Friday, May 6, 2011

Equalizing Audio Levels in Soundtrack Pro

A buddy of mine is working on a short film and needs lots and lots of "ambient location soundscapes" (his term :) and a few of the recordings have wildly different volume levels.

For example one recording is a person whispering between bouts of a person yelling a speech and thunderous applause. Yeah, I know; could you get any worse for post-production? Well, I did have a client once ask me if I had a "color filter" and I was like, "Yeah?" because we do but they meant something that turns black and white footage into color. I just told them yes (always say yes) but that it's VERY VERY EXPENSIVE (always say it's prohibitively expensive when you want to say no).

So, not really sure what my friend wanted this little bit of audio to sound like because they didn't either I tossed it into Soundtrack Pro, removed the background hiss/AC Unit/whatever it is via a noise print, and then used the Compressor filter.

It looks like this:

It's under Process >Dynamics I think and what this little HUD does is basically, bring up low levels and bring down high (or loud) levels. 

Set the Limiter Threshold to something like -6 or -3dB (don't forget to tick the blue box to activate this slider), monkey with the Gain so overall it's at a level you like and generally bring up the Compressor Threshold a bit to clear out some background noise.

Now, some audio people are undoubtedly reading this with one eyebrow raised but yes, I know what all this stuff does but this is Quick Fix Post Friday Madness.

See the little play button to the left of the volume slider? To the right of that slider is a preview button of sorts which will toggle the audio playback with and without this filter applied so you can see if you're making things sound worse or better; it's easy to mess with stuff so much and lose track of just how much you've changed things from the original.

Hit Apply to apply.

You'll see all sorts of fun adjustments happening and when I was done with this bit of audio the whispers were loud enough to hear but not overbearing, the applause was now less room rattling and a bit of the background hum was removed as well.

Sometimes on some systems there's a bit of a nasty bug with some of these effects. Occasionally you'll hit playback to see what your changes sound like and the resultant audio will be full volume and screeching from distortion. I don't know why. A few times toggling the play button usually resolves it, I'm told.

No comments: