Surround Questions

4thorder wrote on 3/8/2004, 7:34 PM
I am making a slideshow dvd with some ambient music in the background. I want to have both a stereo and 5.1 version of the score with the project and have a couple questions hopefully somebody can help with.

1. Should we mix to 5.1 first then to stereo or vice versa?
2. The audio is being scored in Sonar 3 which is a fairly high end audio mastering program. Would you suggest we do the 5.1 in VV then or find a suitable audio program that does 5.1? I dont think SOnar is the best for this?
3. In a 5.1 mix without vocals or commentary, what should go on the center channel?
4. Are there any established rules or guidelines on mixing 5.1? Such as what instruments should go where etc? I am afraid of getting some confusing mix if I dont use some guidelines. We want to create an enveloping audio experience that is not overwhelming.
5. What program is ideal for authoring a dvd with 2 soundtracks. I am not sold on DVD-A yet.
6. Slightly off topic, but what would be a suitable length of a slideshow dvd project? 30 min? 45 min? I am trying to find an acceptable balance on the right time so it doesn get boring and repetitive.

thanks in advance

4thorder

Comments

riredale wrote on 3/8/2004, 7:50 PM
I will be curious as to how other people on this board answer these questions, as I am just getting involved in surround-sound myself.

Based on what I've read and seen, however, I can offer a little advice. Keep in mind that I'm relatively new to this stuff, too:

(1) DVD players have the ability to downmix a 5.1 track to stereo. In the AC-3 encoder there is the option to add metadata that tells the decoder what to do with various channels (What to do with the center? How about the surrounds?). Nonetheless, I have noticed that, on many Hollywood movies, the user has the option of 5.1 surround OR 2 channel stereo. The implication to me is that the sound mixer guy feels he has more control if he knows that a viewer will only have a stereo setup.

(2) I have no idea.

(3) The center channel is meant to be an anchor point for vocals and commentary. If you don't have any, don't use the center channel. The Lf and Rf channels will create a phantom center, anyway, which of course is the case for 99.99% of all audio.

(4) I have no idea. Maybe that's why sound mixers make a good living. All I can suggest is to try a couple of different mixes, and try them out on focus groups. If they don't like the effect, don't do it.

(5) Supposedly the new version of DVD-A will be able to do multiple audio programs. At present, you could use ReelDVD, Adobe Encore, or a few others that escape me at the moment.

(6) Again, that's what focus groups are for. If it's too long for them, shorten it. My gut feel is that a 10-minute slide show is plenty long. But I really don't know the context. Perhaps an illustrated history of Playboy magazine bunnies would keep my attention for an hour!
Jay Gladwell wrote on 3/8/2004, 8:19 PM
1. Should we mix to 5.1 first then to stereo or vice versa?

If it were me, I wouldn't worry about a stereo version. The DVD player and receiver used by the end-users will take of it.

2. The audio is being scored in Sonar 3 which is a fairly high end audio mastering program. Would you suggest we do the 5.1 in VV then or find a suitable audio program that does 5.1? I dont think SOnar is the best for this?

Let the composer/performer mix the music in whatever program he's most comfortable with. Then do the final 5.1 in Vegas. OR If time permits, play with it. Try both, use the which ever works best.

3. In a 5.1 mix without vocals or commentary, what should go on the center channel?

Nothing if you want, it's your call.

4. Are there any established rules or guidelines on mixing 5.1? Such as what instruments should go where etc? I am afraid of getting some confusing mix if I dont use some guidelines. We want to create an enveloping audio experience that is not overwhelming.

No hard, fast rules that I'm aware as to where instruments should be placed in 5.1. Sounds like you might be worrying about more things than necessary.

5. What program is ideal for authoring a dvd with 2 soundtracks. I am not sold on DVD-A yet.

Again, I'm not clear as to why two versions are necessary. DVD-A works perfectly for everything we've done so far.

6. Slightly off topic, but what would be a suitable length of a slideshow dvd project? 30 min? 45 min? I am trying to find an acceptable balance on the right time so it doesn get boring and repetitive.

Let the material be the determining factor here. You'll know when it's getting boring and it certainly should never be repetitive.

This is just one guy's opinion, based on his experience.

J--
4thorder wrote on 3/8/2004, 8:40 PM
The reason the stereo track is probably needed is for the end user that does not have a receiver and DD5.1 decoding. I am pretty sure then you must have a selction for stereo otherwise you would get static. Perhaps aI am wrong here, but just trying to make sure every situation for the consumer is taken care of.
Spot|DSE wrote on 3/8/2004, 9:04 PM
SONAR can't do 5.1. So, your composer could export 5 separate tracks, you'd import those to Vegas, do your AC3 encode there after creating an LFE track if you want one.
Most DVD players will properly decode/downmix the output of the audio regardless of whether they have a receiver or not. Most systems will correctly mux/downmix to mono directly from the DVD player. This is part of the composite out of most DVD systems that plug into older mono televisions. But it's fairly important that you get the AC3 encode right, so the header data is correctly read, letting the system properly read the metadata that allows for the downmix to stereo or mono.