Audio

Audio and Field Recording

Home

Introduction

Field recording means different things to different people.  For some, it may be a primary or adjunct tool for work in disciplines such as cultural studies and anthropology (indigenous peoples, folkways, etc.).  Other recordists collect specific natural or manmade sounds for personal or professional work.  Some use audio captured in the field as a supplemental or integral part of multi- and mixed-media presentations.  And some musicians seek out sounds from outside the studio to blend into musical compositions -- either as components or as the "instruments" and "voices" of an entire composition.

Among these different users, the biggest points in common are that the activity takes place outside the studio, and that good portable equipment is essential.  Following are some observations and suggestions -- many based on my own experience.

Recorders  |  Microphones  |  Headphones  |  Software  |  Samples

 Recorders

In the past, field recording equipment has followed other developments in electronics and audio-- the major difference being the need for portability.  Although you could, in theory, take a phonograph cutting machine into the field (and some did), the appearance of wire and tape recorders really opened up opportunities.  Reel-to-reel tape gave way (though not fully) to cassette recorders (which became more practical as noise reduction technology and better quality tape became available)...And then digital audio came onto the scene.  DAT (digital audio tape), Mini-DAT, MiniDisc are all examples of digital recording systems that use some kind of media that physically moves or rotates past a record or read head.

The most significant change for field recording has been the introduction of high quality stereo digital recorders that use solid state flash memory.  One of the better units is the Edirol R-09HR (by Roland, $300 - $450), which replaced their popular R-09.  Like most of the current wave of small digital recorders, it uses SD/MMC and SDHC flash memory cards.  (A 2GB card gives a recording capability of from 110 minutes (24 bit WAV file sampled at 48 kHz) to 1,993 minutes (83 hours of MP3 files at 128 kbps).  The R-09HR, lying down, has about the same footprint as one of the larger MP3 players, but is two or three times thicker.  The case and tripod shown below make it more convenient to place the recorder when you are using the internal microphones -- and allows you to place the recorder, when using an external microphone, so that you have easy access to the controls.

Edirol also publishes a nice practical recording guide.  Though it features the R-09HR, the basics of recording apply to almost any small digital recorder.



Edirol R-09HR (front)


Edirol R-09HR (rear)

Case and Tripod

Foam Wind Screen

Also:

  • Olympus LS-11 and LS-10:  The LS-10 has developed a pretty loyal following.  The LS-11 is either a slightly better model, or a replacement.  A fair number of the negative reviews online appear to come from people who really don't know much about recording, and/or who don't realize that these isn't like the Olympus dictation and note-taking recorders.  (LS-11 $400, LS-10 $230 - $450)

  • Tascam DR-07:  Tascam's lower end portable recorder.  Read the reviews carefully regarding the quality of the recordings.    ($145 - $280)

  • Tascam DR-100:  A full-featured recorder, it has a unique combination rechargeable Lithium Ion and AA battery power system.  It has four internal microphone heads and will allow you to switch them between stereo cardioid and stereo omnidirectional patterns.  It accommodates XLR microphone imputs and 3.5mm line input and output.  Unfortunately, this recorder won't take the common 3.5mm stereo mic input -- maybe a shortcoming, or maybe an indicator that this recorder is aimed at more serious recordists.  To use this recorder with single point stereo mics you'll need to build or buy a bulky Y adapter.  The recorder is more than twice the size of the Edirol R-09, which sometimes makes it a handful to operate.  ($310 - $600)

  • Zoom H2:  This unit is perhaps not as rugged as some other recorders, but it hosts a fairly wide feature set.  It has four microphone elements -- one pair at 90 degrees (front), and the other at 120 degrees (rear).  You select which spread you want and then record from that side.  You can also use all four mics for 360-degree coverage.  I've seen this recorder used quite successfully recording meetings or for non-broadcast interviews.  Read the reviews carefully regarding the quality of the recordings.  ($150 - $335)

  • Zoom H4n:  This recorder, improved from the earlier H4, has a lot of features that make it almost a portable studio.  You can physically reposition the microphone elements for either 90 degree or 120 degree coverage.  You can also record four tracks.  The down side for many field recordists is that you won't use most of the features and their presence means you'll have to deal with a more complex menu system.  On the other hand, if you do plan on doing music work in addition to field recording this would be an attractive option.  ($300 - $610)

  • Edirol R-44:  This is a jump in quality, features, and size from the recorders above -- it takes four inputs.  The design of the recorder allows you to view the recorder's display and access the most important controls while it is inside a mixer bag or its own case.  The disadvantage of the smaller recorders is that while they are small and easy to hold in your hand -- you end up holding them in your hand or pulling them in and out of a pocket or bag to operate them.  None of the small recorders here are designed for you to use them while they hang from your neck, shoulder, or belt.  (The case for the Edirol R-09 does allow you to attach it to a lanyard.)  Oade Brothers Audio offers upgrades to R-44s that feature improved mic preamps for little more than the normal street price of the recorder.   ($1,000 to $1,100)


Olympus LS-10

Tascam DR-07

Zoom H2

Olympus LS-11

Tascam DR-100

Zoom H4n

Edirol R-44 

Regardless of the brand, I wouldn't buy a recorder that didn't have the following features:

  • Uses AA batteries -- both alkaline (1.5V) and NiMh (1.2V).

  • Uses SD or SDHC removable media (SD/SDHC readers are standard in many laptops/netbooks).

  • Can record .wav and .mp3 formats -- does not rely on proprietary audio formats.

  • Can accept mono and stereo microphones.

There are many other features on the current digital recorders, and the choices and their importance can be a bit overwhelming.  Look at the web sites of reliable online dealers and read the user comments carefully --  remembering that some people who are just starting into audio may have unreasonable expectations (or are just plain clueless).  If you have a friend or colleague who has a digital recorder, ask to give it a try.

Recorders that don't make my list (and why):

  • M-Audio MicroTrack II:  Internal battery.

  • Sony PCM-D-50:  No SD card (only memory stick).  Doesn't record MP3.

  • Tascam DR-1:  Proprietary Lithium Ion battery.

In concept, these digital recorders are the audio equivalent of the point-and-shoot (P&S) digital camera, but with one distinct difference -- described in the next section... 

Microphones

All of the recorders mentioned above come with internal microphones for recording in stereo.  These mics do a pretty good job for general recording.  In fact, even the most compressed (lowest quality) MP3 stereo recording of a meeting will be better than what you get from the typical microcassette recorder.  But the characteristics and specifications of the built-in microphones are not always clearly described and may not be what you need for a particular task.  Additionally, by being attached to the recorder itself, built-in mics make some placement options impossible and tend to pick up handling noise as you operate the controls (though some recorders have wired or wireless remotes).

Here is where these new recorders offer an advantage:  Unlike their conceptual cousins -- the digital P&S camera -- the flash digital recorders let you select what is perhaps the most important component of the recording stream; the microphone (you can't change the lens on your P&S camera).  The circuits and processes in any particular recorder are pretty much a known quantity.  But to achieve specific recording goals you have the option of using the best microphone you can afford -- or can borrow.

Perhaps the most convenient external microphone to use for field recording is a single-point stereo microphone.  That means that at least two microphone heads are installed into/onto a single microphone body and feed audio to the recording device, usually through a single cable and plug.  Prices range from around $50 to over $1,000.  To some extent you get what you pay for, although the most expensive microphones are usually specialist models. 

Most single-point microphones are condenser types.  These require a small current of electricity supplied by a small battery in the microphone, through phantom power from the recorder, or from an external power supply.  Condenser microphones are very sensitive, which helps in many recording situations.  But they are also more sensitive to wind/breath noise, and less expensive models are often poorly isolated from the mechanical noise that can occur when handling the microphone, or even when handling or moving the mic's cords.

