Is it me or is 5.1 extremely hard to create?

Sykes wrote on 11/1/2011, 10:37 AM
I have been trying to figure out how to divert the sounds when people are talking behind me on my left as I am passing them. Also, what's the difference between Voice and Center? The manual doesn't tell you much other than what they are, well everybody knows that already. The material was recorded in Stereo using an HD cam. The audio from L/R-R/L is awesome, but I wanted to take it to a step further since Sony offers 5.1 option with VMS11.

I did a test copy and duplicated the default audio to all the tracks and panned it from there but it sounded like a car audio system where all the sounds came out at once. I can hear the person from the left rear speaker alright, but at the same time I can also hear it on the front left. I also tried panning using FX and balanced it to the 'Left' but it kind of overpowered the whole thing and made it sound like only the left/rear speaker was working.

This is more like Pro-Logic compared to true 5.1 audio. If that's the case I'd rather keep it at stereo and let my Denon Receiver do the work at its best. I don't know, and I'm kind of lost!

Comments

musicvid10 wrote on 11/1/2011, 11:20 AM
True 5.1 is created using a separate stereo recording from mics at the back of the room (often called "ambient" track) in addition to a stereo recording at the front of the room (which is easily mixed down to create the center channel). I use a Zoom (any model will do) to capture the rear audio.

There are various ways to simulate a rear track using a matrix of the front, perhaps with a bit of reverb added, but you are correct to observe that it is going to sound like Pro Logic, because that's essentially what it is.

My shows use up to four dozen mics (including body mics) that are eventually mixed down to five discrete tracks with Pluraleyes and then panned and mixed in Vegas. You won't get a true room effect by trying to emulate that with a single stereo recording.

A smallish 2-cam 5.1 project using my audio workflow looks like this.
In this one I remember I delayed the center channel a few ms to add some forward depth as well as rear.
Sykes wrote on 11/1/2011, 12:55 PM
Wow! Impressive stuff. So what do you suggest I'd do, since there is a default track in the 'Front' should I copy a track to the 'Rear' channel then pan it a bit to the rear and call it day?
musicvid10 wrote on 11/1/2011, 3:32 PM
If you wanted to emulate a rear surround channel, you could copy the main audio to the rear track, invert one of the stereo channels, delay somewhere 5-15 ms, add a little reverb, and probably bump the bass up a bit. Then you will turn down the rear levels until you can just barely hear it.

And for the Center (front) channel, you could mix the stereo to mono, and drop it -3 to -6dB.

In other words, the most basic center (front) mix is L+R, and L-R for the rear.

That is a really basic approach. I'm sure you could find some plugins that are a bit more sophisticated, such as weighting the rear channel separation, etc.
Sykes wrote on 11/1/2011, 7:58 PM
Thanks, I'll give that a try. Since I couldn't preview anything in 5.1 I'd have to first create a small segment (about 4 min) with various audio track simulations then burn it to a DVD disc and play it back along with my 7.1 receiver. Luckily all had to do was to re-render only the audio files during subsequent testings since the video has already been done. I'll take your expert advise from the above suggestion; sounds more approachable to tweak the Front and Rear tracks since the source was only recorded in Stereo.

By the way, what was this 'Zoom' you were speaking of, is it a 5.1 mic, or software?
musicvid10 wrote on 11/1/2011, 8:56 PM
Zoom is a brand of portable audio recorders, H1, H2, H4 models.