I'm an amateur at it but i have built a few mikes. I 've been surprised how the shell (and whats in it) can affect the sound,performance, of any one element. Good japanese dynamic elements can sound much better in some cases when they are put into bullet type shells.(sometimes a lot worse) Even C/Ms can vary a lot in the way they react to different shells and foams ,gaskets etc I have found the best way is to experiment a bit and try out different combinations of set ups.What sounds best ...is best. One thing for sure is you have to have an airtight seal around the element and no holes open in the shell itself. It'll be interesting to see what others have to say on this.We do have a few pro builders here ;-)