would this work?
That looks like it should work.
...i dont need full spl readings, i just need any loudness information
If you need a "dB SPL" value, you'll need to calibrate your homemade meter with a known-good SPL meter. If you don't need the actual dB SPL reading, you can just take readings from the ADC (in the range of 0-1023*).
and fairly high loudness range...
...i just need any loudness information, even if the max is 50db
50dB SPL is not "loud". The [u]Wikipedia Chart[/u] says 40-60dB is "normal conversation".
- Since the Arduino can't read negative voltages, your microphone board may be biased at 2.5V (which will read ~512 with the default 5V reference).