Converting Stereo to 5.1
 

Ok so I did a short doc on an xl1s, finished it, looks great etc etc etc. My friend is watching it and asks me "Why isn't your movie 5.1, most docs that I watch are in 5.1?", and I didn't have an answer for him. My 1st thoughts are well.....I didn't record it in 5.1 I guess...

I used an Audio-Technica AT4073A and a Beachtek DXA-6 for phantom power which is just stereo (right?), how would I "up-mix" that to 5.1? Would I have to render the whole 65 min audio track of the film to a .wav and then load it into an expensive audio program then drop it back on my time line as 5.1?

I am using Sony Vegas 8.0b at the moment.

Firstly there are no productions ever recorded in 5.1 and anyone who says that it is is bullshitting, most feature productions are actually recorded mainly in mono with stereo effects recorded seperate to add in audio post.

5.1 is created in post production and involves major audio post and panning matrixing to feed an encoder that then produces the 5.1 encoded signal.

There is not a simple stereo to 5.1 soloution and for small projects you have to ask yourself is is worth the time and effort involved to do 5.1 properly when most people will not have the capabilities to hear it in all its glory.

Also 5.1 may be great for star wars and such effect heavy movies but what audio content on a documentary will benefit from full 5.1? At best you will have stereo effects comming out of the front and rear speakers but all the dialogue will be mono anyway. As for the LFE (sub bass) do you feel that it will be necesary?

There may be a piece of software that can matrix stereo to 5.1 but it will be a huge compromise and may actually make your audio sound worse than just leaving it in stereo.

Here is a VST plug in that will do it:http://www.stevethomson.ca/vi/

If I were you I would be proud that you have made a decent doco with a stereo mix and leave the surround stuff to the guys who have the time and money to do it.

Just FYI - a shotgun like the 4073a, fed to your camera through the Beachtek, isn't stereo even if you're recording it to both channels in the camera. It's dual mono, a single mono signal recorded to two identical tracks. True stereo requires two mics carefully positioned with respect to the sound source so that each one is picking up the sound from its own perspective.

Gary's comments are spot on. Sure you can rerender the soundtrack - you could do it right in Vegas and get a 5.1 track - but what would be the point? You'd end up with sound coming from more speakers but it would all be the same sound. Any surround sound format is based on the idea that different sounds are present in each channel. Give a listen on a proper 5.1 setup to the opening scenes of "Apocalypse Now" where the helicopters are swirling around the listening space, acoustically moving from left to right and back to front. There's a lot more involved in recording and creating that effect than simply sending a quintupled, single-microphone recorded, helicopter noise to 5 speakers, most of which happens in post.

Some of the sound design elements of some features may be recorded in surround - I saw that Baz Lurmann's new film "Australia" was using a SoundField ST350 surround system to record some environmental presence tracks for example - but dialog is still mono, usually centered on the screen, and music is still stereo. There may be speech sent to the surrounds every once in a while for some dramatic purpose but I can't imagine what use that might be in a documentary.

As an aside, there is a very interesting series of Podcasts on iTunes about the filming of "Australia" including a ten minute cast about the film's sound recording and sound design.

I'm with Gary on this with the possible fine point that one can record surround audio during production provided they have the right surround micing that Steve touches on. There are other options, from your own arrays built from multiple mics and recorded to something like a Sound Devices 788T eight track recorder, to something like the one of the holophone systems. : : H O L O P H O N E : :

Regards,

Ty Ford

Its a brave man that trys to record and monitor 5.1 in the field, its bad enough getting my head around an AMS Neve DFC console in the dub suite never mind out in the cold wilderness of on set.

I know nothing about surround sound, but I have a question going back to the first post.

How would someone know something is not 5.1 or it is? Is this a case of the posters sound coming out of only two speakers, but there are more speakers in the system?

If this is the case, isn't is possible to get the same stereo sound to come out of all the speakers (or at least the front and rear ones), thus giving the impression to the speaker owner that they are getting their money's worth for the setup?

