This is a paper I wrote for a specific time, place and audience. It is very dated. It was written in the late summer of 1987. It was published in Oregon Birds, Vol. 14, No. 1, Spring 1988 pp. 27-33.

BIRD RECORDING EQUIPMENT

David Wickstrom, Supervising Engineer, Library of Natural Sounds, Laboratory of Ornithology, Cornell University, 159 Sapsucker
Woods Road, Ithaca, NY 14850
It is possible to record bird sounds with a wide variety of equipment, much as it is possible b take photographs with a wide variety of equipment. The differences - as one might expect - have to do with quality, durability, ease of operation, and cost.
 

CASSETTE RECORDERS

There are 2 machine formats used in bird recording - cassette and reel-to-reel.

At the inexpensive end of the spectrum is the cassette recorder. It is probably the device used by most people for recording birds. Among cassette machines we have tested, there are 2 by Sony* and 4 by Marantz that are appropriate for recording birds.

Sony offers 1 monaural and 1 stereo recorder. The monaural recorder is the TCM-5000, the stereo is the TCD-5M. The monaural machine has slightly limited high frequency response and does not incorporate Dolby noise reduction. It uses only Type I cassettes. The stereo machine has better response and incorporates Dolby noise reduction as well as the ability to accommodate Type I, II, III, and IV cassettes. Either of these machines will give good service and the choice between them is governed by the need for 2 channels and cost. The stereo unit costs about $150 more.

Marantz offers 2 monaural and 2 stereo recorders. Model numbers for the monaural machines are PMD-201 and -221, for stereo they are PMD-420 and -430. The higher model number recorder in both mono and stereo are 3-head machines and allow monitoring playback as the recording is being made. For wildlife recording this is a very important feature as the level meters are not able to correctly indicate fast sounds that can be distorted.

The choice between the Sony and Marantz stereo machines is difficult. The Sony is very well-built and we have extensive experience with its durability in the field. The Marantz 430 has off-tape monitoring which permits one to listen for distortion while recording, a very important advantage. The choice of a monaural recorder is easier. The Marantz 221 performs far better than the Sony 5000.

When evaluating cassette recorders, the first thing to make sure of is that it has a manual level control. The automatic record level control that is so handy for dictation is almost always ineffective for natural sounds.

A capability that some people need is loud playback in the field. If this is important for your use you should check the machine. In general, the stereo machines are judged to have marginal playback volume and the monaural are felt to be adequate.

For most types of bird recording we have found no noise reduction system that consistently works well. I mention this because sales people would have you believe that Dolby is essential on a cassette machine. While Dolby certainly reduces the noise, it can also add distortion to many bird sounds.

The decision between stereo and mono is governed by the uses you have for your recordings. For most bird recording, stereo is an unnecessary complication. However, if you are interested in recording ambient environmental sounds, then a stereo machine is preferred.

There are some recorders being offered on the market that have been modified to "improve" their performance. Tests at the lab indicate that there is no improvement, and some areas of performance are degraded. There is no reason that a stock recorder could not be improved with careful modifications. Claimed improvements should be documented along with confirmation that other specifications have not been degraded.
 

REEL-TO-REEL RECORDERS

The reel-to-reel recorder is the clear choice of professional recordists. With one exception all the recordings used on our field guide records are made with a reel-to-reel recorder.

The disadvantages of a reel-to-reel machine are weight and cost. The advantages are durability and fidelity of recording. Portable audio reel-to-reel recorders are available in 2 basic price ranges. The recorders made by Uher run around $1000 and the machines by Nagra cost from $4000 to $7000.

The Uher is a machine that is capable of very good performance but suffers from being somewhat susceptible to rough handling. We have found that Uhers do not survive well in the institutional environment. There are however, Uhers that have given years of good service to individuals who are willing to take the time to care for them.

The Nagra recorder is the recorder used by most professionals. There are 2 monaural machines that cost between $4000 and $7000 and a stereo machine that costs around $8000. The Nagra is the most durable tape recorder that can be bought. The Lab has 20-year old Nagras that are still in daily service. For our organization and many others it is actually the least expensive machine to own. While the initial cost is high, the cost per year over the life of the recorder is lower than other machines.
 

MICROPHONES

Along with a recorder you will need a microphone. There are 2 types that are directional enough for bird recording - the shotgun microphone and the parabolic reflector microphone. The 2 brands that seem to give the best service are Electro-Voice and Sennheiser.

A good shotgun mike for general use is the Sennheiser ME-88/K-3U combination. The cost of this system is about $500. The microphone is the combination of a preamp/power unit and a shotgun microphone capsule. The ME-88 is the shotgun tube and capsule, and the K-3U is the preamp. The K-3U can also be fitted with an ME-20 omnidirectional microphone capsule and used with a parabola.

The finest shotgun microphone I have found is the Sennheiser MKH-816, with a Rycote "zeppelin" style windscreen. The comparable omnidirectional microphone is the Sennheiser MKH-106.

A problem when hand-holding a microphone is that handling noise is picked up and recorded along with the bird. There are various shockmounts sold that are supposed to reduce this noise. Very few of those sold actually help. If you do not specifically know that a shock-mount works for hand-held use, try it before you buy it. A shockmount that had been designed to work with the Sennheiser ME-80 and -88 is available from me for $47.25.

A parabolic reflector is actually a combination of a reflector dish and a microphone. The microphone used in a small parabola should have an omnidirectional pickup pattern. A good microphone can be purchased for $125 and an adequate beginning reflector for $75. There are 4 basic types of parabolas in use at the lab:

1. The Dan Gibson, which is an 18-inch clear plastic dish with microphone (low quality) and amplifier. It is available from Geleco Electronics Ltd., 2 Thorncliffe Park Drive, Unit 28, Toronto, Ontario, Canada M4H 1H2, (416)421-5631.

