I have it working powered from the board's 3.3v and ground but when I try it with the battery power it is not very sensitive at all. Like I have to clap close to or tap the microphone to get a .25 volt reading.
There's supposed to be a gain/sensitivity pot on the back of the board. The power supply voltage wont' change the gain (assuming it's adequate) but a higher supply voltage will allow a larger output-voltage swing before clipping (distortion).
Hi bmoe24x,Is I see, this mic is a simple electret mic with built-in preamplifier. I am sure that you can power it with seaparated battery. In this case the "external" battery should be connected to the GND and VCC pins of microphone. You must then connect microphone's GND to Arduino GND and microphone's OUT to the desired Arduino input. It should work.As the amplifier on the microphone module needs a power supply of 2.4-5.5V, I would recommend a 3xAA or 3xAAA battery case for mic power (instead of a 9V battery with that over-complicated power regulator that you linked).Regards,Zoltan