Sony ECM-MS957


Tascam TM-ST1


ElectroVoice 635A


Shure SM58

Audio-Technica AT897 

My current primary mic is the Sony ECM-MS957 ($170 to $300).  This microphone uses a different technique for capturing sound.  Rather than using two (theoretically) matched mic capsules, the MS957 has Mid/Side (MS) capsules for stereo panorama.  The Mid capsule picks up monophonic sound while the Side capsule picks up left/right difference sound.  The mic's internal circuitry subtracts and adds the two capsule signals to yield separate left and right channels, and also permits electronic adjustment of the pickup angle.  You can choose 90 degrees for a single sound source or 120 degrees to pick up many sources ranging across the sound field. 

The rotating Mid capsule, which is inside the screen cover, can be pointed through a range of 90 degrees.  This allows the microphone body to be vertically oriented, while the Mid capsule is oriented towards the horizon -- a configuration used by some recordists looking for a fuller sense of ambient sound.  Or the Mid capsule can be oriented towards the front of the microphone in the more conventional configuration.

The MS957 comes with a very handy mic stand that lets the recordist to use the center column as a hand grip.  Although it is supplied with a conventional foam wind sock, I also decided to buy a Rycote Mini Windjammer (Large -- Part #055306, which is not the model that comes up on Rycote's product finder) for additional wind protection.  The MS957 is somewhat sensitive to mechanical noise transmitted up the cable, and the supplied cable has a cloth covering that rubs and provides the noise -- I'll be trying one or two hand-assembled cords to see if that helps.

There is a "junior" version of the MS957 -- the ECM-MS907 ($70 to $100).  This microphone is also a Mid/Side design with 90 and 120 degree selectable coverage.  The Mid element does not rotate.  It has a plastic body and some reviewers note more susceptibility to mechanical noise.  But priced at a little more than 1/3 the cost of the MS957, this could be a good option for many users.  It also might be considered when the recordist expects to encounter dodgy conditions (environmental or social).

Another lower cost alternative stereo mic is the Tascam TM-ST1 ($50 to $100).  This mic is about half the weight of the MS957 and about 2/3 the length.  It is also a Mid/Side mic switchable between 90 and 120 degrees.  For its price range it shows fairly low handling noise.  There is some circuit noise so it wouldn't be a good choice for environmental recordings.  It has a small-footprint weighted desk stand that doubles as a hand grip.

In addition to the single-point stereo condenser microphones, field recordists have other choices in both condenser and dynamic forms:  Shotgun mics (mono and stereo), cardioid, unidirectional, omni directional, binaural, and parabolic.  For example, if you are assembling a more complex audio work, you might want to record general environmental sounds in mono, using an omni directional dynamic mic like the proven, decades-old, and nearly bullet-proof ElectroVoice 635A ($100 to $190).  Other mono or stereo tracks can then be mixed with that background.  For mono voice work the Shure SM58 ($100 to $190) is a cardioid dynamic mic -- a favorite of musicians and as venerable and respected as the EV 635A. 

Shotgun mics are some of the most specialized mics, but are essential when the subject is distant, or when you need to pull sound "out" from the background.  The Audio-Technica AT897 and Rode NTG-2 are popular, moderately priced mics.  They cost about the same and their and characteristics are similar, but there are subtle differences that may be important to some recordists.  With either mic, a good shock mounted pistol grip like the Rode PG2 is a good idea, as well as a good "dead cat" windscreen.  ($250 to $275)

Headphones

Although you can monitor your recording by watching the VU meter or little bars on the recorder's display, that's not really telling you what is being recorded -- only that a bunch of sound is being collected.  (For you photographers, this would be like trying to take a picture with a digital camera using the histogram instead of the viewfinder.)  The goal is to isolate your hearing from the environment so that you hear only the sounds that the microphone and recorder are picking up.  This is useful because you'll know whether or not you "got" what you were trying to get, and also what other sounds you managed to pick up along the way.

Here are some options:

  • Full Enclosure Isolation -- These are the classic big headphones that completely surround your ear and seal up against the sides of your head.  But just because they surround your ear, don't assume that they isolate.  Be prepared to spend some money (The Sennheiser HD 280 Pro and Sony MDR-7506 are good headphones to take a look at -- for around $100 street price) and you'll need to try them on in a noisy environment.  They are somewhat bulky, and you'll stand out in a crowd, but they are easy to put on and take off.

