[Skylinestar]

Play a movie (any 5.1 or 7.1 movie) at -10dB master volume and then play a music (any stereo audio file or cd) at the same -10dB. The music always sounds louder than movie. I think -20dB music is as loud as -10dB movie.

Any reason why? Is it because of the way all music are mastered? Or is it just me?

 

[nograveconcern]

Is it because of the way all music are mastered?

Yes. The dynamics on recorded popular music are compressed more than movies. The term is crest factor. A quality classical recording will be much closer to a movie.

 

[JHAz]

Yep. Those of us that are human hear sound as kind of an average, so however loud the oudest half second is become irelevant to how loud the track is - - what's the average?). For nearly ever, recorded music has been limited in terms of big dynamic swings (a solo bass guitar is 10 dB louder for half a cycle or so - say 1/20th of a second - than the beginning of the sustain part of the note, which fairly quicly drops off, too- - you can't waste the ten times power between the leading edge and the sustain in any system that has dynamic limits of less than say 80 dB between noise floor and peak). A vinyl record just doesn't really have the dynamic range to "waste" on millisecond long dynamic peaks, so limiting those was part of mastering music decades ago - - essentially as soon as it was possible.

You can google loudness wars, or look at Bob Katz's website as easily as I can, and draw your own conclusions. There's a somewhat indefinable point where dynamic compression kills music. But up to that point, it's nearly impossible to distinguish without an non-dynamically limited version of the exact same mix (go find me an unsquashed version of CSNY's Carry On or Woodstock, let alone recent stuff). And once the folks doing the original recording become willing to compress individual tracks to the point that they sound different (of course the piano in Lady Madonna is an example of hyper compression used as an artistic device - - I promise the piano sounded nothing like that in the room when Paul played it) then compression at the mastering stage becomes, potentially, the least offensive of the dynamic changes. Steely Dan's two against nature is, IIRC, at least 6 dB quieter, on average, than Sting's Brand New Day, which came out roughly at the same time. Neither sounds squashed to my ears, frankly, leading me to believe that at the mastering stage, a real effort was made not to create a "merely loud (on average)" disc. Both artists assumed that their listeners could figure out what to do with their volume controls. BUT, I wonder what the Sting album would sound like if the tracks were not compressed enough to allow the final master to sound untampered with. We will never know. It's still at least a decent record.

 

[JHAz]

On a slightly different tack, ("come about!") movies are mastered quite differently from music, and have a lot more dynamic range than typical pop music, although classical recordings (and even some jazz, and certainly some of the audiophile recording folks in all genres) still preserve something close to full dynamic range.

While there are no rules for music, for movies, at least at the theatrical stage, everybody should be exactly the same loudness at "reference level" regardless of system, assuming they are calibrated properly. In music, no such concept as calibration applies. Indeed, we inherited a tendency to put levels as loud as possible (minimizes the noise level in analog recording and, frankly, takes advantage of the often nice sounding distortions that occur when you push certain tape recording devices past their linear limits). Until the last few years, the sound on our DVDs and BDs was the same as the sound for the theatrical releases, so if you could identify "reference level" in your system, you could either listen that loud or know how far you departed from it. More recently, remastering for home release has become popular, so we can never hear, or figure out, what the director/producer/sound dudes and dudettes intended to be heard in a movie theater when we play our DVDs/BDs. Frankly, handled conservatively, remastering might well be a good thing. But I kinda miss the days when I could know what the "real" mix was . . . .