2. The Roché parabolas, a 24- or 30-inch green fiberglass dish, no microphone included. It is available from Jean Roché, Haute Boire, 84640 St. Martin de Castillon, France.

3. The Sony PBR-330, a 13-inch clear plastic dish, too small for most high quality work. One potential supplier is Mineroff Electronics, 946 Downing Road, Valley Stream, NY 11580, (516)825-4702.

4. There are a variety of metal parabolas at the Lab with diameters of 18 to 40 inches. These are dishes that were manufactured by antenna companies and have had mike mounts added by the Lab. Some of these work extremely well but can be hard to find, heavy, and require the purchaser to construct their own mike mounts and handles.

It may be helpful in gaining a feel for the relative utility of different microphones and parabolas to compare their beam width to the field of view of lenses commonly used on 35 mm cameras. The comparison is approximate and assumes the frequency is 2500 Hz. If the frequency of the bird sound is lower, a larger parabola is required for equal performance.
 

Microphone
 Lens
36-in. parabola
200 mm
24-in. parabola
135 mm
18-in. parabola
l00 mm
12-in. parabola 
75 mm
Shotgun(best)
28 mm
Cardioid (unidirectional)
8-15 mm (fisheye)

FEEDBACK

The ability to evaluate the quality of your recordings in the field is absolutely essential. The loudspeaker that is built into the recorder is not adequate and can only by used in playback mode. Headphones allow you to hear the recording while the machine is in record and facilitate proper aiming of the microphone, as well as give a clear idea of the quality of the recording. If there is a problem with machine adjustment or should it malfunction, a pair of headphones will allow you to hear the problem long before it would be noticed on the machine's loudspeaker. By wearing headphones in the field you hear the problem while you are recording rather than hours or days later.

The choice of headphones is highly personal as to style and feel. They must however be an appropriate electrical match to the recorder. My favorite is the A.K.G. K-141, priced at about $70. A problem that has been found recently with the K-141's is that certain types of insect repellent will eat holes in the ear cushions. This could be a problem with other headphones, too.

An essential item for field recording is the pitch pipe. If a known pitch is recorded every so often along the tape, it is possible at a later time to adjust the playback speed to match the recording speed.
 

BACKGROUND

It is impossible in a short note to cover all the factors that should be considered when choosing a field recording system. Following is a list of some literature you might want to consult for more information:

Borwick, John, 1980, Sound Recording Practice, Oxford University Press.

Eargle, John, (1976)1980, Sound Recording, Van Nostrand Reinhold.

Gulledge, James L., 1976, Recording Bird Sounds, The Living Bird, Fifteenth Annual, Cornell Laboratory of Ornithology.

Wickstrom, David C., 1982, Factors to Consider in Recording Avian Sounds, Acoustic Communications in Birds, Kroodsma & Miller, Academic Press.

Woram, John M., 1982, The Recording Studio Handbook, ELAR Publishing.

Another way to learn more about recording birds is to take one of the courses that are offered, one at the Laboratory of Ornithology and one at the University of Maine at Machias. For more information, write to: Mr. Greg Budney, Library of Natural Sounds, Cornell Laboratory of Ornithology, 159 Sapsucker Woods Road, Ithaca, NY 14850

Dr. Charles Duncan, Institute for Field Ornithology, University of Maine at Machias, 9 O'Brien Avenue, Machias, ME 04654
 

NEW DIGITAL TECHNOLOGY

At the moment I think it is premature to consider 8 mm video recorders as a practicable alternative for amateur bird sound recordists. I do think that over time this format may well evolve to be something that is quite commonly used.

One of the major difficulties will be the fact that the microphone preamps do not have a very high gain. Another difficulty at the moment is that most 8 mm video cassette recorders have no means to set the record level. It is done automatically, the assumptions being made by the designers of these automatic level controls based on their use for human speech. In many cases this is totally inappropriate for recording birds.

Digital recording is being sold to the public as "perfection." This is not the case. It is a promising technology that is just starting to be developed. Digital tape recording does not remove tape hiss. To get the maximum signal to noise ratio in any medium one needs to record at as high a level as possible without distortion. Some commercial versions of digital recordings have a signal to noise ratios poorer than what is capable of being produced by any cassette tape recorder currently manufactured.

Some less expensive digital recorders use noise reduction systems of their own and they are generally inappropriate for bird sound recording. The place to address the noise problem is at the time of recording. This would best be done by getting very close to the bird, using a large parabola. As that is impossible in many situations, one uses an intervening amplifier between the microphone and the recorder to bring the signal up to the proper level.

I believe that currently the longest cassette available for 8 mm video systems is 2 hours. I have seen "pulse code modulation" processors used in conjunction with a standard VHS or Beta VCRs and in that case one can get as much as 6 hours of recording per tape.

A factor that is often overlooked with the video and digital machines is that they are relatively power hungry. They use rechargeable batteries with a charge giving about 2 hours of use. This can be a problem for recordists working in areas without handy outlets in which to plug the chargers.

I have tried some of this technology. There are people using it, with varying results. I would say that we are about a year ahead of when a reasonable assessment can be made as to which and what digital recording apparatus is appropriate for bird recording.

Manufacturers are due to introduce digital audio cassette machines, if they have not already, and portable models are projected. Audio and Digital Audio magazines have had a few preliminary articles on what this format may be like.

* Reference to trade names does not imply an endorsement.
 


All contents, text and images are copyright 1987, 1999 by David Wickstrom
and 1988 by Oregon Birds
No unauthorized use is permitted.
Email - d ave @ dwickstro m . com

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