SOUND

When working on a DV production of some significance (e.g., a feature), the question of how to record sound invariably comes up. Specifically, do you record sound directly into the camera or use a separate audio recorder? Often, the knee-jerk response is to use a separate audio recorder because the quality is better. Is this true, or are you just creating extra work for yourself?

State-Of-The-Art DV Sound

Recall, double system sound involves recording picture and sound separately with a camera and audio recorder; then syncing them up in post-production. Single system sound, on the other hand, involves recording picture and sound together on the same medium. No syncing is required.

Early video cameras left much to be desired in terms of sound, but many professionals used a single system approach anyway, recording directly into the camera. The main reasons were ease of operation and portability of equipment (at that time, video was primarily used for documentaries and news gathering).

Today, many filmmakers still believe that video sound is inferior, but this in not the case. State-of-the-art cameras offer 16 bit digital stereo sound that rivals CD quality! Even 12 bit cameras provide extraordinary audio.

The Argument Against Double System Sound

There are several interesting reasons why it's preferable to record directly into the camera. Taken individually they seem like minor inconveniences, however, as a whole they make a compelling argument against using a double system:

• When recording double system sound, two media files are created rather than one. This results in a more complex workflow in post-production.
  
  

• Picture and sound must be synced prior to editing. This necessitates shuttling, dragging, pasting, etc., which is time consuming. (No, you can't batch capture!)
  
  

• Shuttling video and audio tapes risks damaging them. Protection copies must be made to protect the masters.
  
  

• If a synced shot is somehow corrupted, it must be replaced. This entails resyncing and possibly recapturing picture and sound, depending upon the situation.
  
  

• When recording original sound, XLR connectors are used to insure a noise-free signal flow. This is defeated when sound is transferred to the NLE using the standard mini-jacks found on computers.
  
  

• Since the material will eventually windup together again and quality will essentially be the same, what's the point of recording double system sound to begin with?

Camera vs. Recorder

In most cases, the best approach to capturing DV sound is to record it directly into the camera using a mixer and quality microphones. As usual, mics are placed as close to the subject as possible using the hierarchy of microphone techniques (boom, plant, lavaliere, wireless, etc.). Gain levels are controlled using the mixer rather than the camera, which gives the soundperson room to work. This is accomplished by referencing the camera and mixer to each other.

The main drawback of recording directly into the camera is that the mixer is tied to the camera by a cable, which limits mobility. This is the strength of using double system sound-- no umbilical cord. Picture and sound are referenced to each other with time code, which is used to sync them later. Depending on the production, mobility may be an important factor and it may outweigh the post-production problems caused by double system sound. If this is the case, double system is the way to go. Obviously, your budget and schedule must be factored in as well.

Ultimately, the decision to use double or single system sound is be based on shooting requirements rather than quality differences. In most cases, you'll find that single system sound is faster, less expensive and yields great results.

Micing Techniques

There are four basic mic placements from which all mic setups are built: boom, plant, and lavaliere. This priority is sometimes referred to as the Hierarchy of Microphone Techniques. Let's examine each approach:

Boom - Booming involves mounting the microphone to a boompole, and suspending it in front of the subject for optimal sound pickup. Booming is done by a boom operator. The process is exacting since it involves juggling many variables at once, such as holding the mic as close as possible to the subject, moving the mic from one subject to the next, and keeping the mic out of the picture frame.

The rule of thumb when booming is to get as close as possible to the subject, which is just outside the camera frame line. The further the mic is away from subject, the greater the background noise and echo, so every inch closer improves sound quality. The mic is normally be several inches to a foot over the actors head. Up to two feet may be acceptable depending on the situation.

The rule of thumb when booming is to get as close as possible to the subject-- right outside the camera frame is ideal.

Plant - A plant is any microphone fixed in place. It is used to cover a static subject when it is impractical to use a boom. Plants can be conventional condenser mics or lavalieres. They type of microphone used depends on the situation.

Placement is important because plant mics are effective only if dialogue is directed within their pickup pattern and range. Another important consideration is that the mic be properly hidden (planted). Mics can be hidden just about anywhere: behind, on top, and below props, furniture, and walls. The possibilities are limited only by your imagination. The newer lavs are so small that they can be used in plain sight and go unrecognized as a mic.

Lavaliere - The next approach in the mic hierarchy is the lavaliere. Lavalieres, called lavs for short, are tiny microphones worn on the actor's body, either inside or outside the clothing. Most lavalieres are omnidirectional, which is preferable because they must be mounted at many odd angles depending on the situation.

Wireless - Wireless (radio) mics send the audio signal over the airwaves using a transmitter and receiver. Their main drawback is that they are subject to RF interference, so a wired mic should be used whenever possible. They are helpful when the boom operator cannot get close to the action and it is impractical to run a lav cable. 

This material was adapted from Film School Online!  Filmmaking Website

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