Tuesday, September 23, 2008

Sound Judgement

Several people have been complaining about the quality of the audio in certain DVD releases. The gripes come from people as diverse as the animation director John Kricfalusi in his blog, to my coworkers at the TV station who raise a good point when they ask why "Law & Order" is transmitted in 5.1 Surround. What? Unless the corpses on the coroner's table come back to life as zombies and start taking over New York City, I doubt there's going to be much in the way of Surround "Ooo!" and "Ah!" moments in L&O. Kinda like shooting "Meet the Press" in HD. Unless Tom Brokaw pulls out a light saber and starts dueling with Yoda I don't think HD is going to help.

Anyway, back to the DVD's. Seems some folks are disappointed in the audio quality of certain releases, such as The Three Stooges, Looney Tunes Vols. 1-5, and numerous old Hollywood classics. Even episodes of "Columbo" seem a little flat. Dialogue is hard to hear. The score is way back there. That car explosion damn near took my head off. What gives, you ask? You thought "Digital Remastered" would be better? Well, it ain't necessarily so.

The reason for all of this gets into the arcane area of audio processing sometimes refereed to as Psychoacoustics. No, it's not the name of Alfred Hitchcock's favorite string quartet. It's the study of how we perceive sound. The key word being perceive. It's not about how our ears work, but rather how we hear. You see that pair of priceless microphones perched on your head are connected to nature's perfect preamp, your brain. And your brain has as much to do with - in fact, more to do with how you hear things than your eardrums or Eustachian tube.

Film Sound vs. TV Sound

Our parents watched Larry, Curly, and Moe poke and slap on the big screen in movie theatres via 35 millimeter film, the way the producers intended them to be shown. Along with the big picture, there was the big sound. A full-fidelity soundtrack reproduced the audio content of the movie by way of the theater's speaker system. These sound systems used big amplifiers to drive big speakers with a level of quality that was pretty much unknown even in the record industry. By the 1950's, after the introduction of magnetic tape, the range of soft to loud sounds capable of being reproduced in a film was quite wide. This is what engineers call Dynamic Range, and as the technology improved, sound engineers put this range to use. Dialog was kept down, while extreme noises were brought up to ear-splitting levels. Thus, in theatrical release Road Runner cartoons from about 1955 on, the music remained at about 60%, while the Acme Rocket Car hit the speakers at 90% or more. And the kids loved it.


Most of us living today have only seen The Three Stooges or Bugs Bunny via a very imperfect contraption we in the biz call the consumer grade television receiver. Gone are the days of the Saturday matinee. Baby Boomers, and we Tweeners, grew up watching these little gems through the static and the fuzz as they were transmitted by our local television stations via grainy, faded, splice-riddled reels of 16mm film. This arrangement was filled with compromise, and television engineers knew the limitations. So, certain adjustments were made.

First, consider that the TV broadcaster is restricted by the FCC (or the equivalent government agency in Canada) as to how loud they can broadcast the audio. If Wile E. Coyote's dynamite is too loud, there's going to be hell, and a hefty fine, to pay. But that bomb is going to go off far too quickly for any master control engineer to catch it in time. Second, consider that many of us, including John K, watch television with fairly simple equipment. Thirty foot CinemaScope curved screens became relics to be replaced with the 13-inch Trinitron with a 3-inch mono speaker. No Voice of Theater speaker cabinets in the living room. Believe me, I've tried. The wife put her foot down.

Furthermore, with a few exceptions, advertisers want their commercials to be LOUD. (No. The commercials are not really louder on the air than the show - but they are fed from the network much louder than the show, and that causes the local station's compression to "pump." More on that in a later post.) So, TV stations are under pressure to be LOUD, whether it helps the programs or not. Trust me, the studio audience on "Oprah" doesn't get any more musical when it's pumped up with 30 decibels of gain.

So, electronic solutions are employed. Audio compression - not to be confused with file compression used in the digital world - is inserted into the audio chain to manage the sudden bursts of frenzy, and make everything more or less the same volume level.

As a result, generations of TV viewers have been watching Warner Brothers' cartoons, the Three Stooges, and "The Wizard of Oz" on analog television with the audio compressed, or "optimized," or "squeezed to death," or "turned into AM radio," or whatever phrase you want to use.

Wide, Wide World

Along comes home video. Early VHS tapes weren't much better than broadcast television - in fact, they're worse. But DVD is a format that exceeds the limitations of analog NTSC North American telecasting. And the engineers who master DVD's want the people who've shelled out for home theater systems to get the most bang - and boom, and crash - for their buck. If you hook up your Blue Ray to a Surround system and sit down to watch "Star Wars" in your home theater, the Death Star blowing up better be the loudest thing in the show, by golly. Obi Wan talking to Luke about the Force is supposed to be soft - just like it was in the theater.

And that's the crux of the whole matter. DVD engineers are trying to recreate the movie theater experience. When they master the audio track, they follow the guidelines of the original production notes whenever possible. New films shot these days really aren't "films" anyway, they're shot in an HD video format at 24 frames per second, again to recreate the film experience. Since the "film" is mastered in an HD format anyway, the content is simply downconverted to the NTSC format for DVD release, with the original audio integrity retained - all 100 decibels of it. In the case of old school content shot on film, the engineers don't "ride the gain," but rather expand the dynamic range even more for an even bigger impression on the home theater viewer.

In other words, new "digitally remastered" or "restored" DVD releases are not put out there for the casual TV viewer still getting by with an RCA Colortrack console. You're supposed to run out and buy a plasma and hook up seven speakers to the thing and let Batman blow the freakin' roof off the place. I'm not exactly sure what artistic merits there are to expanding the audio on any of the Three Stooges repertoire. Fortunately, some newer TV's, like my big screen Trinitron, offer an automatic volume control intended to compensate for the wild variations in audio levels from one cable channel to another. The auto volume does a great job of throttling the audio of "over mastered" DVD's, so I never miss an eye gouge or a face slap or a "Nyak, nyak, nyak." Ah. Now that's technology making life better.

No comments: