FIELD RECORDING EQUIPMENT
(This entire document may be printed out)

OVERVIEW

Recording birds, frogs, mammals, insects and other natural sounds can be very challenging and rewarding. The proper selection of field recording equipment will help you make the most out of every recording opportunity and will probably save you time and money in the long run. Equipment choices are very limited due to the specialized requirements of natural sound recording work. Issues surrounding the choices have to do with quality, specific application, durability, ease of operation and last, but certainly not least, the cost. Formats suitable for use in natural sound recording include cassette, open-reel and digital, specifically, the R-DAT system. Suitable microphone systems include the shotgun and the parabolic reflector. The following sections provide details on the options available to the field recordist based on our in-house testing and extensive field experience.

RECORDERS (CASSETTE)

At the inexpensive end of the spectrum is the cassette recorder which is probably the device used by most people for recording birds and natural sounds. Among the cassette recorders we tested that are appropriate for natural sound recording are three machines manufactured by the Sony Corporation and two machines manufactured by the Marantz Corporation.

Sony offers one monaural machine, the TCM-5000EV ($479.00) and two stereo machines, the WM-D6 ($410.00) and the TC-D5ProII ($1,125.00).

The TCM-5000EV mono machine features a third head which is a playback/monitor head. This feature allows the recording to be monitored as it is being created which can assist the user in determining the quality of the recording. The recorder has a somewhat limited high frequency response which falls off rapidly above 10.0 kHz. The electronic design of the recorder dictates the use of Type I tape only. It also offers a good built-in playback speaker. Input/output connectors utilized are 3.5 mm mini-jacks which are not very durable for field use. The response time of the VU meter is quite slow which makes it highly inaccurate for most natural sound recording work.

The TC-D5ProII stereo machine offers considerably better high frequency response which is usable up to roughly 15.5 kHz. The recorder incorporates Dolby noise reduction and has the ability to record on cassette Types I and II. This unit also has better VU meters, an additional peak level indicator light and a small internal monitor speaker. Input connections are made via professional 3-pin XLR style connectors while output connections are RCA phono pin jacks. This machine is a two-head version which does not permit off-tape monitoring while recording.

The WM-D6, also known as the Walkman Pro recorder, is a very small stereo two-head machine that does not permit off-tape monitoring while recording. The recorder accommodates tape Types I, II & IV. It also offers Dolby noise reduction, but does not incorporate a playback speaker. Metering is accomplished via a small multi-segment bar-graph display and is reasonably accurate. Input/output connections are made via 3.5 mm stereo mini-jacks.

The Marantz Corporation offers a monaural machine, the PMD-222 ($415.00) and a stereo machine, the PMD-430 ($522.00).

The PMD-222 mono recorder features a third head which is a playback/monitor head. This allows the recording to be monitored as it is being created which can assist the user in determining the quality of the recording. Tape types I, II & IV can be used with this machine. The recorder also includes a reasonably good VU meter and a peak level indicator light. A professional 3-pin XLR style connector is used on the microphone input and the output connections are made via RCA phono pin jacks. High frequency response is usable up to about 14.5 kHz. This unit also includes an internal playback speaker.

The PMD-430 is a stereo machine that features a third head which is a playback/monitor head. This allows the recording to be monitored as it is being created which can assist the user in determining the quality of the recording. The recorder is equipped with reasonably good VU meters and a peak level indicator light. The ability to record on all three tape types is offered, as well as Dolby and DBX noise reduction. Input connectors are 1/4" phone jacks and output connectors are RCA phono pin jacks. The recorder has a usable high frequency response up to about 15.0 kHz.

The choice between the Sony and the Marantz stereo machines is difficult. The Sony's are very well built and based on our own extensive experience, are very durable in the field. The Marantz 430, although not quite as durable does provide off-tape monitoring via the third head. This distinct advantage provides the recordist the ability to detect recording problems as they occur. The choice of a monaural recorder is much easier. The Marantz PMD-222 performs (records) far better than the Sony TCM-5000EV, however, if the recorder is to be used for serious playback work the user will probably find that the Marantz speaker is not adequate for the task. One must consider adding an external powered speaker such as the Radio Shack model 277-1008 to equal what the Sony TCM-5000EV's speaker can provide.

When evaluating various models there are certain capabilities to consider. One of the most important features to look for is a manual record level control. The automatic level control (ALC) that is found on many portable cassette recorders is very handy for dictation but is totally ineffective for recording natural sounds. Machines that support Type II or Type IV tape will also do a better job than machines that can only support Type I tape. Type II & IV tapes offer better high-frequency response, lower distortion and better signal-to-noise ratios. Noise reduction systems, such as Dolby or DBX, although a benefit for music and voice recordings, will not work well for recording natural sounds. While these systems certainly will reduce tape hiss, they can also add distortion, breathing, pumping and limit the amplitude of higher frequencies of many bird sounds. If you require the ability to play back sounds in the field, you will want to consider a machine that offers a built-in speaker. The decision between stereo and mono is governed by the uses you have for your recordings. For most bird recording work, stereo is an unnecessary complication. However, if you are interested in recording ambient environmental sounds, or want the ability to discern individuals that might be calling simultaneously, then a stereo machine is preferred.

The open-reel recorder is still the choice of the seasoned professional field recordist. With few exceptions, most of the recordings used on our Peterson field guides are made with open-reel recorders. The advantages are durability, fidelity, long battery life, total immunity to humidity related problems and accuracy. The disadvantages are generally weight, higher cost and frequent tape changes. Portable audio open-reel recorders that are suitable for natural sound recording work were only manufactured by three companies, Nagra, Uher and Stellavox. Of these, only the Nagra and Stellavox are still currently available. Nagra offers a monaural machine (Nagra 4.2) that costs about $6,500.00 and a stereo machine (Nagra IV-S) that costs about $14,000.00. Stellavox offers the SP-9 for about $5,000.00-$7,000.00 depending on head block configuration. Good used machines can often be found at substantial savings. Our experience has shown that the Nagra is the most durable tape recorder that one can purchase. They simply do not fail. The Laboratory has 15-year old Nagra's that are still in regular daily service. For our organization and many others, it is actually the least expensive machine to own. While the initial cost is very high, the cost per year over the life span of the recorder is lower than with any other machine.

The R-DAT (rotary head-digital audio tape) format is very similar in design to a VCR (video cassette recorder) only much smaller. It uses an R-DAT standard cassette tape which measures 2 7/8" x 2 1/16" x 3/8". A variety of lengths are available which permit continuous recording or playback for up to two hours. This recording system offers very low distortion levels and is immune to speed errors, tape noise (hiss) and non-linear frequency anomalies (within its usable bandwidth).

Portable R-DAT recorders are small and relatively lightweight making them very easy to carry around in the field. Features include real-time tape counters, the ability to stamp the current date and time on the tape automatically (available on certain models only) and a built-in indexing system which allows the operator to mark and quickly access the starting points of up to 99 selections. Recently introduced models also offer low frequency filters, 48 volt phantom powering for microphones and incorporate some of the quietest microphone preamps available.

Although it appears from the above information that R-DAT is the answer to all of our field recording problems and needs, there are problems and pitfalls that one should consider before purchasing an R-DAT machine.

1. Most of the inexpensive digital recorders being sold today do not allow off-tape monitoring (the ability to monitor a recording as it is being created). Read-after-write, or confidence playback heads, are available on some of the more expensive recorders ($2,750.00 and higher) therefore recording problems cannot be detected during the recording process.

Nonetheless, the features of digital field recording systems are simply too great to be ignored.

The price range on currently manufactured portable R-DAT machines is between $750.00 and $3,500.00. Listed below are the units we have field tested.

HHB PDR-1000 Portadat $2,745.00.

This rugged professional machine offers read-after-write capability, date and time stamping, low frequency filters, phantom powering and an internal playback speaker. High esolution backlit metering is provided. Professional 3-pin XLR style connectors are utilized for microphone inputs and RCA phono pin jacks are used for outputs. Digital input and output capabilities are provided.

Tascam DA-P1 $1,500.00.

