Alot of microphone jacks on laptops have a boost setting. Is that turned off?
Make surer the meter's dial is set for 80 dB.Just had a thought -- The cal reading is taken from the RS meter visual meter. The measurement is from the electronic RCA output. Could the offset be the result of that big a mismatch between the two?
Not allowed. The Radio Shack Meter is a line level device - not a microphone.I run REW on my Dell laptop I use the microphone in