There's an interesting discussion in a thread on DACs that I wanted to follow up on, but rather than clutter that one I thought I'd raise it in a new one.  The discussion was on how it sounded to the engineer when mastering the album and that we should maybe be striving to reproduce that (or maybe not!).  I have been looking at audio setup software etc recently and trying to understand what I need and the principles of measurement.  Not specifically for Hi-Fi though and more for some work projects (spectral analysis related to the effects of biofilm on the 'sound' of flow in a system) and to understand how to set a system up for a performance (a sideline for the village I live in when in the UK).  In a video by an experienced sound engineer he made an interesting comment on how they often measure and tune the sound system for a live performance in an auditorium and then add in extra low frequency etc to compensate for the presence of the audience, and to enhance the emotional impact of certain performances.  In other words, not a straight and faithful output of the input as it were.  Now, I wonder how that is reflected in studio engineering?