Surround Sound Question

Are you a sound engineer, or are you just wingin' it? Seems there are two jobs everybody knows. Their own job..., and audio. Honestly, if you want a good surround sound mix, send it to an audio professional.

My short answer is that you can probably do everything in FCP--no need to use
Soundtrack Pro, especially since you said your stereo mix in FCP is already "beautiful".
Congrats!

Assuming that you are doing a 5.1 mix, the basic idea is that your front three channels
are for something like a normal stereo mix, and the rear two channels are ambience,
like reverb and crowd noise. The .1 channel, i.e. LFE, should ONLY be used for special effects.
(In the playback hardware, the subwoofer will automatically combine the LFE track and the bass
from each of the other 5 speakers, but you don't mix normal sub bass to the LFE
channel.)

First of all, you'll need to set up 5.1 monitoring in FCP, using User Prefs : Audio Outputs. Try this:
http://fcproducer.com/2007/02/export-51-surround-sound-from-final-cut-pro/
Once you have 6 channels set up, make sure your stereo mix is still working OK.

For a music mix, you have the option of sending nothing to the center channel,
or maybe L + R mixed together slightly reduced in volume. It's a question of taste.
If you had a bunch of tracks to mix down you could get fancier, but you don't

For the surround channels, you would hopefully have some air mics in the house.
Maybe your camera tracks would work for this? Or maybe you could assign some
reverb return to those channels only.

The LFE channel is only for stuff like earthquakes and explosions,
so you probably don't need to send anything to it, either.

That means that you should be able to get a decent 5.1 mix using only
four channels of audio mixdown, which might be easier for you since
you only have four channels to start with.

As far as the crowd noise goes, that's trickier. Was it OK in the stereo
mix? Then you should be able to come up with something,
perhaps by using EQ on the camera mics. Or you may have
to fake it with SFX. 🙂

When you've got something that sounds good in 5.1, you'll need to
double-check that it also sounds good in stereo. Playing your DVD
on small laptop speakers might help in this regard.

One thing that might trip you up is the fact that different people
number the six 5.1 channels differently. Typically 1 and 2 are
front, but sometimes surround is 5 and 6, sometimes 3 and 4.
Here's some more info:
http://www.cycling74.com/story/2006/5/29/234743/478

Finally, when you author your DVD, you'll have to send use
Apple Compressor on your six audio channels and encode using
the Dolby Professional 5.1 setting. Then use that encoded file
as your audio asset in DVDSP.

Have fun!
Les

Actually, you want all frequencies under 80Hz mapped to the Subwoofer. In surround sound the layout is as such. Left and right channels are for directional front sound. Center channel is for sound that would normally come from BOTH left and right speakers, like the voices of people standing directly in front of the camera. The rear channels are for sound that is generally out of phase (according to the old Pro Logic blueprint) except that now you can map them in stereo. So a plane flying overhead can go from left to right rear, as well as front. A 20Hz sound wave is just over 10ft long, so it is non-directional, meaning you send ALL of your bass (under 80 for major speaker systems, under 100Hz for satellite speakers) to the sub. It will handle the low end for your fronts as well as your surrounds. You ideally want your crowd to be in the LF, RF, LR, and RR speakers, with the fronts a bit louder to simulate being in the front row of the hall and the rear speakers have the noise that is behind you, the viewer. If you really want to go nuts, adjust the levels depending on the camera angle to simulate switching seats from the front of the hall to the rear when you switch to that wide shot.

Actually, you want all frequencies under 80Hz mapped to the Subwoofer. In surround sound the layout is as such.

Sorry, RedTruck, I have to disagree on this one. The issue is bass management:
http://en.wikipedia.org/wiki/Bass_management

In the early days of 5.1 mixing, people did what you are describing.
There were bass management plug-ins in NLE systems, but that approach is
fundamentally flawed.

In theory, each of the 5 locations receives a full-range sound.
Ideally, each speaker could handle the bass, but for practical reasons,
pretty much every 5.1 system includes the bass management
in the hardware. That's why you generally patch your five channels
to the sub, and then pass through to the individual speakers:
http://www.genelec.com/documents/qsg/GenelecQSLSE.pdf

The problem is: if you do bass management in the mixdown,
like you suggest, then you're doing it twice!! Once in the
mix, and once in the hardware.

So now the best practice is to do it ONCE, in the hardware,
where it makes more sense.

Here's an excellent article on bass management:
http://www.ambisonic.net/bassmgt1.html

Okay. As I have not read what you have posted yet, I will defer to you guys on that one. I am basing my info on the knowledge I had while building and installing high end home theater systems. But that was some time ago, so if technology has become that much better, great. I will read those posts and update myself. Thanks for the re-direct.

*what's the point in editing surround sound if the TV does it for you*

Perfect!