I'm not talking about the factor "bass in your stomach", which is an additional perception when you listen to music.
Also on headphones (so no body involved): systems with enhanced bass (from Loudspeakers to Flat Monitor) gives to me "better music".
But this "improvement" is due to what? Am I changing the content (thus the timbre) of the piece/instruments, since I'm manipulating the spectrum via different frequency responses? Or, if the content stay unaltered, what's the reason why I prefer enhanced bass?