On DVDs that can be played back in stereo or in surround sound, isn't it sometimes just a matter of getting the sound to come out of all the speakers instead of just two... with no consideration of real surround sound?

I don't know, I'm just asking.

Jack I suppose you are right but as Ty said real 5.1 surround has things panning around sources and spot FX assigned to the LFE (sub bass).

It can be bodged much the same as most HD material here in the UK is just upscaled digi beta but true 5.1 is an art to create and monitor corectly.

I've been helping out a local doco guy who is doing a shoot on sushi. He and his partners used the Holophone along with a Zaxcom Fusion recorder to get surround sound at a fish market in Tokyo. I haven't heard but a small part of the results, but it's sweet. Of course for people like myself who don't have a 5.1 system to playback on, it's all simply lost on me. ;)


Wayne

Thanks for all the info guys, my doc has a bunch of musical acts in it so it would be pretty cool to do it in 5.1. I will check out all your recommendations on the plug-ins. Even if I don't do it with this project its great to have all this info. Thanks again!

Jack, my friend has a surround system and when he puts a DVD in he always check to see what audio options he has.

I'm guessing that the fish market in Tokyo isn't just A fish market, but THE main wholesale fish market at Tsukiji. Fantastic place and an absolute bedlam. Might be worth the price of a 5.1 system just to hear it all in surround sound!

Here's a link to a Sound on Sound review of the Schoeps VST plug-in for processing surround sound mic-ed with a figure 8 and two cardioids.

http://www.ibs.org.uk/public/lineupa...le_MS_Tool.pdf

And the link to the plug-in is

http://www.schoeps.de/dmsplugin.html

Jim,

Thanks for that. The Schoeps software makes me wish I had a TDM system. Not enough to BUY one, but enough to want one. Oh, and the 5.1 or 7.1 monitoring system too.

Regards,

Ty Ford

Ty,

I downloaded the Win VST version last night.

I have the right capsules, but would have to add one mic amp (Xmas is coming!!!) to have the right setup - or almost the right setup as it would probably be better with the side address cardioids than the front address ones - but I think a little improvisation will do the trick.

Don't really have a 5.1 monitor setup, but could probably cobble one up from the pile of miscellaneous components I have around here that I should have gotten rid of 20 years ago.

Hey all, Don't lose sight of the fact that 5.1 can't be made in post but must be planned prior to the shoot. The reason that DVD's have 5.1 is that the fx are pre planned. Explosions etc. Car chase scenes and other type action that is planned to lend it's aural experience to the video experience.

If you shot a doc and want to come in after the fact and try to pan mono sounds, it's just going to be forcing it. Now your music on the other hand, if captured discretely vs a stereo mix, you could pan that easily to 5.1.

Jeff

the thing that got my attention in this post was when someone mentioned the wholesale fish market at Tsukiji in Tokyo. Damn but that would be superb in 5.1 as it's an absolute madhouse with sounds moving all around in all directions. I used to have an office just down the street from the market and often stopped in for breakfast at one of the little restaurants tucked in among the madness.

There are some good 3D applications (Lightwave, Maya, Cinema 4D, etc) that let you attach sound files to objects moving in 3D space - they even calculate the Doppler effect. Making up some effects in one of these and generating the surround sound might do a nice job of adding effects in post, but I'd seriously love to hear something like the Tsukiji market recorded live in surround.

But your point is absolutely right on - planning, planning, planning!

[QUOTE=Steve House;964807] Give a listen on a proper 5.1 setup to the opening scenes of "Apocalypse Now" where the helicopters are swirling around the listening space, acoustically moving from left to right and back to front. There's a lot more involved in recording and creating that effect than simply sending a quintupled, single-microphone recorded, helicopter noise to 5 speakers, most of which happens in post.

If I remember correctly, Apocalypse Now was recorded on location by Simon Kaye, who used a mono Nagra 4.2!

PS I don't seem to have got the hang of getting quotes from previous posts in that nice blue box. Sorry about that.
Nick