The shape of the mike holder might also be affecting your results. If it is flat then it is probably picking up sound from 180 degrees.
The mic is facing downward, almost 6mm facing the surface (table). My usable gain was only 5.... (changing the value of 82 to 2K and 82K to 10K).
Increasing the gain causes strong noise.
If you put it at the bottom of a cone, its angle of pickup will be narrower but sensitivity will also increase.
Im using omnidirectional mic, is unidirectional may help reduce the noise?
By the way, did you verify that this is not a noise canceling unit or one intended for noisy areas? Those are intentionally designed not to pick up any source that is not within a couple of inches of its diaphragm.
If you wont mind can you explain this one, or maybe links that could help me to understand? Can you site sample schematic for noise cancelling?