So I went and bought a Yamaha 661 receiver, specifically to be able to play uncompressed audio tracks from Blu-ray discs. My first few experiences were pretty positive. I was able to hear a definite difference between the PCM and Dolby Digital tracks of Blackhawk Down and Tears of the Sun. I was feeling pretty good about my purchase decision.... until last weekend.
I decided to watch Underworld Evolution. I switched back and forth between the PCM and Dolby Digital track at various points in the movie. I was shocked to discover that certain scenes sounded better to me in Dolby Digital!!! Also, the Dolby track was noticeably louder than the PCM track. Isn't one of the effects of audio compression a general lowering of volume? I've noticed that on regular DVD's the DTS tracks always sound louder than the Dolby tracks.
Thinking that maybe what I was hearing on Underworld was just an aberration, I went about my daily life. But last night, I rented the Blu-ray of Casino Royale, and experienced the same thing. The Dolby track was quite a bit louder than the PCM track. But at least I can't say that the Dolby track sounded better to me.
What's going on here?!?!