Its is certainly hiss.
Its not environmental.
Its being introduced because I am being forced to pump so much gain into the signal to get a usable amount of audio resolution.
As stated the threshold of those Sennheisers is much to high.
But, somehow I dont think thats going to be a problem...
I have a pair of Sennheiser E609S's, which have served me well when recording electric and for steel string acoustic.
But when I recently tried to record some nylon acoustic work it was clearly below the effective frequency range and response of these mics. I had to introduce so much post...