That's interesting Dave - do you think that when you use the 'noisy' mics, you ever notice? I'm just wondering that these noise figures really don't make any real practical sense in terms of saying X is worse than Y. I've been recording today with two of the 'noisy' mics and I cannot hear this noise I can measure? Again, your comment on the hums and spikey sounds also seem to cloud the results we get. Clearly one of my mics is faulty - the noise being a very strange sound, not jus hiss. I think I'll repeater the tests at some point but at the moment, I'm falling a bit behind. I'm also wondering if the sensitive mics, would benefit from the lower gain setting. Maybe the hiss generated in the preamp could be more problematic than the extra hiss from the mic? Do the two things work together, in reverse. I get more hiss from the 414 because it's relative output is greater, so if, say it is 4 times more sensitive, but the extra hiss twice as loud, then turning the gain down to a quarter removes twice as much hiss? Just scratching my head on how these things work.
I suppose I could take a tone generator at a measure ddistance and then see how far down the noise floor is??