It also doesn't mention that the AC3 file that is output from Acid Pro actually has a WAV header, that will throw off some authoring packages that are expecting to see a standard AC3 header. And I don't agree that "equal loudness contour" should be checked when measuring the RMS value; the A-weighted average sound pressure level you are trying to find is not equal loudness (according to the instructions that came with my Radioshack sound level meter, equal loadness is known as the C-weighted level).