  • Over-Ear and On-Ear Noise Canceling -- Noise canceling headphones work by sampling the ambient noise and providing a 180-degree out-of-phase sound into the earpieces.  Visualize this as a sound wave from the outside encountering a matched sound wave coming the other direction.  They cancel each other out.  The problem is that these systems generate a certain amount of their own noise, so in over-ear types there may be little real advantage over full enclosure isolation headphones.  On-ear noise canceling headphones may be an workable compromise between size and convenience, but they may not be effective enough in some sound environments.  One model to consider is the Sennheiser PXC 300 ($105 - $180).  I have a pair of these and while they are good in the office, on passenger rail, and in a car or bus, they don't have quite the sound cancelling horsepower for airplanes and loud subways.

  • In-Ear Isolation -- These look like the earbuds people wear while listening to their iPods and MP3 players.  The difference is that are designed from the outset to seal the ear canal by means of foam or silicone sleeves, usually available in three sizes to accommodate individual ear canals.  A solid performer is the Shure SCL2 earphones ($75 - $110) which is based on the older E2c.  Shure has both the SCL series and the modular SE series with street prices stretching up to around $270.  In-ear phones allow you to be a little more discreet when you are out and about recording.  The problem is that taking them off and putting them on is a multi-step process, so they work best when you can stay hooked up to your recording rig.  (There are several quality lines of isolation earphones now, but as a rough guide, I wouldn't be interested in sound isolation earphones selling for less than $75.) 

You can be sure that the light weight on-ear headphones and non-isolating in-ear phones will NOT be effective for field recording...There is just too much sound leakage.


Sennheiser HD-280 Pro

Sony MDR-7506

Sennheiser
PXC 300 

Shure SCL2

Software

One of the main advantages of digital recording is the ability to transfer files with no loss of data (the quality of the audio) and to be able to manipulate the audio files on a standard computer.  That computer can be a Windows machine or a Mac -- desktop, laptop, or even some netbooks.  Granted, the speakers on your typical laptop leave a lot to be desired, but you are covered because you're going to be using your headphones anyway (see section above).

Digital Audio Editing:

  • For editing and adjusting the stereo audio from the recorder I use Sound Forge Pro 10.0.  This is sophisticated software with many features -- and a definite learning curve.

  • Another option is Sound Forge Audio Studio -- a trimmed down version but still very capable.  (Both versions of Sound Forge are downloadable as trials, so you can see which you prefer.) 

  • In the shareware world, GoldWave Digital Audio Editor has been around for years and is also well worth a try.  The version as of this writing is 5.55. 

  • Audacity is freeware, and while it may not do everything, it's a good introduction to audio editing and is a fairly compact program.

You may want to make sure that the software will let you edit the "properties" of your audio files.  That way you can keep good notes on the technical details of you recordings.

Audio Samples and a Project

Here are some early recording samples using the Edirol R-09 and a Nady stereo mic, and a link to a multimedia project that used the Edirol R-09 and a Sony ECM-MS957 microphone:

  • Sample 1 -- At the Courthouse Metro Station in Arlington, VA, between trains.  Just before the announcement starts, listen to some footsteps on the left and then they'll clarify as the wheels of a light stroller moves from left to right.  (You'll need to have the volume up fairly high.)

  • Sample 2 -- The arrival and departure of two Metro trains at Courthouse Metro Station.  The first train is inbound to DC and comes from the right.  A little later an outbound train comes in from the left - behind the microphone.  The inbound train holds for a little while, and then both trains leave at about the same time.  In that case you loose some directionality since pretty much the same audio events are happening in both directions.  (The kid you hear at the beginning of this sample is the one who just went by in the stroller on the first sample.)

  • Project 1 -- This will link you to a multimedia project I completed in August, 2006.  The Edirol R-09 was used for the field recording.  There is a complete description of the project off the link.

(Product photographs courtesy of the manufacturers.)

100206