Nature recording with the Sony PCM-D100

The Sony PCM-D100 is a medium-sized portable recorder that was released in late 2013.  It has become very popular among field recordists, and is often carried as a backup for professional gear.  I purchased one in March 2016 to record ambient nature sounds, and I’ve used it extensively.  Paul Virostek, of Creative Field Recording, has a detailed review here.  Below I summarize the recorder and add my impressions.

The Build

The D100 is a sturdy, well-built recorder.  It is slightly larger than the Zoom H4n and Zoom H5/H6, so it is a bit too large for most pockets, but does fit nicely in your hand.  It is rather sensitive to handling noise, so it’s best on a tripod or handheld shock mount.  A pair of 15 mm electret condenser microphones mounted on top can be rotated to 90 (X-Y) or 120 degrees (wide).  A 3.5 mm input jack supplies plug-in-power (2.5 mV), but lacks XLR jacks and the ability to provide phantom power.  This makes the recorder a rather odd duck, as there are other recorders, including the Zooms mentioned above, the Olympus LS-100, the Marantz PMD-661mkII, and Tascam DR-100 mkII, that are similar in size, quite a bit cheaper, and do provide phantom power for professional microphones.  It is more akin to the Nagra SD, a well-built small recorder with attachable modular mics and a 3.5 mm input jack.  Where both of these recorders shine compared to the others is very quiet pre-amps.  Unfortunately, I’m not aware of any direct comparisons between the D100 and Nagra SD.

The Sony PCM-D100

The Sony PCM-D100

Left side controls of the Sony PCM-D100, showing location of the volume knob for the speaker and headphones, and the mic/line and attenuation switches.

Left side controls of the Sony PCM-D100, showing location of the volume knob for the speaker and headphones, and the mic/line and attenuation switches.

The right side of the Sony PCM-D100, showing the gain knob, power, hold and light switches, and the external mic and line ports.

The right side of the Sony PCM-D100, showing the gain knob, power, hold and light switches, and the external mic and line ports.

The recorder has a nice LED screen that’s easy to see in sunlight, and can be illuminated for use in the dark.  Start up is very quick (< 2 seconds), and menus are easy to navigate.  Gain for both onboard and external microphones is controlled by a large knob on the side, which has a guard to keep it from rotating accidently.  Left and right gain is ganged by default, but pressing the center of the gain knob releases the gang, allowing right and left mics to be adjusted separately.  Volume for the built-in speaker and headphone jack is via a knob on the left side of the recorder.  It is somewhat protected by plastic guards, but in my opinion, still rotates too easily.

The D100 comes with 32 gb of built-in memory plus an SD card slot that also takes Sony Memory Pro sticks, and automatically switches from onboard to memory card (and vice versa) if needed during a recording.  It has a micro-b USB interface and easily connects with your computer for file transfer.  It is powered by 8 AA batteries, kept secure in a sled accessed from the bottom of the recorder.  It cannot be recharged or powered by USB.  It can get 12 hours or more from the AA batteries, so it can handle some overnight recording.  It will automatically power down when not in use.  It has a small speaker near the base; useful for reviewing recordings, but not good for high fidelity playback.


The D100 can record in WAV or mp3 formats (including both at once), as well as DSD.  It can also play FLAC, WMA and AAC files.  It can record up to from 44.1 kHz/16 bit, to 192 kHz/24 bit resolution, so it is capable of high-frequency recording of bats, rodents, and insects, although little testing has been done on the very high frequency fidelity, so it may not be as good as a dedicated bat recorder.  It includes a 5-second pre-record buffer.  Sound quality of both the onboard mics and external pre-amps is excellent.  I compared it with both my Zoom H4n and Sony PCM-M10, and the difference was very noticeable.  I also had the chance to compare it with a Zoom H5.  What was most noticeable in comparing the M10 and H5 with the D100 wasn’t so much audible noise floor, but that sounds were cleaner and crisper with the D100.  In my case, I was recording birds in my front yard, and even with simultaneous recordings, it sounded like you could hear more birds with the D100.  The following recording was made in my front yard in Arizona, with both recorders running simultaneously.  You can hear some distant traffic and a breeze through the trees, plus some distant birds.  The Zoom h5 is first, followed by the D100.


I’m not sure, however, the difference in sound quality is worth the the difference in price.

Using in the field

The D100 has a couple of what I consider design flaws, from a nature recording standpoint.  Before I explain them, I will describe how I typically record.  I use the D100 in one of three ways: A) from in the car (overnight), where I keep the recorder close by, and connected via long cable to external mics; B) in the field attached to external mics; or C) in the field by itself using the onboard mics.  In the first scenario, I keep the recorder in a small cloth pocket attached to the rear seatbelt attachment point (you can read about how I converted my CR-V to a camper here).  If a sound wakes me up, I can reach up and grab the recorder and ear buds, and hit the record button.  Moving the recorder in and out of it’s pocket is enough to shift the volume knob for the headphones, and after having my ears blasted too many times, I’ve finally learned to turn it all the way down before I hit the record button, then slowly turn it up.  It would be nice if the knob didn’t turn so easily.

