Sound Reasoning: All About Audiotape Recorders

by David Brott
December 1995

When making an effective video, the soundtrack your audience hears is just as important as the images they see. As videomakers, we sometimes concentrate too heavily on video images, and the latest camcorders and VCRs that produce them.

But what about audiotape recorders? An audiotape recorder (ATR) can greatly improve the sound quality of your video production. Follow me into the world of audio for video. Remember: in the world of video, hearing is believing, too.

Mood
Natural sound (or nat sound) consists of the ambience and aural cues that give us a feel for a particular setting. For a train station, nat sound consists of many voices inside a crowded terminal, or the blowing of a train's whistle. The natural sound of a bar is chattering conversation, rattling pint glasses and shallow come-ons. Adding this kind of natural sound to your video is the quickest way to establish the mood of a particular scene.

At the Indianapolis 500 raceway, nat sound would primarily be engine noise and the roar of the crowd. Add some of this nat sound to your racing footage, and it will generate a feeling of excitement--a feeling of being there. Without nat sound, your racing footage would appear unrealistic and artificial.

By definition, videomakers use most nat sound without it being in sync with any visual image. Thus you can record it at any time or place, whether you're shooting video or not. If you find that a particular nat sound will enhance the desired effect your video production, take your ATR on location and record it. Use your imagination and experiment with collecting different ambient sounds.

While your camcorder is a great tool for recording natural sound, you should try collecting and adding nat sound to your video with an audiotape recorder. There are many different audio recorders and formats that work well for capturing natural sound. Most are small, portable units with built-in mikes that allow you to easily capture most nat sounds.

While shooting video, use your camcorder's internal microphone to record a wide selection of sound while targeting specific sounds with an ATR and microphone. Later, mix in the sound effects that you recorded with your ATR and microphone into the general soundtrack. By recording background sounds that take place at your taping locations, an ATR acts as a backup audio tape. In addition, the more audio sources you have available, the more flexibility and choice you have when creating your final video production.

Your camcorder may not pick up unexpected dialog during a family reunion. Or, your camcorder may not capture a specific bird call while recording in the field. An ATR can get these sounds before, during, or after your videotaping.

Be sure and record any ambient sound for at least five or ten minutes. This will offer you more sound to choose from when creating your audio programs. If you find that you need to fill in an audio program with a longer chunk of nat sound than you initially recorded, you can lengthen it by copying it back to back.

Whether you're attending a New Years Eve party or a baseball game, you can pull out your portable ATR and start recording the natural sounds around you. In this way, you'll build yourself a collection of different ambient sounds for use in future video productions. The usefulness of having access to a variety of ambient sounds may surprise you.

During post-production, program audio from your camcorder and the special sound effects and nat sound form the aural foundation of your video production. When editing, mix the ambient sound into your soundtrack with an audio mixer. Watch the relative levels though, you don't want your nat sound to overpower an important narrative or dialog.

Audio FX
Whereas we often use unsychronized nat sound to create a sense of location and ambience, synchronized sound effects help identify and enhance on-screen action. For example, by syncing the sound of footsteps to the character walking in your video, you bring life and realism to the performance. In the same way that you record nat sound, use an ATR to collect these sound effects. ATRs can record a door slamming, an engine revving or the ringing of church bells. Later, you can add this sound to your wedding video.

It's a good idea to record each sound effect more than once. Vary the mike position, and experiment with different angles to achieve the best recording. You'll find that the same sound recorded from a different position or distance will fit better with a particular video scene.

Properly syncing program audio and sound effects to the video in post production is important. Remember the old Godzilla movies? The audio soundtrack never seemed to be in sync with what was happening on the screen. The best way to avoid this type of amateur look is to copy the sound you recorded from your ATR to videotape. Once you've successfully transferred your audio program to videotape, an edit controller--especially one with time code--will help to synchronize your sound with the visual images. Similar to videotape editing, simply select your in and out points according to the audio soundtrack.

With a camcorder-mounted audio mixer, a camcorder and a portable ATR, you can avoid some post production work by actually mixing in music or sound effects from your ATR while you're shooting. Azden's CAM-3 microphone mixer, for example, connects directly to your camcorder's mike input. This small passive unit (which requires no batteries) allows you to combine signals from two external mikes and background music or sound from your ATR.

This sort of arrangement makes it extra crucial that you monitor your audio recording levels with headphones while shooting. This allows you to listen for--and fix--any audio problems.

ATR Formats
Different audio formats allow today's videomaker plenty of flexibility when recording audio for video. Let's take a look at some of the available formats.

• Audiocassette recorders. Portable analog ATRs offer an inexpensive way to record nat sound in the field. Although originally designed for speech only, standard cassette ATRs offer suitable sound quality for amateur video production. Due to transport design and tape stretch, playback and record speeds tend to vary. Because of this, audiocassette recordings are not suitable for lengthy synchronized shots. Audio that's in sync at the beginning of a scene will not remain in sync throughout the scene, even if you transferred the audio to videotape for editing.

  When used in conjunction with an external microphone, an audiocassette ATR is an excellent recorder for background sounds and off-camera dialog. In addition, they are easy to find and relatively inexpensive. A Walkman-style ATR with a headphone jack and a decent external microphone will cost you under $100.

  While you can get by with these small units, slightly larger portable decks produce better sound quality and offer more flexibility. For example, Marantz makes an audiocassette ATR called the PMD-222 ($449). It has three heads, a VU meter, a loudspeaker and a professional XLR external microphone connector. In addition, the PMD-222 offers a telephone line input which allows you to monitor or record telephone interviews and conversations. This application allows you to add live and pre-recorded telephone conversations to your video.

  You can also run external microphones through a mixer and then into the PMD-222. Since this ATR offers a loudspeaker, you can monitor your audio recordings without the need for headphones. The PMD-222 also has RCA outputs which make transferring any pre-recorded audio to videotape easy.

• DAT (Digital Audio Tape). The DAT format has become a popular recording format within the music industry because of its great sound quality. Portable DATs are not much bigger than a microcassette recorder, and have recently become very affordable. In addition, DAT recorders lay down music digitally, which does away with many of the syncing problems that plague analog ATRs. This means that you can use sound or dialog recorded with a DAT audiotape recorder, and it will stay in much tighter sync when editing to your videotape.

  Some portable DAT recorders have high-fidelity, built-in microphones. External microphone inputs are standard. Playback from a DAT recording is so clear, you'll swear its real if you close your eyes.

  Sony offers a portable DAT for $699. The TCD-D7 DAT Walkman is about the size of a standard cassette Walkman. It offers a headphone jack, with mike and line inputs and outputs for use with most sound systems. The DAT format allows for up to two hours of recording time at the SP speed, and four hours at the LP speed. DAT recorders also offer an absolute time counter that's actually written to tape. It doesn't offer the benefits of true time code, but it does allows for consistent, reliable cueing of the tape.

  Some DAT decks will record a time code track, and offer a dedicated time code output. These decks are professional units suitable for serious motion picture recording. In other words, their high cost puts them beyond the means of most consumer videomakers.

• MiniDisc (MD) and Digital Compact Cassette (DCC). These newer digital ATR formats are becoming increasingly popular and affordable. They offer excellent sound quality and compact size. Both record sound using a compression technique that disregards sounds below the threshold of human hearing.

  The Philips portable DCC-170 ($499) is an 18-bit DCC recorder with mike and line-level inputs, a fiber-optic digital output and 14-character display. While DCC uses special digital audio tape, MD uses an optical disk for true random access of any audio on the disk. The MD format's tiny 2.5-inch optical disk holds 74 minutes of sound. Sharp makes a portable MiniDisc recorder called the MD-M11. It includes analog and digital inputs and outputs, and a 21-character track labeling feature. The MD-M11 sells for $800.

  Compact size makes both DCC and MiniDisc ATRs perfect for recording sound in the field. The MiniDisc is rugged, and doesn't suffer from the problems of magnetic tape such as tape stretch and tearing. Whether recording program audio or nat sound, both the DCC and MD formats offer fantastic sound quality.

  Because these formats are digital, they don't suffer from the speed problems of the analog ATRs. Once digital audio has been synced to videotape, it will remain in sync even for long scenes.

The Basics
Don't forget the obvious: an excellent alternative to the ATR is your own camcorder. With its built-in microphone or external mike jack, your camcorder will record sound directly to videotape. This makes it easy to sync the resulting sound to your video elements. Also, the video images you record with your nat sound or effects will give you a visual cue to help you to locate sounds when editing.

And don't forget that stereo VCRs make for great audio recorders. Both VHS and S-VHS formats offer stereo hi-fi tracks that record extremely high-quality sound. Likewise, the AFM and PCM tracks of the 8mm formats also offer sound quality superior to most standard audiocassette decks. Most decks offer line inputs and outputs, as well as the manual record level controls lacking on most camcorders.

Sight and Sound
With an audiotape recorder, you have the ability to capture sound and apply its power to visual images. Sound adds personality and character to video programs, ultimately making them more believable. Maybe your next video purchase should be an audiotape recorder.

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