I've found that the listening room and listening location have a huge impact on whether a system is "warm" or "cold".
I moved my acoustic traps around to see how their location alters the frequency response (see my system in the Virtual Systems - the locations pictured are one optimum).
After fiddling for a while, I noticed that the better (flatter FR) locations had a dip from 40 to 300 Hz. The sound was "cold".
I flattened the frequency response (with assistance from my graphic EQ (GEQ) and REW) to +/- 5dB. Still on the cold side for me.
I re-adjusted my GEQ to gently boost these frequencies and to provide roughly a -1.8 dB/octave slope from 80 Hz upward (with help again from REW). The sound was "warm" and just as I like it.
One can achieve similar effects using digital filters although they must be used carefully. Calling for a lot of gain can cause railing (as can for GEQs).
The lesson for me is that location and sound absorption/scattering effects are much more important than contributions from individual components.
If one were willing to insert analog or digital filters into the system, then one could alter the system FR to one's taste. Within limits, of course.

