Creating 2.0 surround

[Xoanon]

Does anyone know how I can mix a 5.1 mix into a 2.0 surround mix in Audition? Do I need to bring the six channels into multitrack, and do something to the surround channels, e.g. something to do with the phase or panning?

I cant seem to find anything that tells you how to do this.

[unclebud]

Do you have 6 wav files to mix down? If so add them indivually to multitrack and pan if you want and then select mixdown in the menu. Most of the information will be in the front left and right channels so keep them the highest in volume.
Or just use the front left and right channels for stereo.

[Xoanon]

I have six files, yes.

I am going to be converting to AC3 Pro Logic and want to have it so the track is 2.0 surround. The centre, FL and FR will play at the front (of course) and Id like the surrounds to be come out of the surround speakers when I playback in Pro Logic.

[unclebud]

You'll need an encoder for something more then 2.0 stereo.
If your receiver has Dolby Digital or something similiar you might as well just use the reciever for the surround effects.

[guns1inger]

You are bettor off encoding as 5.1 AC3 and letting the play down the downmixing for you. Otherwise, all you can do is encode it as 2.0 channel AC3 and hope your ProLogic mixes it the way you want to. 5.1 AC3 is your best bet.

[Xoanon]

I have a DTS file in 5.1 and I only wish to listen to that. I wish to have a 2.0 surround track and a DTS option.

There IS a way to do thepanning in Audition, I just wish I knew how.

[unclebud]

Panning is just a matter of right clicking on the "pan0" area in the base section for the wave file in multitrack view.

[Xoanon]

That only positions it left or right, correct? I need to put it so that it plays from the surrounds when I encode it to AC3 and play thru my Dolby decoder.

[unclebud]

Audition 1.5 dosen't have AC-3 encoding only stereo. Not sure about Audition 2.0.
Like gunslinger said if you want AC-3 sound just take your DTS track and author with it if you can.

[Xoanon]

You misunderstand Im outputting to a WAV with the matrixed surround info encoded, to reauthor as an AC3 later.

[unclebud]

Can you author with this 6 channel wav file? If so your authoring software may be able to create an AC-3 audio from it.

[Xoanon]

You mean bring all six waves into Sonic Soft Encode (my app) and then output to a AC3 2.0 ? Dont think it works like that.

[unclebud]

So Sonic Soft Encode only accepts 2 wavs to create 5.1 sound?
I'd just take the front left and right channels into Sonic and see if that sounds OK.

[Xoanon]

No, you bring in each mono wave for each channel.

I dont want to not encode the surrodes, information will be missed. Theres a panning feature in Audition, Im sure, to do this kind of thing.

[unclebud]

Audition will write mono files, it' s just up to you to pick each side of a stereo track indivudally and save it to wav.
If you can see all of the channels in multitrack mode select one of the stereo (if they are stereo) tracks and highlight only one side of the stereo wave file and save as a single wave file.
Does this make sense? This should do what you are asking for. If not please explain exactly what you see when the surround track is in Audition.

[Xoanon]

I have six mono files:

FL, FR, C, LS, RS, LFE

This is not about encoding anything; I want to use the in-built panning option (wherever that is) to position the LS and RS waves to be decoded to the satellite speakers after encoding to AC3.

Im going to downmix all to a 2.0 stereo wave (with the LS and RS tracks matrixed encoded) to then convert to AC3.

I dunno how else to say it.

[guns1inger]

You cannot mix a dolby pro logic matrix this way. Your surround information is in the surround channels. Bring all 6 into soft Encode, then encode as 2.0 AC3. You won't miss anything, because Soft Encode will use all the information to create the new channels.

This still will not be as good a mix as letting your player and amp downmix for you.

