Consider these 10 audio editing tips to supplement your videos with excellent sound.
It's time to edit your next video masterpiece. You've recorded awesome images and killer sound, and you're ready to spend some quality time with your computer-editing system. In this article, we will review 10 tried-and-true methods to ensure your sound stays first-rate all through the editing process.
Throughout, we'll use Adobe Premiere as a software benchmark. Premiere works on Macs and Windows machines, and is akin to most other nonlinear editing software solutions. Obviously, we can't address every possible hardware/software configuration, so we've concentrated on tips that will help the majority of users.
1 - Capture Clean Audio
When digitizing sound from analog sources follow some simple rules. Having an analog capture card can be a mixed blessing. On one hand, for example, it allows you to fully run your audio through a mixing board or apply signal processing from outboard devices like compressors. On the other hand, you are at the mercy of the card's manufacturers and how much attention they paid to the audio section of their hardware. Even the best analog digitizer cards will pick up noise and interference just being in the presence of microprocessors and power supplies within the computer. More expensive computer audio systems use external digital-to-analog converters so that the audio signal is digitized before it reaches the electronic garbage in the computer. But most of us are stuck with an internal digitizing devices, so we must do what we can to keep the signal as clean as possible on the way into your computer system.
One way to do this is to keep your playback deck (a camcorder in most cases) as far from computer components as possible. This includes your computer monitor and even the camera's power supply. In addition, run your audio cables perpendicular, not parallel to power cords and video cables. If your capture card uses a breakout box, move it as far away from these items as the cable will allow. This will help to keep hum and buzz to a minimum, maintaining the high quality of your recorded audio, at least until its on your hard drive and beyond your control. Using FireWire to capture audio relieves you of these common analog difficulties.
2 - Optimize Audio Levels
To ensure the strongest possible audio, you can maximize your inbound levels using an external mixer or the audio mixer utility in your computer. Some capture card manufacturers even include a utility to set audio levels. Pinnacle's miroVideo series is an excellent example.
By running your audio through an external mixer prior to capture, you can quickly adjust audio levels from take to take. But even with an auxiliary mixer, you'll still need to get friendly with the audio mixer in your computer. Under Windows 95, 98 and 2000, there is a small speaker icon in the System Tray. Double-click on it to access the mixer utility. Using the Properties settings, you can easily select your soundcard (if you have more than one) and adjust recording and playback levels. Verify your recording levels with an audio editing program like Sonic Foundry's Sound Forge or Syntrillium's Cool Edit prior to a capture session.
3 - Equalize It
Once you have your video clips in the computer, you can use Premiere's audio filters to do some audio touch-ups. There are four audio filters that can help refine your audio: Bass & Treble, Equalize, Highpass and Lowpass.
Click on the audio track (once you've dragged it onto the timeline) and choose the Audio tab in the effects pallet. Among the folders in the audio filters pallet you'll discover the Bandpass and EQ folders. In the Bandpass folder are Highpass and Lowpass and the Notch/Hum Filter for zeroing in on annoying electronic noise or other fixed frequency interference. Highpass allows you to set a low-frequency limit; no audio below that frequency will pass through. This is ideal for minimizing the rumble of wind noise. Lowpass does the opposite, inserting a maximum high frequency value; no audio above your setting will pass through. This option is great to minimize hiss and other high-frequency noises. In the EQ folder are Bass & Treble, Equalize and Parametric Equalization. Bass & Treble does just that - emulates simple bass and treble controls like your home or car stereo. Equalize is a more sophisticated tone control tool with seven bands that allow you to zero in on a particular frequency and either boost it or attenuate (lower) it. The Parametric EQ is by far the most versatile but may take a little more time to master. Parametric EQ gives you three bands where you define a center frequency, the bandwidth (frequencies on either side of the center that are effected), and last the Boost/Cut where you raise or lower the selected frequencies. Always choose Setup in the effects controls for a more extensive graphic interface for your audio controls.
4 - Gain-fully Employed
If you're a FireWire user, you cannot adjust audio levels until the clip is in the computer. Premiere gives you the option to change gain on the audio portion of each clip. Right-click on the audio track and choose the Audio options. In this dialogue you can choose audio gain and either select Smart Gain where the software will raise the gain for you or enter a percentage amount that you want to raise the gain on your audio clip.
5 - Sound Before Beauty
You may be in the habit of editing your video images and letting the audio chips fall where they may. For your next edit session, edit the sound first. If you are creating a dialog piece or interview, edit the video so the audio is as smooth and consistent as possible. When you have that in place, use the tricks in your video tool kit -- transitions, stills and alternate footage -- to cover the jump-cuts and other visual nasties that will inevitably occur. It's a different way of editing and may change your entire outlook.
6 - Narration Tips
Most training and product videos require narration to explain what's happening on screen. You can record narration onto a computer and cut out all the stutters, coughs and missed lines, creating a nearly-perfect performance. When recording narration, beg, borrow or rent the best microphone you can get your hands on. Unlike typical video microphones, studio-quality mikes will provide a smooth, natural sound that is easy to control. Be sure to use a windscreen between your narrator and the microphone. Hoop style is preferred, but a foam windscreen will also work well. If possible, record your narration with a compressor/limiter to reduce the difference between loud and soft sounds. Alternatively, you can use a software-based compressor (included in most audio recording programs) like the one included in Premiere.
7 - Add a Little Background
Music, that is. Nothing sets your video's mood like music. Different styles of music can convey sadness, drama, excitement or encouragement. Several companies produce music libraries that you can purchase outright, with no licensing or additional fees. Music Bakery and Sound Ideas are two companies that provide quality music in a wide variety of styles.
You can also make your own background music even if you don't know how to play an instrument. Programs like SmartSound's SONICFIRE and Sonic Foundry's Acid allow you to create unique, appropriate music for your next video. SONICFIRE does this by asking you for a musical style and a target length. Then it assembles prerecorded bits of music to meet your criteria. With Acid, you select sound loops from a library and combine them to create a unique, new musical composition. "Lite" versions of each program are often bundled with video capture cards and even CD burners.
8 - Sweeten and Spice
In addition to background music, your video could also benefit from a few sound effects. Not the whooshes and clunks they use on the home-video shows, but some carefully selected effects that help tell your story. Let's assume you need a law enforcement feel for a specific segment, but don't have any appropriate footage. Simply combine a siren sound-effect with some simulated police-radio talk and you have an instant solution. You can also use sound effects to add to an existing soundscape. The sound of waves crashing on the beach and some seagulls will transform your simple footage into an exotic beach.
9 - Listen in Context
It's easy to get wrapped up in your video production and lose perspective. Once you're happy with the sound of your video project, record it onto a VHS tape and play it on the worst TV you can find. This will get you out of your comfortable editing suite and give you a good idea of what your audience will actually see and hear. Listen carefully and make corrections based on your observations. If the narration is too soft, boost the level - if the music is too loud, turn it down. Remember your target audience and mix for them.
10 - Output at the Right Level
Regardless of your editing system or master tape, your audience will probably see your finished project on VHS tape. When dubbing your final cut to VHS, make sure the audio recording level is as high as possible without distortion. Your viewers will thank you.
Most of these tips require no additional expense, just some careful attention to the audio portion of your video. Try them on your next production and listen to the sound sparkle.