Audio For Video – Part 3 Audio Production Techniques
By: Hal Robertson
Regardless of how polished your finished video is, nothing can influence your viewer’s mood and acceptance of that video more than a professional soundtrack. In the past, professional audio could only be produced at major recording studios. With the advent of low-cost pro audio tools and computer-based audio production, you now have the power to produce anything the big boys can at a fraction of the price.
In this section we will look at audio production techniques you can use to produce professional soundtracks, narration and sound effects.
Nothing sets the mood for your video like a good musical soundtrack. Watch any movie or television show (even news “magazines”) and you will hear music creating a mood that compliments the images on the screen.
Turn the sound off and most of that feel goes away. I can’t imagine watching the ’80′s Miami Vice without the Jan Hammer soundtrack – it just wouldn’t work. Conversely, the wrong music can do just as much damage. For instance, a Bahamas vacation video would be difficult to watch with polka music in the background. Used properly, music can relax, inspire or excite your viewers – even evoke a response that visuals alone cannot.
In years past, production music was licensed on a “needle-drop” basis. Music was distributed on LP records and the video producer would pay for the use of the music based on how many times it would be used and the number of tape copies (imagine the paperwork for a reorder). Fortunately, today there are many other ways to find suitable, affordable music for your video production. The first way is called “Buyout” music.
This is music that is recorded specifically for independent producers and purchased outright. You are granted unlimited usage of the music for any number of productions – it’s yours forever. Although music quality varies greatly, there are a few companies that produce an excellent product. Music Bakery and Sound Ideas are two high-quality buy-out music suppliers. Buy-out music is typically distributed on CD, complete with several versions of each musical piece. There is usually a full-length version (3-5 minutes), 60 and 30 second versions for advertising, and maybe a 5, 10 or 15 second version as a “stinger”. This also allows you to create a musical “image” for your client by incorporating the same theme in their training videos and commercial advertising.
Another option is MIDI music. MIDI stands for “Musical Instrument Digital Interface” and is the international standard for electronic keyboards and related equipment. A MIDI recording doesn’t actually record the sound, but records information about the notes played – note pitch, volume, duration and sound type (piano, guitar, drums, etc.). Ideally, any music produced in a standard MIDI format can by played back on anyone’s equipment. Reality isn’t quite that perfect, but workarounds are fairly easy. The main advantage to MIDI music is complete control. A MIDI file is typically distributed on floppy disk and loaded into your computer. With the right software, you can actually change instruments, re-mix instrument balance, change key, change tempo and generally slice and dice the music to suit your project. However, there are drawbacks to using MIDI music. First, your MIDI equipment (sound card, synthesizer or sound module) is the final determining factor in the quality of sound. Even though the music was produced on $10,000 worth of equipment, if you play it back on a $50 sound card the quality will suffer proportionally. The other disadvantage is availability. Not many companies are producing “buy-out” MIDI files right now, but they can be found if you look hard enough.
That brings us to the last option – Original Music. In almost every community, there are individuals with boundless musical talent. The right musician with a recording studio or MIDI recording setup can provide you with fresh music, written specifically for your project. Keyboard players are particularly well suited to this task since one keyboard can play many instruments – even function as an entire orchestra if needed. Now you have the power to specify musical style, length and even instrumentation. Of course, this won’t work with just any musician (musical types are notoriously eccentric). However, when it does work, you have the edge by being able to offer “custom” music for your client’s projects. None of this comes without a price – original music is always more expensive than buy-out. Even a 30 second commercial can require 4 musicians, studio time and equipment rental. The advantage is that you have supplied your client with one-of-a-kind music written precisely for them. That may be just the prestige they are looking for.
Narration (also called “voice-over”) is generally used to either tell a story or to reinforce the visuals on the screen. A properly recorded professional announcer will add polish to any video. You can find voice-over talent in a variety of places, but local broadcast facilities are a good starting point. Listen to various radio and TV stations and pick a voice (male or female) that is easy to listen to. You are looking for a voice that compliments the look and feel of your finished video. A Top-40 “hype” announcer will be hard to use on your nursing home video and the classical station DJ probably won’t work on your tractor-pull commercial. When you contact the “voice”, be completely honest and tell them exactly what you are looking for. Some “voices” have an exclusive contract with their employer and cannot take on outside projects. On the other hand, you may be able to work a deal to bring some (or all) of a client’s advertising to the station in exchange for using “the voice” on your production video – who knows?
I prefer to record my voice-overs in a recording studio, simply because they have all the goodies to do the job right and fast. In reality, all you need is a good microphone, a high-quality tape deck and some patience. The de-facto standard microphone for talk-radio and voice recording is the ElectroVoice RE-20. The RE-20 is a very forgiving microphone with a smooth, warm quality. Voices are reproduced with a pleasant, uniform sound that is very nice to listen to. Although the RE-20 sells for several hundred dollars, it is worth the investment if you want to record your own professional voice-overs. That said, I’ll confess to recording narration with almost every kind of microphone imaginable, including a $10 computer mic (it actually worked quite well under the circumstances).
