For best results in post, average at -12dB on the camera. Be sure that peaks are not more than -3dB. If your audio is too quiet, you’ll lose resolution/audio quality. If the audio has been recorded too loud, it will be clipped at the camera, and is virtually impossible to repair properly. Best results are obtained from PCM/uncompressed audio that has been recorded at 16-bit, 48 KHz audio. If you’re working with HDV or other compressed audio formats, you’ll likely want to conform to PCM audio before applying filters.

Import the audio to the timeline of your DAW or NLE system. If the file requires equalization, you’ll want to apply any necessary filters prior to applying compression. In most all situations of dialog audio for video, compression is the last process in the chain of filters. Software filters/compressors make it very easy to insert filters in any specific order.

Insert the software compressor on the audio track that you’d like to compress. Having an assortment of compressors/dynamic filters is always a good option, as you’ll be able to find the "sweet sound" that each compressor usually has.

The amount of compression will be determined by a few factors. How much would you like to reduce the dynamic range? How much punch would you like the voice to have? There are likely several presets in your software compressor; you’ll perhaps want to try some of these presets, starting at a reduction of 2:1.

To gain a better understanding of compression, and to control it manually, set the compression amount to 1:1. This means no compression is taking place. Set the threshold to the highest level. Make sure all other "knobs" are set to zero, or default position, thereby nullifying their position.

Set the Attack and Release time controls to a middle level, so that they are half way between all the way off, and all the way on. Set the Compression Ratio to a level of 2:1. This will control the amount of output from the compressor. In the case of 2:1, when the volume increases by 2 dB on input, the output will only be 1 dB louder on output. So, a ratio of 10:1 means that for every 10dB of input level, the output will only increase by 1dB.

Once the Attack, Release and Ratio controls are set, start dialing in the threshold level. The threshold level is what determines the point at which the compression begins. A good starting point for properly recorded dialog is at -12dB. (If the compressor has a "knee" option, be sure to set it to "soft." You might want to monitor/listen to the audio as you dial the threshold down. This will help you understand how audio is passed over and under the threshold.

By adjusting both of these levels, it will let you hear how "fast" the compressor controls the levels and how it releases its control of the levels.

In order to set the amount of compression that is occurring, you’ll need to adjust the ratio control. For voice, it would be somewhat rare to have more than an 8:1 compression ratio, but if you’ve got extremely intense vocal action, such as yelling to speaking levels, as much as 12:1 starting at a higher threshold wouldn’t be terribly unusual. Often times, the lower the threshold means a higher ratio, and a lower ratio would indicate a higher threshold.

By using light compressors on each of the dialog tracks, they’ll tie nicely together when or if you use a compressor on a master output control. Some mixes may require a compressor on all audio tracks, and a compressor on the master output. Be cognizant that a large number of compressors inserted on audio tracks can create a heavy load on the processor, depending on the number of audio clips you have. Consider freezing tracks when you’re satisfied with the sound of the track.

Douglas Spotted Eagle
Managing Producer
Sundance Media Group

Douglas Spotted Eagle, a producer and founder of the Sundance Media Group and VASST Training Series, is the author or co-author of several digital media books, including Digital Video Basics (VASST), HDV: What You NEED to Know (VASST, also available on Amazon.com) and Vegas Editing Workshop (CMP Books). In addition to creating music and media that has earned him a Grammy, DuPont, Peabody, Telly and Nammy award, he’s recorded, edited or produced media that has found its way into more than nine Emmy-nominated productions. He uses the latest technology as part of his daily workflow.

Dynamics (i.e. loudness control) is critical, particularly with the exceptionally wide dynamics that digital audio offers. Because of the range of speech, it’s often difficult to keep loud segments of audio under control while maintaining the more subtle, intimate sounds. Moreover, if the levels between the two ranges are too extreme, it makes the overall mix challenging to finish if there are other elements to the mix. Once you grasp the practice of controlling dynamics of the human voice, you’ll dramatically improve your audio for video productions. Compressors can be inserted to any and all audio events, and often are.

Software Compressor Companies:
www.izotope.com
www.waves.com
www.kjearhus.com

Sundance Media Group
www.vasst.com
P.O. Box 3
Stockton, Utah 84071
Ph. 435.882.8494
info@sundancemediagroup.com