These are my personal notes and reference for field recordings. I researched and wrote those in preparation for a trip to some neolithic sites and caves in Ireland with the goal of making recordings there and using them on my upcoming album.
Table of contents
A short intro to field recordings
Field recording refers to all audio recordings performed outside of a controlled studio environment. But it’s also a lot more than that. Field recordings are commonly used as foley in movies or for sound effects in games and other medias, or made for research and scientific purposes, but the use and practice i’m more interested in is one that was pioneered in the 1940’s with music concrète and grew in popularity during the 70’s: field recordings as an art form and for use in music and other forms of art.
When approached through an artistic lens, field recordings become a way to take an imprint of a space or a landscape, to record its acoustic ecology . Not unlike a landscape painter or photographer, a recordist can create an image of a landscape and capture the ambience created by the land and it’s living inhabithants, it’s weather filtered through the artistic choices made with microphone placement, length of recording, mixing and futher processing of the sound.
More recently, interesting interesctions between field recording and other fields of study have been cropping up like archaeoacoustics which is interested in the sonic qualities of archeological sites and the experimental recreation of pre-historic soundscapes. This is usually done in a scientific context with precise measuring and sound emitting devices but I find it really interesting to approach as an artist as part of a creative exploration of the layers of history imbued in a landscape.
A great little video on different musicians and their approach of field recordings
Here are some contemporary musicians working with field recordings:
Techniques
Field recording techniques refer to the different arrangements and placement of microphones in relation to each other and to the sound that is captured in order to achieve different effects in the final recording.
Single microphone
The simplest way to do field recording is using a single microphone, be it a directional or omnidirectional one. This is usefull when trying to capture more precise sounds without necessarily having a lot of the ambient noise coming in the recording.
X/Y
X/Y is the most commonly used recording technique, it involves a matched pair of omnidirectional microphones spaced a couple inches apart. It aims recreate the way our ears pick up sounds and simulate a stereo space by the delay by which a sound gets to one microphone versus the other.
M/S
One of the disadvantages of the X/Y technique is that there is no way to adjust the wideness of the recording acter the fact, the M/S approach allows that. In this arrangement a directional microphone is combined with an omnidirectional (or bidirectional) microphone allowing to focus the recording on a specific area but to also record the overall soundscape and then mix these two sources at varying levels after the fact.
ORTF
The capsules of the microphones are placed 17 cm apart and at a 110 degree angle between each other.
Other techniques
Along with these techniques, new approaches and experimental microphones are more and more used for field recordings. These include stuff like hydrophones (designed to record under water), parabolic microphones (allowing to focus on a very precise point), contact microphones (which are attached directly to a surface), EMF microphones (which record electro-magnetic fields) and geophone (microphone that captures vibrations in material and soil).
Equipment
Starting a field recording practice does not require any specific equipemtn other than a recording device equiped with a microphone. A phone works perfectly well for that purpose. It becomes interesting to get more sensitive microphones and microphones who can capture a wider stereo image of a place if one is interested in recording more subtle or spatial sounds. At the end of the day, the act of going out onto the field, listening actively and recording is much more important than which gear is used for it.
Microphones
Microphones come in different types and sizes for different applications. For field recording the most desired quality of a microphone is it’s sensitivity, in order to be able to capture the tiniest details of a soundscape. For that reason condenser microphones are the go to.
But even in condenser microphones there is a wide array of potential microphones to choose from. Knowing the kind of sound and for which final application you’re recording them can help narrow down that selection. For immersive soundscapes with a very wide stereo field, a pair of omnidirectional microphones or even a single omnidirectional microphone is a great choice. They allow to capture sounds from all around the microphone and if using a pair of them, place them more clearly in the stereo field.
Recorders
The improvements brought to the quality of a recording by the preamps and the recording device itself versus the microphones is almost negligeable. Using high quality microphones with a cheap recorder will yield a way better result than recording with cheap microphones on an expensive recorder.
Power
A large enough and reliable power source is a must have for field recording, especially if you’re trying to record long multi-hour soundscapes and ambiences. Battery banks are a good option, they usually have one or more usb output that can power the recorder for many hours. The microphones themselves are usually powered by phantom power coming from the recorder if they are condenser types.
Accessories
Some useful accessories to include to a field recording kit:
Wind protection
Wind protection takes the form of foam or fur covers that goes over microphone and protects them from gusts of wind which can create a lot of noise and clipping in a recording.
Handle / tripod / monopod
Basically a support for the microphones allowing them to be held securely in a fixed location or moved around without disturbing them and creating additional noise. Tripod and monopods can also be extended to reach things that would otherwise be hard to record.
Headphones
Used to monitor the sound recorded into the recorder, it’s especially useful when setting up levels initially. It’s also great to be able to hear some of the more subtle sounds being recorded amplified through headphones, it can lead to the discovery of interesting sound that would otherwise have been hard to notice.
Recording Settings
Bit depth
Depending on your recorder you’ll be presented with 2 or 3 different bit depth options when configuring a recording: 16, 24 or 32 bits. What this essentially represents is how much dynamic range (or nuance between levels of volume) the recorder is going to pick up and record. A higher bit depth will give more dB of dynamic range which is gonna allow for quiter and louder sounds to be recorded without the quiet ones being lost in the noise floor or the loud ones clipping.
Levels
Data storage
Most recorders have the option of recording directly into a SD card which is great because SD cards with larger capacity are available now and take very little space to store and bring to a location.
Average recording times for different SD card sizes at 24bit:
- 2 GB - 4 hours
- 32 GB - 64 hours
As a common rule, one track of 24 bit 48kHz is about half a gigabyte per hour.