Wow, Jaguar, you may have asked the most unanswerable question ever asked on this board! The comment above about emotional content is right on the mark. This is not a technical issue, but one of artistic merit. Factors involved are the needs of the material, the needs of the singer, the needs of the room, the gear, and the listener. Every singer has some part of their vocal presentation that sucks. Sibilance, stridence, breathiness, etc. The perfect mic never accentuates that which sucks. The perfect mic boosts whatever part of the singer's voice is weak. The worse the room is, the less sensitive the perfect mic is. In a perfect room, the mic picks up that perfection. The perfect mic has a pickup pattern and a proximity field that is what the singer expects, so he/she can work that mic and get predictable results.
The perfect mic boosts frequencies that are attenuated by the preamp, and smooths out the peaks and valleys of the pre, but not so much that it removes a great pre's characteristic tonal profile. It also produces damn little self noise. Finally, the perfect mic produces a sound that the recording artist, the producer, and the mixing engineer all agree is appropriate to the material. It produces what we call "smile tracks". When you're halfway through the song, and everybody is smiling, you're on the way there. And that's what that emotional quality is all about. The perfect mic is the one that makes everybody want to listen to it again.-Richie
U87