Essential audio recording – part one

Lavalier mic. Photo: courtesy Sennheiser

Watching the videos on companies’ websites, or indeed many of the offerings on YouTube, turns up any number of examples of poor sound recording.

Creative camerawork, animation or effects, and a lively sound track can mask poor sound quality. But for any piece involving dialogue, good quality sound is essential. That includes any piece of journalism.

Capturing high-quality sound is not especially expensive; what it does need is attention to detail, and an understanding of how location sound will work in the final piece. For journalists or film-makers who are relatively new to location sound production, this two-part feature will offer a few essentials pointers, both on equipment, and on techniques.

The location

Arrive at the venue in good time and listen to the environment. Select a place where the ambient sound either works with, or at least will not disrupt, the story. A piece about traffic might benefit from some traffic noise, but not at the expense of being able to hear the interviewee. If in doubt, aim for a quiet location and add “atmos” sound later (see below).

Avoid intrusive background noise, such as air conditioning, lifts, slamming doors, PA announcements, and background music – which might be subject to copyright anyway. Tell people you are recording, and ask everyone involved to turn phones off (not just on silent, due to RF interference on the microphones).

The interview set up

Pick a spot that sounds neutral. Avoid either the dead centre of a room or a corner, due to echoes. Windows are never great for sound, even if they provide good visual backdrops. Soft furnishings – sofas, curtains, carpets – will deaden echoes and unwanted sounds. Areas with hard floors and furnishings, such as bars and hallways, can be very tricky for sound recordists. Standard meeting rooms, with large boardroom tables, are not great either.

A video piece can get away with slightly worse sound than an audio-only piece, but not that much. If it suits the piece, have the subject standing up: this gives more control over mic positioning (and can help them project their voice). Sometimes the only way to avoid background noise is to bring the mic in close, even if this means having it in shot.

“Close mic” techniques, coupled with turning recording levels down slightly, will mask a lot of background noise. Lavalier or clip mics are best here for video, as they are not too intrusive in shot. For audio-only pieces, though, a handheld mic gives more control and usually better rejection of unwanted sound. Either way, remember to check sound levels on headphones before recording.

Avoid a camera’s built in sound

Part two of this feature will look at specific recording tools. For now, here is one piece of kit to avoid: the camera or camcorder’s built-in mic. Unless the recording environment is exceptionally quiet, and the room is either very “dead” acoustically (such as a studio), built-in mics will only give a “home video” feel to the audio. Some pro and semi-pro cameras (such as Sony’s NEX-VG20) have better than average mics, but they are no substitute for an external mic.

If all else fails, and there is nothing else to hand, bring the camera in close, set the mic to the most directional setting (NOT surround sound, on a consumer camcorder), and turn off auto focus if possible. Find the most acoustically flat environment and it can work – but it is a risk.

Record some background noise

Recording “atmos” or wildtrack sound is essential to a polished production. This has three uses:

  • to add effects or a sense of location to otherwise neutral recorded audio, for example re-recorded questions or voiceovers recorded in a studio;
  • to provide a “noise print” for audio editing or correction software, such as Adobe Audition, to make it easier to remove unwanted sounds, such as as AC noise;
  • to provide background audio similar to the main soundtrack, to fade in and out behind studio links, questions, or even idents.

It is often easier to record specific sound effects: a car braking, a plane taking off, the noise of a busy office or trading floor, as atmos with as clean as possible interview footage, and add it in later, than to hope that the right sound effect happens at exactly the right time during an interview.

This third use of wildtrack sound is also worth trying for audio-only interviews, including over the phone or Skype. A noisy Skype link into a studio can be made much easier to listen to, if the remote end of the call fades up behind the studio questions, rather than cutting from one audio source to another.

Check all sound kit, and check again

Given the importance of sound in most productions, it is worth checking and rechecking all settings and kit. If the picture fails, there is always the option of cutaways or B roll, but not for sound. Make sure sound recording kit is set to the same sample rates and bit depth as the video recording requires, and that levels are correct on each device.

Ideally, record a slate (or if not, clap) at the start AND end of each piece, and monitor throughout on headphones. If this is not possible, because of being on camera, ask someone to assist. And check back both on-camera and off-camera sound before allowing the guest to leave.

Part two of this article will look at microphones and part three on other equipment and accessories for recording audio.