Recording audio on location is a great way to document the essence of many urban spaces, add life to podcasts, and improve the quality of video recordings. Modern audio field recording gear is much cheaper, smaller and less obtrusive thanbefore. This is an introduction on how to get good sound outdoors.
For urban field recording, a good choice is a small field recorder using memory cards of the same type as used in digital cameras. Something like a Zoom H2 is a good combination of stereo microphone and recorder all in one that fits in the palm of your hand. This gives you more than 2 hours recording time on a 2GB SD card. Similar field recorders use Compact Flash cards.
The first rule of audio field recording is get close to the subject, particularly if it is dialogue. To record speech the microphone should really be within a couple of metres of the speaker. Any further and the speech will become muddied by ambient noise; and particularly indoors, reflections off hard surfaces can make the speech indistinct if the microphone is much further way from the subject than the nearest wall.
Do not let anyone hold your microphone. It turns vibrations into signals on your recording, and that includes the sound of the muscle tension in the hand. Use a tripod or stand to hold the microphone close to the subject; this will result in a better recording than if someone holds it.
In an indoor setting you can usually turn off unwanted noise sources like a radio or the air-conditioning. Outdoors you can’t usually do that, so you have to move away from noise sources and closer to your subject. The ear is very good at discriminating against extraneous noise, so you have to listen critically, not just for what you want to hear, but also to check there is not too much of what you don’t want to hear. Or record a section and listen to the playback – it is always better to get the cleanest original recording.
Wind noise is often a problem. Most field recorders come with a basic foam windshield – these are typically good for wind speeds up to about 5 mph. Any more and you will have problems with a rumbling sound in your recording – try and move to a less windy location or wait till it dies down. Alternatively shield the mic with a ‘tent’ made of cloth like a T shirt held on a wire frame.
Automatic record level sounds a great idea, but it saps the life from a recording. In a typical city location, as soon as the talent stops talking, automatic record level winds up the levels, boosting things like traffic noise to the same level as the speaker’s voice. When the speaker starts again, the traffic noise is dropped, weakening the continuity of the recording. With digital recording, simply allow plenty of headroom and lift levels in editing.
Recording in a compressed format like mp3 or Windows Media reduces the quality of your recording, making it harder to filter and recompress without distortion.
If you want to record wildlife sounds like birdsong, or very quiet or very loud sounds you will need different techniques. The simple techniques described here will let you record audio for podcasts, phonography and videography under typical field conditions. If the audio will be synchronized to a video recording, a clapper board and spoken take number helps match the recordings up.
These simple techniques will help you capture good audio from outdoor locations, for podcasting, video and documentary purposes.