In addition to the microphone there are a few other items needed to record “professional” quality narration. Obviously, you will need something to plug the microphone into. In Part 1, we mentioned the Mackie MS1202 VLZ mixer. This is a high-quality, compact mixer that can accommodate up to 4 microphones and 4 line level sources (tape deck, CD player, computer sound card, etc.). There are other manufacturers, but all Mackie products are built to exacting standards and will take a beating for many years. You will also need something to put your microphone on. Microphone stands can be purchased for as little as $25 at music stores and Radio Shack.
This next item separates the professional recordings from the amateurs – a compressor/limiter. Compressors lessen the difference between the loud and soft passages of your voice-over. This keeps the loud portions from getting too loud and the soft portions from becoming too soft. A limiter is just a compressor set to “limit” sharp peaks to a user-defined maximum level. Properly set, a compressor will add “punch” and “presence” to your narration, helping it be clearly heard above the music and background noise. ART, Alesis and dbx all make simple, inexpensive compressors that produce excellent results.
The final item is a windscreen. To my ears, there is nothing more unprofessional than a voice-over recorded with breath pops and other noises. We mentioned windscreens in Part 2 to help eliminate wind noise and vocal “plosives”. Narrators usually record very close to the microphone, maximizing the potential for popping sounds like “b”, “p” and “t” to make their way into your recording. Windscreens are typically made from open-cell urethane foam, are inexpensive and readily available at Radio Shack and music stores – go buy one!
Part 1 of this series referred to the high quality sound possible with most of today’s video gear. Specifically the Hi-Fi audio track on VHS/S-VHS and the digital audio tracks on the DV and Hi8 formats. Unless you really want to spend $1000-$2000 on a DAT (digital audio tape) deck, you can use the video equipment you already own to record your voice-overs and other audio goodies. You’ll have a real-time counter (handy for editing) and video of the narrator if you want. If you must have a separate audio recorder (and don’t want to spend the big bucks), look into the MiniDisc format. It produces CD quality sound, includes some basic editing features and is reasonably priced ($200-$400).
When recording your voice-over, you will need a quiet location. Back bedrooms and walk-in closets are great for this. These rooms are usually located away from the high-traffic areas of the house and contain materials that will absorb unwanted sounds (clothing and upholstery). The quieter the better. In fact, you should also turn off the air conditioning during your recording sessions as this low-frequency rumble will definitely be on your recording. If it gets too hot (or cold) take a break, turn on the air and go for a walk around the house to clear your head. Alternatively, you can build a temporary “vocal booth” by hanging some thick blankets, comforters or even scrap carpet on the walls. For those wanting something more “permanent”, check out a company called Auralex. They make sound absorbing foam and other items used in recording facilities around the world. Their products are available in many colors, look very professional and are highly cost-effective.
Narrators often have several tricks to keep their voices at peak performance. They range from snake oil to prescription drugs. Here are a few I have seen (and some I have used). First, and most important is proper hydration. Drink lots of clear liquids, preferably water. Although it is nice to have a bottle of water to moisten a dry throat during a recording, proper hydration occurs long before the session. One alternative is Gatorade – specifically “Lemon Ice”. Another popular drink is herbal tea. Hot liquids of any kind will help open your sinuses with steam. I would avoid coffee, though. It is either too hot, too sugary, too creamy or too strong. Some vocal coaches recommend swishing any drink in your mouth to minimize extremes of hot or cold on your throat.
Eucalyptus cough drops are popular for opening the sinuses and clearing congestion (just remember to remove the cough drop before recording to avoid mouth noises). Antihistamines and decongestants can also help clear congestion – just find one that won’t make you groggy and take it only when you absolutely need it (many of these products have the effect of drying your throat too). Milk products are a major no-no. Milk creates thick mucus on the back of the throat that results in much throat clearing and seems to restrict the vocal chords.
Here’s an odd one I have personally tried (with some success) – potato chips! Not Pringles or those new Olestra chips – just plain old, greasy, salty potato chips. They say the grease acts as a lubricant and the salt acts as a mild antiseptic. Also, the chips serve to clear the throat of drainage and other nasties when swallowed. Not sure why, but it seems to work.
These last two narrator tricks are less superstitious and more technical. Many people produce lip smacking sounds as they speak. A quick way around this is to rub on some Carmex lip balm. Not only will it reduce the smacking sounds, it has an aromatic quality that can help clear sinuses. As the “voice” speaks into the microphone, you may find the sound too aggressive or full of distracting mouth sounds (odd pops and gurgles). Simply reposition the microphone so the narrator addresses it at a 45 degree (or greater) angle. You may also try positioning the mic from above the narrator, pointing down at their mouth. You will be surprised at how this will change the character of the sound, hopefully for the better.
When you think of sound effects (or SFX) you probably think of cartoonish whooshes, clunks and bangs – just watch any episode of America’s Funniest Home Videos. When applied properly, sound effects, like music, can be a powerful tool in your video production. SFX are like spices in cooking – they are easy to overuse. Most of the time, they are included in the final mixing stage as “audio sweetening”, to punctuate the visuals. Effects can add drama, comedy or simply strengthen what is already on the tape. I have added applause and other crowd noises to many videos to enhance what was previously recorded (or not recorded).