In the last scenario, wind protection is necessary for the onboard mics.  The D100 comes with a furry wind cover, which is both very difficult to get all the way on, and only does a modest job of protecting from the wind.  I also discovered you had to be very careful to check the switches on the upper left side of the recorder, as they were easily moved when applying the wind cover (see photo above).  This could result in a switch being moved from mic to line, and/or no attenuation to 20 dB attenuation.  If you weren’t aware the switches had been moved, you have to spend some time trying to figure out what is wrong with the recorder and why the mics don’t seem to be working.  I purchased several other wind covers to try to find something that would allow me to use the onboard mics.  The first was the Guttman Microphone Windshield for Sony PCM-D100.  It was nearly impossible to get on and provided very little wind protection.  The second was the Movo WS-R30.  This is a furry cover with a large rubber gasket on the bottom (see top photo).  It went on pretty easy without flipping the switches, and provided slightly better wind protection than the Sony.  Lastly, I tried the Rycote windshield for the D100.  It went on as easily as the Movo, but surprisingly, didn’t provide any more wind protection.  In addition, it attenuated more mid-frequency sounds.  That might be a good thing if you are trying to record dialogue or close sound effects, but if you are trying to record wind as part of a soundscape, it is less than desirable.  So I am still searching for a good wind cover that will allow me to use the D100 in the field with onboard mics.  Some other recordists have described DIY wind covers using plastic or foam balls, covered with a Rycote Baby Ball gag.  X-Y mic arrays are difficult to protect from the wind, so I don’t fault Sony for that, but having the mic/line and attenuation switches so close to the mics where they can be flipped when putting on wind covers is not the best design.  Here’s a sample of the wind with the Sony, Movo, and Rycote covers (in that order; I didn’t test the Guttman because after struggling for several minutes to put it on, I gave up).  It was recorded next to a stream, on a day with 5-10 mph gusts, and as you can hear, the wind broke through with all 3 covers.  The recorder was set with a 150 Hz low-cut filter.   I didn’t amplify the recordings, so you might have to turn up the volume on your speakers or headphones.


S/N 100

The D100 is advertised as being able to achieve a remarkable signal-to-noise (S/N) ratio of 100 dB.  It does this via software, although Sony is sketchy about providing details.  Paul Virostek does a nice job of explaining how the standard limiter works, and his theory about how the S/N 100 setting works:

I’ll explain: the D100 is always recording two levels at the same time. One of them is the level you set with the gain dial. The software records the second at precisely 12 dB lower than the levels you set. When the original level peaks, the software simply grabs and uses the healthy, lower level instead.

This is how the D100’s standard limiter operates. So, if you are recording a conversation at, say, -6 dBFS, then a someone yells to bring the signal above 0 dBFS, the D100 will smoothly swap out the distorted yell for the second, lower-level signal it is also recording at the same time, saving the recording. It will then switch it back when the louder levels diminish.

The S/N 100 dB’s setting is similar, but since it is intended for quiet sounds, it works the opposite of the limiter. It will always record with the lowest of the two levels it is capturing, but then switch to the louder version of the two when it detects prominent audio.

So, let’s say you are recording a quiet clothing rustle. The S/N 100 dB’s setting will standardly use the quiet level, keeping the “noise floor” low. When it detects audio from a fabric scratch, it will switch to the louder (+12 dB) gain dial level to capture it, then diminish to lower level when the cloth shuffle ends. The result? The recording will appear to have a lower noise floor when no significant audio is present.

If this is correct, then the S/N 100 setting works similar to a noise gate on a cell phone – dimming the background sounds to make the foreground sounds clearer.  In many cases, this is desirable.  But if you are making ambient recordings, you often want those subtle whispers in the background to add depth and flavor to your recordings.  Until I read Paul’s description, I had kept my D100 with the S/N 100 setting on (because who doesn’t want an S/N of 100 dB?), and in some of my recordings I could detect a dull thumping sound, as it switched from very quiet sounds to more prominent sounds.  I have since left the S/N setting off (an easy menu setting), and I like the more natural feel to the recordings.


The D100 is a nice, mid-sized recorder.  It has a nice build quality, it is easy to use, has quiet preamps, and nice onboard microphones.  From a nature recording perspective, it does add a lot of low end (this seems to be a Sony thing, and easily modified with low-cut filters), and it is very difficult to wind-protect the onboard mics.  I’m happy with my purchase (especially since I found an open-box special at B & H Photo and saved $150 USD), but I’m not sure I would recommend it to a beginning recordist.  The small Zooms and Tascams have a lot more features, including the ability to power professional microphones for several hundred dollars less.  So if you need to flexibility to use multiple microphones, they are a better deal for the money.  On the other hand, if you need really quiet preamps, the D100 is worth a look.