Physically these may alter the sound in the higher frequencies by adding harmonic overtones that ring well after the orignal excitation. (Studios use all kinds of tricks such as reverb etc. to give richness and provide hearing cues as to the location of elements in a sound stage...reverberation of higher frequencies provide detail on location of an instrument or voice)
Is this additional coloration better than the raw mix?...that will depend on your perception.
Is this additional coloration better than the raw mix?...that will depend on your perception.