Topic: Replacing audio using Vegas 7.0, help please?

[maidencolorado]

First the background.  I filmed a couple of bands using my JVC HDD cammie.  The first one came out sounding pretty good, but the headline act was much louder and thus, distorted on my internal mics (I know, but I'm just getting started and these were the first shows I ever filmed).  I have found an alternate audio source for this show and have contacted the taper to see if it would be OK to use his source with my footage, to which he agreed.

I have Sony Vegas 7.0, and have tried to look for how to do this, but it is Greek to me.  I don't need anyone to hold my hand through the entire process, but if someone could maybe point me in the right direction, that would be greatly appreciated.

Thanks!

[stantheman1976]

My words may make it sound more complicated than it really is but here it goes.

Import both tracks into Vegas.  You'll use your original auido and visual reference.  Bring your new audio track in just below the original audio track.  Go to the beginning of your original audio track and listen for some type of standout event like a cymbal crash stick hits.  If it's just talking that will work too.  With speech the waveform will be quieter and have more nitceable peaks and valleys.  Use a good pair of headphones.  Move the new audio track so it starts to match up with the original.  Find those common events on both audio tracks to help you match them up.  Move the new audio track left or right accordingly until it plays in sync with the original.  When they are both lined up correctly it will sound like one single track when they're played together.  It's really not that hard.  It just takes a little practice to get the hang of things.

One issue you may experience is time drift.  Both sources my be perfectly aligned starting out but will be out of sync later on.  This is caused because the internal mechanisms of different devices might run at slightly different speeds.  So even though you're recording the same thing one device might move a couple milliseconds slower than the other.  With a long single recording it adds up.  

Here's how to remedy that.

First off, go to your options and make sure "Quantize To Frames" is NOT checked.  If this is checked then when you make an adjustment it has to be one complete frame at a time.  If it is unchecked you can make the adjustment as small as you want.

Also, go look in your options and make sure audio resampling is set to highest quality.

Now, go to the end of your new audio track and compare it visually to your original track.  Hopefully you should see some similar points in each and be able to tell how far off they are.  If your original audio track is distorted too bad or AGC was used it may be almost square.  Use your ears in that case.  Play the tracks together and you should be able to tell if your new track is ahead or behind your original.  You may have to adjust the track volume of one or the other to help out.  Just make sure you set the new audio track back to 0 before you render.  Go to the end of the new audio track and hold your mouse cursor right over the end.  Hold down the CTRL key and you'll see the "~" symbol appear.  Keep that CTRL key held down and move your mouse to the left or right.  You are now stretching or shrinking your audio track in real time.  Move it in small increments and listen and compare your two tracks visually each time.  You might have to zoom in and move in extremely small increments to get it right.  Once you're done both tracks should sound like one when played together.  

Now trim off any excess from the beginning or end of your tracks and either delete or mute your original audio track.  Then render to your desired format.

Like I said, it may sound more complicated in writing than it really is.  If you get the chance to do it again and can coordinate with the other taper try to get the camera and external mics physically close and start recording at the same time.  Then make a couple hand claps or other loud, short noises that you can easily distinguish on each source.  Then when you go to sync them together you can find those distinct noises and use them for reference.  This also works great if you're using multiple cameras.

[maidencolorado]

Thank you, worked to perfection.  I actually found what helped me get things lined up right was to have the original audio only from the right side of the headphones while the second audio source from the left (although it wouldn't matter if they were the other way around).  That way, it was very easy for me to tell if they were in synch or not.