Boost Your Audio in Vegas Pro
by Craig Anderton
Good video deserves good audio, and fortunately, Vegas™ software offers many ways to tweak audio. This often involves strengthening weak, low-level signals so that when the video plays, the viewer doesn't have to rush over and turn up the volume compared to previously-viewed videos. Ideally, you don't want the audio to "shout" or "whisper."
If an audio file's peaks don't reach the maximum available headroom, right-click on the clip, and go Switches > Normalize (Fig. 1). This increases the gain as needed for the peaks to reach the maximum headroom, thus raising the overall level.
If you need to bring up levels further, or the audio is soft except for a few peaks, click on the track's Track FX button to open the noise gate/equalizer/compressor chain. Then, click on the Track Compressor box to show its interface. The compression process lowers high level peaks to reduce the dynamic range, which allows raising the overall average level to make a sound seem louder.
To simplify matters when editing compression settings, check the Auto Gain Compensation box (I often check Smooth Saturation too with voice). The most important parameters are Amount (also called Ratio) and Threshold. Lower Amounts give more transparent compression; higher amounts clamp down harder on peaks, which may sound more "processed." Find the "sweet spot" where the sound is both present and natural.
Threshold sets the level where the compression effect kicks in. Compression affects only peaks above the threshold. Lowering the threshold compresses more of the signal. Again, listen for the sweet spot.
Attack determines how fast the compression leaps into action when the signal exceeds the threshold. A fast attack reacts instantly to peaks but may sound "squashed." A longer attack (5-15ms) lets percussive transients pass through unaffected, promoting a more natural sound.
Ratio and Threshold work together. First, choose the Amount with Threshold = 0. If you just need to control peaks, set Amount to Inf and Attack to 0. For voice, try 5-10 for Amount and 5-15ms for attack.
Second, start lowering the Threshold while looking at the Reduction meter. The red bar shows the current level reduction amount. The numerical to the meter's right shows the maximum compression over time. Set Threshold initially so that the maximum reduction falls between 3 and 6dB. Tweak the compression controls further for the best sound.
Note that if the Input Gain and Output Gain meters go "into the red," there may be distortion. The numbers to each meter's right indicate how much the signal went over. Pull down the Input Gain and/or Output Gain controls to compensate—for example, if the input gain shows the signal is 1dB too "hot," lower the Input Gain control by 1dB.
Experimentation is key, but these guidelines should get you started. Before too long, you'll be a master of compression!
Bio: Author/musician Craig Anderton recently returned from the Summer NAMM convention, where he covered the show for www.harmony-central.com—and used Vegas Pro 64-bit to turn out 73 videos of show highlights in eight days. Photo by Paul Haggard.