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.
A Clean Capture
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.
Install a Clean Filter
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.
In addition to the zillion audio effects included in most editing packages, many offer the convenience of installing additional effects called plug-ins. These plug-ins are the software equivalent of buying a new piece of specialized audio equipment. Ranging from simple filters and equalizers to more esoteric processing like phasers and vocoders, plug-ins give you recording studio effects on your desktop. The best part is many of these plug-ins are bundled with various audio software you already own. With a little snooping, you can also find a boatload of audio plug-ins for free on the Internet: www.directxfiles.com is a great place to start.
If you edit training or product videos, you’ll likely have to record some narration to compliment what’s on the screen. Before computers revolutionized the video-editing arena, they quietly conquered the audio scene. What used to take thousands of dollars of equipment in a carefully controlled environment is now easily done on virtually any computer made. First, you’ll have to choose an audio editing program – Sonic Foundry’s Sound Forge and Syntrillium’s Cool Edit are perennial favorites – then you can record and edit your narration as easily as you can edit video. Cleaning up narration audio is much simpler than many video edits and you may even get a few new audio plug-ins to share with your video software.
Music and FX
What’s a good video without some background music? Boring. The right music can supply the sonic glue that ties your entire video together. Stylistically, it can change the mood or even appeal to a completely different audience. Music for your video project is available from a variety of sources. Buyout libraries allow you to pay for the music once and use it all you like. Music Bakery, Digital Juice and many other companies offer excellent buyout products. You can also make your own. And don’t forget the sound effects. Not just the comical sproings and bangs, but tasteful, appropriate sound effects like traffic noises or birds chirping. Properly placed with the right volume, these additional elements add to the impact of your video.
One of the worst things that can happen in a video is for the audio to fall out of synchronization with the picture, right? So why on earth would you ever unlink the two? Well, actually, there are many times when this is beneficial. In Premiere, simply right-click on your video track and choose the option to Unlink Audio/Video. Now, you have the ability to trim the in and out points of your audio independent of the video. This offers the potential for some powerful overlapping segments. Or maybe the audio portion of a particular clip or series of clips is disposable. If you’re not going to use it, why go to all the trouble of volume-adjusting or muting the clips? Just delete the audio portion and you won’t have to deal with it.
As little as $50 buys a nice set of media speakers these days. But before you sign off on the audio in your project, consider how your audience will hear the finished product. Rather than the pure power of a home theater or even your subwoofer-enabled computer speakers, many listeners will hear your video through the world’s most callous audio reproduction device – the 3-inch television speaker. Without the benefit of even moderate high or low frequencies, your listener will hear a very different audio picture than you did in the editing suite. Once you have a good mix, take a few minutes to make a VHS copy of the project, then view the tape on the worst TV you can find. Listen for missing or over-emphasized sound, and then make the appropriate adjustments to your project. Often, a few small changes will allow your video to maintain its audio impact, regardless of the playback device.
Sidebar: Your Mileage May Vary
All software is not created equal. While most of the high-end editing packages handle audio with every bell and whistle known to exist, many of the mid to low-priced options handle audio very poorly, if at all. One of the first things to go is a plug-in architecture, followed quickly by the number of audio tracks and specific control of those remaining tracks. While you’re saving your pennies for the latest, greatest, state-of-the-art video editing software, dig a little deeper in the software you already own. Join an online user group or surf the manufacturer’s tech notes. You may find some features you didn’t know existed or a workaround for one of its most challenging shortcomings.