It's fairly typical for the level of dialog to vary from movie to movie. The standard is
supposed to be -31 dB and again the mastering engineer is
supposed to include a DialNorm value in the bitstream that indicates the actual level of the dialog so that the receiver can boost or attenuate it to bring it to -31 dB. The problem is that not all receivers look at the DialNorm value (THX certified receivers do) and even when they do the DialNorm value may not be accurate.
- You can always bump up the center channel level to suit your tastes rather than leave it at the 'correct' calibrated value.
- Muddy or low dialog is often caused by center channel placement or room acoustics problems. You can experiment with placement of the center or better yet read up on this site about room treatment.
- You can use dynamic range compression (aka 'midnight mode' on some receivers) to compress the dynamic range. The explosions will be less loud because the range between soft and loud will be compressed, but dialog intelligibility is often improved.
- You could try using PLII Music mode which allows you to adjust Center Width (how center info is spread between L/R/C) and Dimension (move the center image forward or backward).
OR you could keep the remote in your hand at all times and fiddle with the volume like the rest of us do.
