Search DC to White Light

Saturday, November 10, 2012

Give me an L-F-ing Break

This is a general request.  It goes out to all the folks mixing audio for television.  It's a simple request, too:  Listen to your product before it goes out the door.  I mean, really listen!
 
Eight thousand years ago, when we laid back a final track, we listened to it.  Yeah, yeah, everybody listens to their tracks.  But, at the time, before stereo, MTS, BTSC and all the other acronyms, we listened on the studio monitor, then on a four-inch Quam squaker atop the audio console.  (We also viewed release video on a mono monitor, too, but that’s for another day.)
 
Any number of times the great audio on the JBL or Altec sounded like garbage on the Quam…and far worse than just what the poor response of that midget caused. 
 
Often the problem was the desire to pump a lot of bass into the signal.  Cool idea.  And on a console TV system with some semblance of an audio reproduction system, it sounded pretty good.  But that bass, when pushed through the 5 watt amp to a small speaker suddenly suffered from A) heavy distortion from the amp and B) even worse distortion as the tiny voicecoil, now getting some nice square waves from the amp, bottomed and topped out, taking the midrange with it. 
 
So, you listened on the small speaker and you heard the problems…and you remixed so that folks could actually hear intelligible audio. 
FADE TO BLACK
 
FADE IN
It’s 35 years later.  We’ve jumped over stereo, forgotten about quad and moved into at least 5.1 sound.  And, hurray for the dot-one.  That is if you have the audio system for it.  No, wait.  Even if you do have the system for it, it’s not a hurray.
 
Why, you ask?  No, really, I just heard someone ask why.  
 
The thinking on the creative side is, “Now we have some real audio.  Let’s use it all.”  And the production guys try to give creative what they want.  So when that Hummer is thundering across the salt flat, they mix the LFE’s (the low frequency effects…the dot-one part of 5.1 content) hot – really hot.
 
But, guess what.  After they listen on the studio monitors – in 5.1 and properly adjusted – many apparently don’t listen in other formats.  And, as far as I can tell, no one in the studio is listening through a TV broadcast audio processor…and, get this…I’m revealing a big secret here…all broadcasters are using them.
 
I’m not going to go into a lot of technical detail here.  But let me offer one example…You’ve produced a “smokin’” (hey world, would you stop with that word!) make that “driving” audio track.  Lots of LFE information.  It hits the station’s audio processor.
 
More than likely, that unit is a multiband processor.  If so, depending upon on its settings, it may squash the dynamic range considerably and completely change the ratio of LFE to audio.  And, again, depending upon settings, if there is a “bass coupling” control, that driving bass will upset the reproduced levels of the midrange and high frequencies, usually reducing them considerably.  
 
So you dump in a thunderous series of 40Hz sfz notes and the track pulses wonderfully.  Then, it hits the processor which, when it sees those pulses, lowers the overall gain – and you lose the dialog!
 
Right.  The dot-one tail is wagging the 5 dog.
 
Now, these days, finding good dialog is hard enough.  But then, to have to dig it out of the mud because of the LFE channel, well, that's just not fun.  It means either backing up with the DVR and trying to pick out a few of the words or just changing channels.
 
Then, don’t forget to figure in processing to comply with the CALM Act.  I have earlier posts on that so I won’t rehash it…but that has to be figured in and should be in the monitor chain at the post house.
 
And to go one step further...most home units put out 2 channel stereo, relying on external audio amps to decode to 5.1.  Oh, and that stereo may pass through a set’s processing, offering EQ and even “audio leveling” which, in most cases, is compression.  If the station processing didn’t crunch your track and destroy the ratio of LFE to music and dialog, the receiver’s waiting like a safety in the game you’re watching, to step on your mix with cleats.
 
Now, let’s say the viewer has a nice LED screen – flanked with its internal 2x6” speakers.  They don’t even hear the LFE information.  It may get to the speakers but it may not even generate any sound at the speakers.  So what does the viewer/listener hear?  Nothing but the audio level dropping and, probably, the dialog disappearing.  And, frankly, as a consumer, I don’t particularly like that.
 
Hey creative folks:  try to remember as you mix that pushing the excitement envelope can, in some cases, render the audio unintelligible.  I won’t point fingers but listen critically to just about any one-hour crime drama.  It ain’t pretty.
 
If your finishing house doesn’t have at least some gear to simulate the broadcast transmission process, ask ‘em why they don’t.  And if they do, insist that they use it.  Listen in 5.1, stereo, stereo small speaker, mono small speaker, and 7.1 if you can.  And here’s a tip:  listen on computer speakers, too.  And, shortly, you’ll want to check it on your iPhone’s earbuds.  No  doubt, in short order, multiple mixes will be packaged in the transport stream and be keyed in automatically by the receiver.
 
IFor now, though, if you listen on a number of possible receiving devices, I’ll tell you this:  the audio you leave with won’t be the same as the super-hot mix you had in mind.  But viewers/listeners will get the content.  And wouldn’t that be pleasant.

http://www.orban.com/products/television/8685/



No comments:

Post a Comment