OK, so I know from reading the forums that the Radio Shack meters are not the best for calibration but I'm more or less using this program to try and plot sub woofer response. My question is about calibrating the dB level. When I attach my meter to the computer and set it to the 80 dB range the needle on the meter basically stays around 82 dB. I have tried to change the range and it still stays in that same spot. The microphone appears to be working properly because i can see the spectrum display reacts to noises but I can't figure out how I'm supposed to calibrate at 75 dB when the needle doesn't move. When the meter is disconnected from the computer it works fine. :scratch: How can i calibrate this thing?!