Uncompressed audio

[darien87]

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?!?!

 

[emorphien]

Probably just differences in mastering, which also affects whether a DVD-A or SACD sounds better than the regular CD version.

 

[no. 5]

It may be worth noting that human hearing almost always considers the louder sound to be better, so if the DD track is louder than the PCM track, your ears may be telling you that DD is better when it may not be.

It has been my experience that compressed music sounds louder than its uncompressed equivalent, if MDS chimes in here, he will have a better explanation of compression then I.

 

[darien87]

It may be worth noting that human hearing almost always considers the louder sound to be better, so if the DD track is louder than the PCM track, your ears may be telling you that DD is better when it may not be.

It has been my experience that compressed music sounds louder than its uncompressed equivalent, if MDS chimes in here, he will have a better explanation of compression then I.

That's weird. DTS tracks always sound louder to me. And an article I read about audio compression said that compression lead to lower volumes.

 

[no. 5]

Emorphien is probably right, it’s a difference in mastering. I have read that DTS mixes are usually louder than Dolby Digital.

 

[mouettus]

how are you connected to your receiver?
Multi-channel input?
HDMI?

Also I think your player is an old one like de BDP-1000 from samsung. I know they had some issues with volume. check the setup options on your player. Also, make sure you've installed the latest firmware.

 

[MDS]

Sometimes the result is slightly louder and sometimes slightly softer but at least with my collection of WAVs and MP3s the difference is so slight you can't hear the difference.

DD and DTS use the same concept as MP3 and should be similar. You don't know if the uncompressed version is the same version that was used to create the compressed version. It may have been dynamically compressed before the encoding to DD/DTS (which would make it louder). So the mastering has a lot to do with whether the compressed version is louder or softer.

 

[darien87]

how are you connected to your receiver?
Multi-channel input?
HDMI?

Also I think your player is an old one like de BDP-1000 from samsung. I know they had some issues with volume. check the setup options on your player. Also, make sure you've installed the latest firmware.

My player is a PS 3 with firmware 1.80, (the latest one Sony has put out). I am going HDMI from the PS 3 to my receiver.