View Full Version : Mixing 16 tracks for 5.1 DVD


Jeremiah Rickert
January 11th, 2012, 01:57 AM
Hey all. I have done a lot of capturing of live shows, and usually I get a 2 channel mix-down of the board feed and pipe it right into the XLR's on my camera. This time, however, I was given a thumb drive with 32 .wav files on it. (16 tracks x 2 halves of show)

I pulled them into Vegas and the mechanics of 5.1 sound panning are fairly obvious, but I'm wondering what the "philosophy" should be. I feel like there's a big-picture thing that I'm missing. The show was a mix of interviews, skits, and music. My instinct is to throw all the talking forward, the music in the middle/front and the crowd in the rears.

The 16 tracks are really 14, because the last two are mix-downs, but here is the list of what I have:

01. Wireless 1 (Host)
02. Wireless 2 (Co-Host)
03. Wireless 3 (Various)
04. Emcee/Announcer (seated in a theater box stage left)
05. Statler (seated box stage right)
06. Waldorf (seated box stage right)
07. Desk Mic (host on Wireless 1 also had a this mic on his desk)
08. Stage Mic (Front center mic used by individuals and a musician at one point)
09. Room Left (attached to light rack above audience)
10. Room Right (ditto above)
11. Cue Left (Music tracks)
12. Cue Right (Music Tracks)
13. Trumpet Left (Instrument mic)
14. Trumpet Right (Instrument mic)
15. Downmix L
16 Downmix R

Should I downmix some of these together before rendering out the AC-3 file?

I did a quick and dirty mix using stock levels and just moving the panning "dot" where I thought it should go and rendered it out. I burned a Blu-Ray right from the timeline in Vegas and tested it out on my home system. My receiver decoded the DD5.1 just fine, it sounded okay to my ears, but the surrounds were a little soft. THEN we had a cast/crew viewing of the rough-cut and I brought my Blu-Ray player and the disc and connected to through HDMI to the host's TV, but he didn't have a sound system just right into the TV. There was crackling that sounded like clipping coming out of the TV speakers for several spots in the show that I didn't hear in my home test. That's why I think there's some big picture thing that I'm missing.

Any help or advice would be greatly appreciated.

Many thanks!!

JR

Steve House
January 11th, 2012, 04:45 AM
Why do 5.1 at all? None of the tracks you listed appear to contain any material that is actually happening behind the viewer so at first glance it appears the surrounds would be superfluous. A conventional stereo mix for the music with all the dialogue as a mono mix centered between L and R would cover it. If you really do want to go for 5.1, about the only thing going to the surrounds would be the audience. Think about the camera as always looking in the direction of the gaze of a hypothetical viewer sitting 'front row center', turning their head to look directly at the person on stage speaking or performing. When the host speaks, the viewer is looking at him and his voice comes directly from the center of his field of view. The fact the speaker was off to one side of the stage is irrelevant in terms of his location within the viewer's soundscape.

Why's the trumpet given its own mic and why are there two stereo tracks for it? If there's only one trumpet, it's a mono source by definition and should be treated the same way as dialogue, ie, mono centered. If there's a band or orchestra it's really strange that only 1 instrument in it is mic'ed.

Statler? Waldorf? Why the h are they?

Jeremiah Rickert
January 11th, 2012, 08:11 PM
Obviously some things need to be cleared up.

Statler and Waldorf are two hecklers who were seated high above the stage in the theater box (as they would be on the muppets). Their voice sorta comes out of nowhere up and to the left of the audience. Having it directional on the DVD is closer to the live experience in the theater.

The Trumpet L and Trumpet R are actually instrument mics that are used for different portions of the show. They are guitar mics for one number and trumpet/drum mics for another.

Steve House
January 12th, 2012, 05:40 AM
I still stand by my original doubts re using 5.1. If Statler and Waldorf are off camera to the left, pan them to the left channel in a stereo mix. If they're on-camera when speaking, keep them centered. It would be very confusing to SEE them dead center in the field of vision defined by the screen boundaries but HEAR them off to one side or from the rear. Likewise, if you're sitting in the audience looking at the stage, everything is happening in front of you. Nothing from the stage is to the viewer's rear.

Allan Black
January 12th, 2012, 03:56 PM
I agree with Steve here. Years ago we produced annual dealer shows for Ford, IBM, 3M and Qantas, all with quadraphonic sound, and we learned heaps about placing stuff in rear speakers. Very basically, if your viewing audience hears 'info' from behind them, it distracts them from the front and they
instinctively want to turn around*.

If your 5:1 mix sounded Ok to you on your system and the first replay on another system has problems, that could be the tip of the iceberg.

So take your DVD along to more 5:1 replay systems and make notes, stop after half a dozen. If you can't run tests on a few systems,
don't attempt a 5:1 mix, obviously if you plan to sell a lot of discs you don't want people complaining and wanting a refund.

Your 5:1 viewing audience of more than say 3 people won't be seated right where your mixing chair was, and the speaker placement and acoustics
of every replay room will be different.

And when you're mixing, after you hear it a dozen times you'll 'know it' and it becomes easy to lose diction by having vocals too low in level.
Mix on the safer side, I'd put it all at the front L/Center/R and the audience all around, but lower than you might think.

You're getting surround mixing experience and that's all good :)

Cheers.

*One time we had a team from Syd. University turn up to study this effect, they almost drove us crazy.