Sampling: Optimal Sound Recorder Settings

dr-08_mic_2I like recording the sounds of nature, and when I play my recordings back, I want them to sound exactly like when I was there. Here is my technique, equipment, and settings I use.

The Technique, Equipment, and Settings

ISI-HMAB-1

This effect of “being there” is achieved through binaural recording. Binaural recording, simply and for my purposes, is recording sound with two microphones separated by a human head. By doing this, you get an authentic reproduction of the sound as if your ears were hearing it. I have a set of headphones that, instead of playing the sound back to my ears, record sounds through tiny microphones located where the headphone speakers would normally be. The microphones are pointed outward and away from my ears. They are model/part #ISI-HMA-1 available from SoundProfessionals. An amplifier is needed for most inputs to recorders, so the purchase of that is required as well. It is a battery operated device that amplifies the signal from the tiny microphones so that your recording device can have a signal to work with. For the DR-05 and DR-08 that I will describe next, I have used this binaural headset without the amplifier, and it seems to work o.k.

I have also just used my recorder to achieve the same or similar thing. This way I don’t need to have the amplifier and headphone microphone set-up.

I can get a great binaural effect right in the recorder itself!

DR-08_mic_2

DR-08

The recorders that I use are a Tascam DR-08 and a Tascam DR-05. They are both compacts with built-in binaural recording capabilities. The microphones are separated to achieve that binaural sound effect of “being there” and the recorders can be taken almost anywhere in my shirt or coat pocket.

They record onto micro-SD cards and have inputs for USB transfer of files. They can record files in the WAV or MP3 format. I usually record in MP3 format. This is the simplest and fastest way, and also produces the most compact file size. I record without equalization and with the sensitivity set to high. For loud sounds, I would adjust the sensitivity to low, but I haven’t encountered that yet in my recording of nature sounds (almost though with loud thunder).

The DR-05 allows automatic level setting, and I use that whenever I can. This is accessed when the recorder is on standby. I adjust the recording level input to 90 (max) then use the Peak Reduction function during the recording. By doing this, the level is automatically set to the highest that does not distort. This setting is retained after recording. If I record a thunderstorm, for example, the peak level from the first thunder will set the max level to the point it will not distort and maintain that level throughout the recording. If a louder noise occurs later, the level will again be set lower to accommodate that peak level.

The DR-05 also allows for peak limiting with the Limiter setting instead of the Peak Reduction. I use the Limiter if I plan to manually set the recording level. I adjust the recording level to where the average sounds hover around the -12dB mark on the display, then if an excessive level comes in, it will be limited by the Limiter. This can be useful if I want to capture the low-level sounds of falling rain at a listenable level, while not distorting the high peaks of a thunder clap.

The third automatic level setting on the DR-05 is the Auto Level setting. Using this instead of Limiter or Peak Reduction moves the recording levels up and down based on the incoming sounds. This can be good for recording nature but will produce abnormally high lows and unusually low highs, so this can ruin the realism. When I am recording industrial sounds of varying amplitude where realism is not expected, I use this setting, It is best suited for recording conversations and meetings.

As for the sampling rate ( the speed at which data is recorded during an audio recording), I use 320 kb/s (or kbps) for most recordings. That is 320,000 bits of digital data recorded every second. The maximum for an MP3 file is 320 kbps. I’ve had good luck at 192 kbps also, but 320 kbps is better. (If you’re curious, a CD is 1411 kbps.)

To take recordings, I put my recorder on a window sill or in a sheltered area outdoors, push the record button and step away. I get about 20 minutes worth of recording for any particular sound. Invariably there are unwanted noises on the resulting file that have to be removed.

Capturing sounds with my Tascam DR-05. 🎤 #tascam #sounds #recording

A post shared by Lars Lentz (@larslentzphotography) on

For editing, I use the free Audacity software. It takes some getting used to, but this software really works well for editing audio files. Clipping out offending noises is easy, and fade-in and fade-out functions work well. You have to download the free LAME encoder to be able to write MP3 files once edited, but the LAME encoder is far from lame and produces excellent-quality MP3 files. The instructions for installing LAME are embedded right in the Audacity software, so there is nothing to download additional ahead of time.

Adding music and loops is possible by using a DAW (digital audio workstation). MP3 files recorded and edited in Audacity are easily imported into DAW software where music loops and effects can be added.

Additional resources are available at these helpful links:
FACT Magazine’s “A Beginner’s Guide To… Field Recording” by Lawrence English

Conclusion

That is how it is done using my set-up. There are many other choices available out there, but I chose this one as a low-cost alternative to other more expensive set-ups. You can do the same and achieve similar quality files by following these guidelines.

“Why do I record these sound files? I think people may want to hear the sounds of nature, and I believe it can promote relaxation by listening. Besides, it’s kind of fun”.

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