This is the lowest priced professional recorder built for serious field work. It does not offer read-after-write capabilities or low frequency filters, however, it does provide 48 volt phantom powering for microphones. A good high resolution backlit meter isprovided. Input connectors are professional 3-pin XLR style andRCA phono pin jacks are used for the outputs. Digital input and output capabilities are also provided.

Sony TCD-D10ProII $3,200.00.

This rugged machine does not offer read-after-write capabilities, low frequency filters or phantom power. It does offer excellent backlit metering as well as date and time stamping on the tape. A small internal speaker is also provided. Input connectors are professional 3-pin XLR style and RCA phono pin jacks are used for the outputs. Digital input and output capabilities are provided but require an optional specialized cable assembly.

Sony TCD-D8 $750.00

This small pocket sized recorder is a consumer device that was not designed for regular field use. It does not offer read-after-write capability, low frequency filters or phantom powering.

Input and output connectors are 3.5 mm stereo mini-jacks that are not very robust. Backlit metering and automatic date stamping on tape are provided. No internal speaker is provided so all monitoring must be done via headphones. Digital input and output capabilities are provided but require an optional specialized cable assembly.

Other R-DAT recorders we have used successfully, but are no longer being manufactured are the Panasonic SV-255, Marantz PMD-700, Sony TCD-D7 and the Aiwa HD-S1.

Our field work has revealed that the microphone preamps in many of the machines described above, although very quiet, do not always offer adequate gain under certain distant birdsong recording circumstances. High quality outboard preamps are available from several manufacturers that can help solve this problem. Benchmark Media Systems, Inc. offers their MicMan Jr. which sells for about $425.00. It is a two channel, high gain, low noise preamp that does not include 48 volt phantom power. Audio Services Corporation offers the Aerco MP-2 preamp which sells for about $650.00. This is also a two channel, high gain, low noise preamp complete with 48 volt phantom power capabilities.

Contact: Benchmark Media Systems, Inc. 5925 Court Street, Syracuse, NY 13206.
Phone 315-437-6300, Fax 315-437-8119.

Audio Services Corporation, 10639 Riverside Drive, North Hollywood, CA 91602.
Phone 818-980-9891, Fax 818-980-9911.

The short running time offered by the factory supplied Ni-Cad or Metal Hydride rechargeable batteries, coupled with the memory effect that these types of batteries seem to develop over time can be quite a hassle for the field recordist. A relatively new company is now offering external powering options for almost every make and model of R-DAT recorder being made. They utilize sealed, lead-acid rechargeable batteries which offer much greater running times (4-6 hours per pack depending on machine) and can be recharged over and over without any negative effects. The packages offered typically include two battery packs complete with carry cases, shoulder or belt straps, smart recharger and all necessary interconnecting cables. The up front cost is a little high but over the long haul it is certainly worth every dollar spent.

Contact: ECO Charge, P.O. Box 956, Boulder, CO 80306.
Phone: 800-361-5666, Fax: 303-449-1545

Along with a recorder you will need a microphone. There are two types of microphones that are directional enough for natural sound recording at a distance, the shotgun microphone and the parabolic reflector microphone.

To better understand the relative utility of different microphones and parabolas we have compared their beam-width (angle of acceptance) to the field-of-view of lenses commonly used on 35 mm cameras. This comparison is approximate and assumes that the frequency of interest is around 2500 Hz. If the frequency of the sound is lower, a larger parabola is required for equal performance.

MICROPHONES (SHOTGUN & OMNI-DIRECTIONAL)

There are many brands of high-quality microphones available. We have tested, and are currently using, the Sennheiser line of microphones. They have proven to be extremely durable, exhibit very low self-noise figures, offer high output, and depending on the particular model selected, are almost completely immune to high humidity related problems. A good inexpensive shotgun microphone system for general use is the Sennheiser ME-66/K6/MZW66 combination. The cost of this system is about $470.00. This modular system is the combination of the K6 power unit (requires one AA battery), the ME-66 shotgun microphone capsule and the MZW-66 foam windscreen. An additional feature of this modular system is that the K6 power module can also be fitted with other capsules including the ME-67/MZW-67 which is a slightly longer more directional shotgun capsule with windscreen or the ME-62/MZW-64 omni-directional microphone capsule with windscreen for use within a parabolic reflector or remote micing application.