Sound effects are available on a “buy-out” basis as well, and can be purchased from Music Bakery, Sound Ideas and other suppliers. There are also sound effects collections available on CD-ROM for playback on your computer. Videonics makes a clever device called the “Boing Box”. It contains digital recordings of hundreds of sounds however, the quality is variable and the effects lean toward the comical. Whenever possible, I prefer to record my own. Your camcorder contains a high-quality audio recorder, is portable and battery powered – perfect for recording sound effects. Although there is an art to recording SFX (far beyond the scope of this article) it is possible to achieve professional results with limited equipment. There is also a real satisfaction in creating your effects from scratch.
Not so long ago, I was editing 1/4″ analog audio master recordings with a razor blade and splicing tape. Fortunately, those days are gone forever – now I can use my computer. Virtually every home computer manufactured today (PC or Mac) contains a good quality audio section. Recordings can be made directly into the computer from microphone or line level sources, then edited at will. Even if you don’t use a computer to edit your video, you will marvel at the capabilities offered by computer-based digital audio recording and editing (not to mention the “Undo” feature).
First things first, we must have a “Multimedia” compliant computer. On a Windows 95 machine, we’ll ask for a minimum of a Pentium Processor, 16MB of RAM, 1GB of hard disk storage, a CD-ROM and a 16 bit sound card. Although this isn’t even a minimum system by today’s standards, it will suit our application nicely (my apologies to the Macintosh users, but I spend most of my days with an operating system from Redmond, WA). Additional processor speed, RAM and storage will improve reaction time, but not sound quality. Keep in mind, one (1) minute of CD quality, stereo music will occupy a little over 10MB of storage. Recording in mono cuts that requirement in half.
You should also familiarize yourself with the inputs and outputs on your sound card. Typically, you will find a microphone input, a line-level input, and a line-level output (usually attached to speakers). All these connections will probably be stereo 1/8″ mini-plugs – not the most stable connection, but functional. Most PC’s are packaged with a cheap microphone – some are even built into the monitor or keyboard! Avoid these mics like the plague. They typically hum and buzz due to their proximity to the computer monitor and their sound quality is questionable at best. You will input your professional microphone and music sources through a mixer (as mentioned above) and then into the line-level input. Although you can monitor on your PC speakers, it’s better to plug the line output of the sound card into a variable input on your mixer – that way you can monitor with headphones.
There are many programs available for recording and editing digital audio. Some popular titles are: Sound Forge, Samplitude and Cakewalk. There is even a limited recording utility included with Windows 95. Of these, my all time favorite is a shareware title called Cool Edit ’96. You can download a free trial copy from the Syntrillium web site – full version purchase price is only $50! With a few exceptions, Cool Edit can perform any function of the $300-$500 packages. Using Cool Edit, you can easily edit the length of a piece of background music, fade music in or out smoothly, speed or slow the tempo of the music, even reduce tape hiss. Editing narration is also much easier, allowing you to cut out hesitations, stutters, false starts and lip smacks. There is also a “stretch” function that can squeeze a 32 second spot down to 30 seconds or stretch that 55 second voice-over to exactly 60 seconds – you’ll never notice the difference. You can also raise or lower the pitch of voices, effectively giving you more vocal personas. The possibilities are staggering.
We mentioned MIDI music earlier. If you need to integrate your MIDI music and any combination of digitally recorded content (music, narration or SFX), check out a program called Cakewalk. With Cakewalk, you can seamlessly integrate all the audio elements of your video production. Each instrument or sound is assigned it’s own “track” where you can independently control volume, left-right stereo balance (or “pan”), fade-in, fade-out, looping and many other operations. You can also use Cakewalk to record your MIDI files, digital audio and sound effects – it’s just like having a multi-track recording studio inside your computer. Cakewalk also has the ability to chase-lock to SMPTE time code (through an external box) from a video or audio deck. This opens a whole new world to those editing on linear tape systems, allowing some of the conveniences of non-linear editing on their existing equipment. Cakewalk can be a bit intimidating at first, but if you need this level of control and flexibility, the time spent learning this powerful software is worth the price.
Using a computer and digital audio software, you can produce a polished, professional video soundtrack complete with all the necessary elements. Since all the audio is located on your computer, timings can be rehearsed and fine-tuned, and generation loss (from bouncing audio between tape decks) is eliminated. Using a technique described in Part 1 of this series, you can fly your finished soundtrack onto the video master in one pass. If you edit video in a non-linear environment, save the finished soundtrack as a .WAV file and import it into the timeline of your video software (ala Premiere). You can also use Premiere as a sort of digital multi-track by increasing the number of audio tracks. Break your voice-over into logical chunks (separate .WAV file for each) and place them on the timeline where needed. Using the “rubber bands” on the audio tracks, you can easily raise and lower the music and/or background sounds to accommodate your narration chunks and sound effects. Then be thankful, this function alone requires well over a thousand dollars worth of audio equipment in the linear tape world. br>
HAL ROBERTSON is an 18 year pro-sound veteran and owns Sound Foundation. A consulting/training firm specializing in media production. You may reach him at (417) 782-9601 or E-mail: email@example.com