I was not aware the mic could take up to the neighborhood of 10v for some reason. Yes, I will definitely reduce the resistance to 15k. I will be sure to only use that calculator for my leds from now on.
On the last point, I will build another circuit with the regulated 5v feeding everything and see what results I get. I may eliminate the resistor before the mic altogether for that test circuit. So, 5v to the mic, the DVR and the circuit. I guess I can leave the voltage divider as is and expect 2.5v to pin3...
thanks again for your help and patience.