[unclebud]

If I read you right, your using Sonic Foundry's old Soft Encoder 5.1 sound encoder. All you need to do is add the correct wav file to the track that you want that wav file to be at. No need for Audition, just open Soft Encode and add the files to the correct track for that wave file. Soft Encode will then create a 5.1 AC-3 file for use in most DVD authoring applications. Panning should not be necessary as Soft Encode does that for you.
I've seen this app but never used it but it seems pretty straight forward.
I'm sorry I didn't truly understand what you were looking to do and as Audition dosen't encode AC-3 the panning is unnecessary if you have mono wav files.

[Xoanon]

Ah, so what ur saying is you CAN bring all six channels in and still save as a 2.0 file? Have u tried this? Im sure I did it once and it didnt work.

Remember, Im only doing this to satisfy DVD specs and so I can watch it on my 4:3 mono TV. The DTS will be used for the bigger TV and my home cinema setup!

[Xoanon]

Soft Encode will then create a 5.1 AC-3 file for use in most DVD authoring applications

Again, Im making a matrixed surround 2.0 file, NOT a 5.1 discrete mix.

[guns1inger]

I haven't used Soft Encode for a couple of years because Vegas is much faster and better than soft Encode at doing multi-channel work, but yes, soft encode (at least some versions) do have the ability to output 2.0. The AC3 encoder in Vegas also allows you to tag 2.0 channel with a PL flag.

If you are doing this to watch on a mono TV, why care about the PL mix anyway ? a straight stereo downmix will sound the same form a mono TV.

[Xoanon]

I say mono TV, its basically to watch anywhere I dont have a 5.1 setup. My room, lounge, friend's house, etc. Id be happy with stereo but I want the experience of creating a 2.0 surround mix as Ive never done it.

[unclebud]

Even if you have 5.1 surround it will be mixed-down to stereo or mono automatically. You won't loose any of the sound.

[Xoanon]

As I said, I have a DTS track and I need a Dolby track to go with it. Theres no point having a 5.1 Dolby track for playback on other systems as it wont be used. DTS is the way to go

Its mainly for the experience, really. But I dont think Soft Encode will work with this six waves into 2.0...

[guns1inger]

ffmpeg, from the command line, might. Don't know about ffmpeggui though.

[Xoanon]

I have Soft Encode 1.5 I think.

Is ffmpeg complex?

[Cornucopia]

Ok, here's an ANSWER finally...


This won't give you EXACT Dolby Surround Encoding (without a true encoding plugin), but it'll come mighty close.

Put your 6 waves into Audition.

Pan them Like this:

• LF --> 100%L
  C --> 50%L + 50%R
  RF --> 100%R
  LS -->(50%L + PhaseInverted 50%R) w/ +90º PhaseShift (if you know how to do that, otherwise ignore the phaseshift)
  RS -->(50%R + PhaseInverted 50%L) w/ -90º PhaseShift (same as above)
  LFE --> (Already LowPassFiltered up to ~80Hz) ?? 25%L+25%R

Mix down to a stereo WAVE file (making sure not to overload the mixer itself--bring everything down equally if you have to)

Then, you can convert to AC3 2.0, with the "Dolby Surround Indicated" checked.

Good luck,

Scott

[unclebud]

Boy is my face red, I never saw the Multichannel Encoder in Audition 1.5 before. The surround sound panner works pretty well too. Very nice.

[Xoanon]

Thanks so much, Scott! How do I do the phase shift though, I dont fully understand those bits.

[Cornucopia]

(Static) Phase shifting is where the waveform's SINE wavefronts are shifted by a constant Phase Angle. E.G. a textbook "Sine Wave" will become a "Cosine Wave" when shifted 90º. It's fairly easy to do with analog Electronics, but not so easy to do digitally.
Why?
Because a shift by degrees is related in phase, not in time. Shifting a single frequency like above is equivalent to a delay of the same SINE--but only for that frequency. That means that to duplicate using standard delay techniques, you have to have a frequency-dependent time delay.

Thankfully, there is a VST plugin that can do the same thing easily:
http://www.savioursofsoul.de/Christian/VST/PhaseBug.zip

Like I said, if this is too much extra work, you can try skipping the phase shift.

Scott