The top-of-the-line Sennheiser shotgun microphones are the MKH-60 and the MKH-70 with the latter being the longer, more directional of the two. The MKH series microphones offer almost total immunity to high humidity related problems, extremely low self noise and very flat frequency response over the usable bandwidth. Their high sensitivity requires special shockmounting and wind protection to make them suitable for handheld field use. Coupled with a Zeppelin style wind screen and a good shockmount the MKH-60 sells for about $1,850.00 while the MKH-70 sells for about $2,100.00. The high-end omni-directional microphone is the MKH-20 which sells for about $1,200.00. The MKH-20 is an excellent microphone for use in parabolic reflectors, or as a stand-alone unit for remote micing of birds from known song perches. The entire MKH series of microphones require 48 volt phantom power to operate. This 48 volt power can either be supplied by an external power supply, or by the recorder if it is so equipped. External power units available include the Sennheiser MZA-14 which sells for $385.00, the Stewart BPS-1 which sells for $125.00 and the PSC Universal Mic Supply which sells for about $290.00. Both the Sennheiser and the PSC models also include dual position, low frequency filter and signal attenuation switches.

The parabolic reflector system is the combination of a reflector dish, typically between 13" and 36" in diameter, and a microphone. The microphone is positioned in the focal point of the reflector which is the area where all of the collected sound is concentrated. Parabolic reflectors, by design, yield a tremendous increase in sensitivity without any added electronic noise. Microphones suitable for use in parabolic reflectors range in price from $300.00-$1,200.00, with the more expensive units yielding flatter frequency response, improved signal-to-noise ratios and higher signal level capabilities.

Listed below are some of the different reflectors manufactured, complete with description and purchasing sources.

1. The Telinga Pro parabolic reflector is a clear, lightweight 22" reflector available in several models that include integral high quality microphones, or as the Telinga Universal model which is designed to accept other manufacturer's microphones. All of these models offer excellent rejection to handling noises and can be completely disassembled for easy transport.
Contact: Marice Stith Recording Services, 59 Autumn Ridge Circle, Ithaca, NY 14850.
Phone 607-277-5920, Fax 607-277-5942 or E-mail

One of the major problems encountered during field recording is handling noise. This noise is transmitted through the body of the microphone and is recorded along with the primary sound of interest. There are various shockmount systems available that are designed to reduce this interference. An inexpensive and somewhat universal model is the Audio Technica AT-8415 which sells for about $50.00. An alternative to buying a shockmount is to make one yourself. A link to printable plans is provided at the end of this document.

HEADPHONES

The ability to monitor and evaluate the quality of your recordings in the field is absolutely essential. The loudspeaker that is incorporated in the recorder is not adequate because it can only be used in the playback mode. Good quality headphones allow you to monitor the incoming signal while the machine is in the record mode, thereby facilitating proper aiming of the microphone. Another benefit, provided the recorder being used is equipped with a third head, or in the case of a digital recorder a confidence head, is the ability to monitor the quality of the recording as it's being created. If there is a problem with the recorder, microphone or cable, using a pair of headphones will allow you to identify the problem in the field and perhaps rectify it before the recording actually begins, rather than finding out hours, or perhaps days later that your recording was flawed.

The choice of headphones is highly personal as to style, isolation and comfort. They must, however, be an appropriate electronic match to the tape recorder thereby insuring adequate output level. The model selected should also offer some degree of isolation from ambient noises so you can listen accurately to your sound source. A couple of our favorite headphones are the AKG K-240M (high isolation rating) which are priced around $105.00 and the Sennheiser HD-25SP (medium isolation rating) which sell for about $100.00. It is important to note that with the AKG K-240's and Sennheiser HD-25SP's as well as many other cushioned styled headphones, that certain types of insect repellents can over time disintegrate the foam cushion material. This also holds true for the foam material used on many microphone windscreens.

