Choosing Microphones

There's a huge variety of microphones at prices from a few tens to several thousands of pounds, euros or dollars. Almost all are designed for use under controlled conditions in the studio. But field conditions are very different.

Those microphones specifically designed for field use are intended for recording speech, which has a much more limited frequency range than most wild sounds. So selecting the right microphone is one of the most critical tasks for the wild soundscape recordist. Many superb microphones that have made history in the recording studio and most low- to medium-cost live recording microphones are more or less unsuitable for use in the field. Music and speech, for which almost all commercial microphones are designed, are usually much louder than wild sound. For music recording, the microphones are also usually positioned much closer to the sound source, and the recording environment is much more controllable. Draughts, damp and dust are also a much bigger problem out of doors. So the specifications of a microphone designed for conventional commercial recording must be interpreted carefully when deciding whether it's suitable for the field.

When choosing a microphone for wild soundscape recording, the most important parameters to consider are

• technology - dynamic or capacitor

• pickup pattern - omni or directional, and if the latter, how directional

• diaphragm size - small or large

• self noise level

• sensitivity

Other microphone characteristics that matter to the studio and gig recordist but are less important to us include maximum sound pressure level and the precise details of frequency response - provided the microphone covers the whole audio spectrum. But we do have to take physical robustness more seriously than the studio engineer does.

All these parameters except robustness should be published for any microphone of reasonable quality. If they're not, the microphone isn't, whatever the price tag. Beware of subjective descriptions such as "warm", "bright" "dry" and "open" - they're very popular among sound engineers, but they mean absolutely nothing, whatever the price tag of the microphone. Sadly, most reviewers and users think in these woolly terms and don't make use of the published specifications, but we have to as we're usually selecting a microphone for use in conditions for which it was not designed. So it pays to take reviews and public comment on performance with a pinch of salt, check the specs and make your own mind up.

When it comes to robustness, reviews and public comment are the only source of guidance, and it pays to seek out a lot of independent comments. But if you see the same phrases coming up in multiple comments, they're probably manufacturer's or vendor's hype and should be ignored.

One warning though. There's a lot of "grey" equipment with brands that it's difficult or impossible to trace to a specific manufacturer. The same or very similar equipment may be supplied under several different brands. It's mostly made in China, with designs and specifications apparently similar to much more expensive equipment from well-known manufacturers. Many of the well-knowns actually have their microphones made in China, but the big difference between the two is usually quality control. Whereas pretty much all devices from the known brand will comply with the specification, in the case of a "grey" device the specification will be an average or even a best-case, and the tolerances may be very wide. So you might save money by going "grey" but at considerable risk of poorer performance and short life span.