Surround sound mixing for DVD releases

[FP]

When mixing surround for a DVD release, is it necessary to include both DTS and Dolby 5.1 mixes on the DVD?  Must a licensing fee be paid if using either of these technologies for a commercial release?  Is a standard stereo mix also necessary, or is it derived from the surround mix by the DVD player?

I know all DVD players include Dolby 5.1 decoding ability, and newer ones include DTS decoding.

[Ravi]

Most 5.1 DVDs have only the Dolby Digital track.  If DTS is on the disc, it must also have a DD track (5.1, stereo, whatever) or a PCM track, since DTS can not be downmixed to stereo like DD 5.1.  Licensing fees have to be paid to the respective companies.

[Ghostboy]

I know that DVD Studio Pro comes with Dolby 5.1 mixing software...it's pretty easy to use if you still have all your original audio source files and feel like spending the time to do a remix. And it doesn't cost a thing...

[Ravi]

I know that DVD Studio Pro comes with Dolby 5.1 mixing software...it's pretty easy to use if you still have all your original audio source files and feel like spending the time to do a remix. And it doesn't cost a thing...

I've messed with the demo version of Sound Forge, and you can do sound mixes in anything up to 5.1.  You simply put your original files in the appropriate channels.  I can't remember if it allows you to add reverb.  Has anyone here made a short movie with 5.1 mixing in mind (recording ambient noises, recording music in 4-track, etc.)?

[FP]

In addition to asking here, I looked around quite a bit more.

It appears that in some instances there is a pretty steep charge to incorporate Dolby, but ONLY if you display the logo on your product.  That explains the large number of DVDs bearing a "5.1 SURROUND" blurb on the package, with no official Dolby logo.  It's unclear to me if DTS requires a fee.

Ideally, I'd like to do only a single mix, in 5.1.  Dolby looks lke the most convenient method, since DVD players mix the 5.1 into stereo on non-surround-equipped systems.  I think.

I've been editing in VEGAS, and it has an easy to use 5.1 bus that feeds an AC-3 Dolby surround encoder, so the software won't be a problem for mixing Dolby surround.  For DTS encoding, it could be - the only products I found are expensive.  The Surcode DTS encoder is almost $2000.  So, even though DTS can sometimes sound a little better than Dolby 5.1, I'll probably go with Dolby.

There are tons of 'gotcha' technical considerations that complicate the process of mixing surround.  Balance of channels, LFE usage, stuff like that.  A confusing mystery that time and further reading will explain (I hope) is how to mix for the LFE - Should the main channels be rolled off below 120 hz?  Should the LFE mix merely be the low-frequency content spiliing from the main channels, or an entirely different track?  Mixing tips from various sources suggest mixing the LFE 10db down.  5+ channels is way more than 2 and half times as complex to mix than 2 channels.  I suppose I'll be burning expensive piles of test DVDs.

Still learning - any corrections or clarifications are welcome.

[TheVoiceOfNick]

This is a great topic!  I haven't done much mixing of 5.1 for my own movies, but i've been experimenting with remixing my original music to 5.1 from their original source tracks.  A technique i've been using a lot is to leave the original non-bass-specific tracks alone as far as EQing, since rolling off their natural bass will distort the rest of the sound from that instrument.  Then I mix the bass-specific tracks to the LFE channel.  Depending on whether I was going for a bass with some mid-range bite to it or not, I might copy the bass track that I mixed to the LFE channel, roll off the bass (keeping only the midrange), and mixing that to the front right and left channels.

This is music specific, but might help you in mixing your own film project.

[FP]

Finding a matched set of 5.1 monitoring speakers is a little frustrating.  There are very few choices available for a reasonable price.  Assembling a monitoring solution from 5 speakers and a subwoofer introduces a few new problems and is also expensive.

[Link]

Anybody know any good websites about mixing surround, or just sound in general?  I'm getting pretty interested.

[FP]

Very interesting article about proofing surround mixes:

http://www.modernrecording.com/articles/2000/apr/cd-ac3.shtml