We are often asked to suggest playback speakers that can be coupled to a portable recorder or a compact disc player for census/monitoring field work or as a stimulus in research. For relatively close work (under 100') the Radio Shack model 277-1008 amplified speaker is a good inexpensive ($12.00) choice. It is very small, lightweight and, if not played too loudly, offers reasonably good quality sound for frequencies in the 1.0 kHz-8.0 kHz range. For longer distance and/or lower frequency work, the larger, heavier Mineroff Electronics SME-AFS amplified speaker offers very good sound quality over a usable frequency range from roughly 80.0 Hz-16.0 kHz. This unit sells for about $125.00 and is available from Mineroff Electronics located at 574 Meacham Avenue, Elmont, NY 11003.
Phone 516-775-1370, Fax 516-775-1371.

Often overlooked, yet very important, are the interconnecting cables that couple the microphone to the recorder. The best microphone/recorder combination is only as good as the cable that links them together. Quality cables are a bit more expensive than run-of-the-mill style, however, they will generally last longer and perform better. Some manufacturers offer cables that are extremely flexible, even in very low temperature environments. Cable flexibility helps lower handling noise, reduces stress and strain on machine connectors and is easier to coil when recording the session is complete. Consider carrying a spare cable set; it is cheap insurance. Quality cables manufactured by the Canare Cable Company are model L-4E5C StarQuad (lightweight) and model L-4E6S StarQuad (heavy duty). The Belden Cable Company offers the Optima-Hi-Definition Quad and Belden Brilliance Quad. The Canare models offer slightly better flexibility than the Belden versions, however, the Belden models will withstand more rugged field abuse due to their heavier outer jackets.

Cassette machines are especially prone to speed variation problems. These variations can occur from tape to tape or even within any given tape. The age of the recorder, calibration, temperature and the quality of the shell that houses the tape all factor into the speed accuracy issue. If your recordings are to be used for any kind of scientific analysis work knowing the exact speed is a must, as tape speed directly affects how accurately the signals recorded can be replayed on other equipment. An essential tool to help solve this issue is the pitch pipe or tuning fork. If a known pitch, e.g. A-440, is recorded every so often along the tape, it will be possible at a later time to adjust the playback speed of the recorder to match the original recording. Pitch pipes or tuning forks are available from most music stores and are not very expensive.

Audio recorders are delicate precision devices, especially the digital versions. Using a high quality field case for your recorder can prolong its useful life and also help insure its reliability. Dirt, dust and moisture can raise havoc with the internal mechanisms of these machines greatly reducing motor and bearing life and creating excess drag coefficients on other moving assemblies. This can lead to premature mechanical failure or other recording problems.

The Porta-Brace Company manufactures high quality rugged field cases which we use on every piece of recording gear we own. They are constructed with heavy weight, padded, Cordura nylon material. Easy access to connectors is provided by flaps that are held shut with Velcro material. Areas over switch panels and meters are covered with a clear, yet flexible plastic material. Shoulder straps are over-designed for maximum comfort on even the heaviest recorders. Extra compartments are usually provided for spare cables, tape, etc. The cases are not waterproof, however, they are water repellant. Additional padding helps provide extra protection to the recorder in the event the machine should fall or be dropped during field use.
Contact: Porta-Brace, K&H Products, Ltd.,Box 246, North Bennington, VT 05257.
Phone 802-442-8171, Fax 802-442-9118

READING LIST

Since it is impossible to cover all of the factors that should be considered when choosing a recording system or method of using said equipment, we have included a reading list of books and articles which can be very helpful. Some of the books are out-of-print, but your local library or book shop may be able to help.

1. "Techniques for Audio Recording Vocalizations of Tropical Birds," Gregory F. Budney and Robert W. Grotke, in Ornithological Monographs, Volume 48, 1997

(Also available in Spanish translation: "Técnicas para la Grabación de las Vocalizaciones de las Aves Tropicales.")

1. The Science of Sound, Thomas D. Rossing, Addison-Wesley Publishing Company, 1982, Reading, Massachusetts
-covers acoustic theory and science.

2. Practical Recording Techniques, Bruce & Jenny Bartlett, Mix Bookshelf 1992, 6400 Hollis Street, Emeryville, CA 94608
Phone 800-233-9604, Fax 510-923-0369, E-mail
-a very good all around reference for the beginner or moderately experienced recordist. Descriptions of the recording process, types of microphones, microphone technique etc. are covered.

WORKSHOP