I've been doing a lot of critical listening (read, obsessing) lately with my various mics.
I always took the view, get better mics and/or add soundboard to get better and better sound. That is true, but what is the *best* sound I can get?
For neutrality and transparency, the best I have heard are the Sennheiser symmetrical capsule MKH series (MKH 20, 30, 40 etc.).
The symmetrical design lowers intermodulation distortion amazingly and makes these the most neutral, uncoloured and revealing mics around.
The first time I heard a recording of the human voice on a demo CD I felt myself relaxing and saying "that's right" and the same voice through the other mics sounded "recorded".
If you want to hear, I have a copy of the original Sennheiser demo CD where you hear the effects of IM-distortion and noise - I ripped this from the original CD (deleted many years ago) and have put a few of my own recordings made with these mics. on the end.
Not knocking any other mics, as mic. colouration is an integral part of choosing what mic. to use in what situation - but for clear, uncoloured sound that let's you really hear what is there, these are unbeatable.