Audio Advice
Many video producers are satisfied to concentrate their post-production efforts on the visual side of the project at hand, leaving the audio chips to fall where they may. That's too bad. High quality audio processing software is plentiful and often bundled free in all but the simplest of video editing packages. So, rather than ignore this important part of your upcoming video project, take a few minutes to familiarize yourself with some of the most common and powerful ways to spice up a video soundtrack.
For those who capture their video through FireWire, the process is a snap. Simply plug in and click the record button. But analog capture is still a way of life for multitudes of video producers. If you fit in the latter category, take heart - there are measures you can take to ensure clean audio during your video capture sessions. First, make sure you have a good, solid audio connection between your video playback device and the audio input on your computer. Some video capture cards have their own audio sections, while others require that you use the sound card in your computer. While most of these connections are standard today, there are a few special cards that require a custom pigtail or other unique connector. Just make sure it's seated properly - especially if you capture video intermittently. Second, keep your audio cables as far away from other devices as possible. Power supplies, video monitors and even the computer itself can create various hums and buzzes. If you must locate your audio cables near these menaces, run the audio wires perpendicular rather than parallel to the noisemakers. That will help to minimize the interference.
Once the audio is inside your computer and on the timeline, it's time to normalize. When normalizing, your software analyzes the overall volume and brings the volume up without clipping. Adobe Premiere calls this Audio Gain or Smart Gain - your software of choice may use another name, but the process is the same. Why normalize? The main reason is to get all your clips playing as close to full volume as possible. This helps them compete with the other audio elements in your project. Another benefit to normalizing is the effect it has on separate takes of the same scene, ensuring they all play at roughly the same level, regardless of how they were recorded.
Filters are all around us. Air filters, coffee filters, oil filters, and don't forget audio filters. That's right, there is a way to remove some of the undesirable elements in your audio too. Audio filters come in three basic types - low pass, high pass and band pass - each does just what its name implies. Low pass filters allow the lower frequencies through and block higher frequencies at a point you specify. This is handy for minimizing hiss and other high frequency noises. High pass filters work in much the same way, only allowing the higher frequencies through while blocking the lower ones. This type of filter is handy for eliminating boomy sounds like wind and background noise along with certain types of hum. Band pass filters work in the middle of the audio spectrum, allowing only those frequencies within a specific range to pass through. Each of these filters is a useful addition to your audio toolbox. Experiment with them on your next project.
A cousin to filters, equalization is much like the tone control on your home or car stereo - boosting and cutting certain ranges of the audio spectrum. This can be as simple as a bass and treble adjustment or as complicated as a 31-band graphic equalizer. But don't let the terminology intimidate you; equalizers are very useful in shaping the sound quality of your production audio. Maybe your talent has a small, thin voice. A properly tuned equalizer can beef up the low end and add some sparkle to the upper frequencies. Whether for audio first-aid or simply for stylistic purposes, adding equalizing your audio clips can make a dramatic difference.
Many video editing programs include a feature that allows you to adjust audio volume continuously throughout a clip. Premiere calls these rubber bands and they are very simple to use. Expand the audio track to the full view and you will see a red line running though the middle of the waveform. Clicking anywhere on the red line creates a handle that you can move up or down to adjust the audio volume. A series of these handles offers a great degree of control and allows you to make spot volume adjustments throughout the length of your video, including professional-sounding fades.


Digital Audio Sampling
Audio For Video: How To Mix Stereo
Introduction to Digital Video Editing: The Guide to Getting Started With Computer Video (DVD)
Sound Success (DVD)
Advanced Editing -- Guide to Advanced Computer Video Editing (DVD)
Audio Compression
Composition 201
Producing a Documentary Part 2
Fix It in Post
Video Glossary of Terms