Digital audio recorders
A digital audio recorder is a key component of a system used to capture vocalizations, but selecting one can be challenging. Most of the commercially available equipment is designed for recording music and the human voice with close and cooperative subjects. Few audio recorders are specifically designed for the quick onset and rapid frequency changes characteristic of wildlife sounds or the rigorous field conditions faced by biologists and birders.
Many recorders offer the same capabilities with varying degrees of special features, both essential and nonessential. A “good” recorder for the biologist or citizen scientist is one that balances your personal needs and desires. Check out our 2019 Gear Review for a comparison of some popular recorders.
A digital sound recorder is an investment, and the more you invest the better quality recordings you will be able to make. Still, some recorders are a better value for your money. Check out our Gear Review page for some options.
Recorder’s microphone preamplifier performance
Cleaner pre-amps result in better recordings
Layout of controls
Being able to quickly press Record or adjust record level is key in field settings, so be sure to consider this when choosing a recorder. Consider the layout of the recorder in its field case as well.
The quality of materials and construction can be very important on a machine you plan to use extensively in the field.
Balanced (XLR) input
Three-pin XLR connections are less prone to outside interference from cell phones or radio towers, as well as being more robust, than unbalanced connections through 3.5mm mini plugs. They are also required to power many microphones (see next paragraph).
Phantom microphone power
Phantom power, the ability to power a microphone through the cable, can be helpful and is required for some microphones that do not have their own power source. Only recorders with XLR inputs can provide this type of power.
File type, bit-depth, and sample rate
The ability to record uncompressed (.WAV) files is very important in capturing high-quality natural sounds; see our Why WAV page for more information. Similarly, bit depth determines the range of amplitude you can record and sample rate determines the range of frequency. At least 24-bit and 48 kHz are preferred, and 96kHz sample rate or higher may be required depending on what you are trying to record. Some newer recorders offer 32-bit recording that gives you an even greater range of amplitude and simplifies the level-setting process.
If engaged, a pre-record buffer allows a few seconds of audio to be recorded before pressing the record button. Often this is limited to 2 seconds, though some recorders allow for higher values. In some situations, this can mean saving the beginning of an important recording that might otherwise have started too late.
Being able to see the screen in the field is important. The size of brightness of the screen as well as the prominence of the level meter can affect how well you can operate the machine.
Recorder power options
The ability to take AA batteries adds flexibility to power options. Internal rechargeable batteries save money but are harder to replace. External lithium rechargeable batteries can dramatically increase record time but add weight to the recording set-up.
Some recorders use more power than others, so battery life in the field can be a major factor. Consider using an external lithium rechargeable batteries for recorders that are less efficient.
A properly fitting case can protect the recorder as well as make it easier to use in the field. Most larger recorders have custom-fitted field cases available from a variety of manufacturers. Some small recorders don’t work well in a field case and must be hand-held or mounted directly on a strap or lanyard.
Size and weight
Portability versus function and quality are important factors to consider when choosing a recorder.
Sound Devices MixPre-3
The MixPre-3 is proving to be an excellent unit for recording birds and other natural sounds. Its compact size and simplified menus, as well as more reasonable price tag, gives it an advantage over Sound Device’s other popular recorders. The large, colorful LCD touch-screen is pretty and easy to see in the field, and the vertical alignment when in a field case is a big plus. Once the menus settings are configured, operation is smooth and simple, with record and stop buttons and gain controls all positioned conveniently on the top of the unit. The sound quality is excellent, and the XLR inputs and phantom power allow use of a wide variety of external microphones. As with many recorders, the MixPre-3 is geared towards journalists and sound producers, so many of the options for mixing and USB audio are not applicable to typical field recording, but neither do they get in the way of the key functionality. Like other models from this company, the MixPre-3 seems to be robust and durable, especially when used in an appropriate field case. As of December 2018, a firmware update has added the option for up to a 5-second pre-record buffer, something that had been lacking in the initial release.
Cons: Battery life seems to be the single biggest concern for this model, with a set of four AAs not lasting even a single morning of recording. The optional 8-battery sled is a possible solution, but an external lithium battery to power the unit via the USB-C port on the side is probably the best way around this shortcoming. This works well where electricity is easily accessible, but those in search of a recorder for remote field sites should take this into account when considering this unit. Turning down the brightness of the screen and LED monitors can also help with battery life and is recommended. Also, the position of the SD card slot (behind the battery sled on the underside of the unit) is rather inconvenient but not a deal-breaker. Finally, the power switch is quite small and with an external battery plugged into the USB port, can be rather tricky to switch on.
- 3 separate XLR balanced inputs
- High-end, low noise microphone preamplifiers
- Manual record level control
- 48V phantom microphone power
- 1/8-inch headphone jack
- Maximum bit-depth: 24 bit
- Maximum sample rate: 96 kHz
- Records to SD card
- Up to 5-second pre-recording buffer
- Large bar-graph meter/display on bright LCD screen
- Powered by 4 AA batteries; 8 battery sled available; can also be powered through USB-C port by external battery or by Sony L-type batteries with another sled option
- Field case available (Strut STR-MP3, Portabrace AR-MIXPRE3)
- Vertical orientation in field case helpful for use in the field
- Weight: 480g (16.8 oz) excluding batteries
- Dimensions: 144 x 110 x 36 mm (5.7 x 4.4 x 1.4 inches)
While more expensive than some of the other mid-range recorders, between its sound quality, portability, and ease of use, the MixPre-3 is definitely worth it. A larger, more expensive version with six channels, the MixPre-6, is also available, but is unlikely to appeal to most nature recordists for whom its additional channels and functionality are largely overkill.