus accoustic of room' has these two response in frequency domain.

phase response and flat amplitude refer to neutrality, openness, transparency and frequency extension mean rise time in time domain analyse that i think it reffer to timing, pace, speed.

I know for accurate describing a system we need many parameteres but i like to simplify sound analysing with more important factors.