Recording ambience is an awesome experience. Travelling to the location, setting up, and actually using the recordings in film, television, and other media is a fulfilling job in the audio engineering world.
When it comes time recording ambiences, which microphones work the best? In this article, I’ll share with you my top 3 microphone recommendations for recording ambience, whether that be in mono, stereo, surround sound or ambisonic.
Here are my top 3 recommended microphones for recording ambience:
- Rode NT55: A pair of Rode NT55s (link to check the price on Amazon) work fantastically as a stereo pair for ambient recordings. These mics have low self-noise and switchable cardioid/omnidirectional polar patterns, making them a versatile and accurate pair for recording any kind of ambience.
- Zoom H4n Pro: The Zoom H4n Pro (link to check the price on Amazon) is a favourite of many professional and amateur recordists. Because ambient recording will often take you far from the studio (or other indoor environment), it’s nice to have a durable, compact stereo microphone/recorder. The Zoom H4n Pro kills two birds with one stone (as you capture the sound of the ambient bird chirps) by combining an XY stereo pair and a recording device.
- Core Sound OctoMic: The Core Sound OctoMic (link to check price on Core Sound website) is an 8-diaphragm ambisonic transducer. This “microphone” is a serious feat of engineering. The OctoMic is an ideal choice for recording ambience, VR360, video games, and has numerous other applications. Though perhaps a little “out there” in its design, this unique microphone has the potential to capture the most detailed ambience recordings you’ll ever hear!
We’ll get into the details of each of these mics shortly, but first let’s look at the factors that make a great ambience microphone.
What Makes A Great Ambient Microphone?
- High sensitivity: Choosing a microphone with a sensitive diaphragm and strong output will effectively reproduce the nuances of sound in an ambient environment.
- Mixing format variety: Ambient recordings are often reproduced in stereo, surround, or ambisonic formats. Choosing a mic with stereo, surround, or ambisonic outputs can cut costs (over duplicate “mono” mics) and simplify the ambient recording set up.
- Low self-noise: Select a mic with low self-noise value to output a pristine representation of the true ambience around the mic.
- Durability: Choose a microphone that will function properly in a variety of ambient conditions (indoors and outdoors). Use windscreens, shock mounts, and other protective devices when needed.
- Flat/extended frequency response: Pick a mic with a flat frequency response to more accurately reproduce the ambient sound.
- Omnidirectional polar pattern: Omnidirectional microphones sound the most natural since they capture sound from every direction in practically the same way without off-axis colouration.
Now let’s dive into the Rode NT55, Zoom H4n Pro, and Core Sound OctoMic, focusing on the above criteria.
The Rode NT55
The Rode NT55 is a small diaphragm “true” condenser microphone. This pencil mic has two interchangeable capsules that provide either omnidirectional or cardioid polar patterns.
Although this microphone is intended for recording acoustic instruments, it works very effectively as an ambience microphone (both as a single mic, matched pair, or in other microphone arrays/formats). Its high reactivity, low self-noise, and consistent pick up pattern make it a top choice for recording ambience.
A main benefit the Rode NT55 has over the other two microphone recommendations is that its positioning in an array is flexible. When recording with multiple NT55s, we have the freedom to set up any type of microphone array, whether that be a spaced pair or a more involved surround sound or ambisonic miking technique.
Sensitivity Of The Rode NT55
The sensitivity rating of the Rode NT55 is given as -38 dB re 1 Volt/Pascal (12 mV @ 94 dB SPL) +/- 2 dB @ 1kHz. This is a fairly standard rating for a true condenser microphone. This microphone will output a usable signal even in quieter ambient settings.
For more information on microphone sensitivity, check out my article What Is Microphone Sensitivity? An In-Depth Description.
The small diaphragm of the NT55 is very accurate and will reproduce the nuances in an ambient environment.
Formats Of The Rode NT55
The Rode NT55 is a regular mic with one balanced XLR output. I would suggest using at least a pair of NT55s in a stereo spaced pair arrangement.
For more information on microphone output signals, check out my article Do Microphones Output Mono Or Stereo Signals?
If the project calls for it (and has the budget), or if you just want to get more creative, a surround sound or ambisonic miking technique would yield excellent results as well. These technique require much more than two microphones.
For more information on stereo miking techniques, check out my article Top 8 Best Stereo Miking Techniques (With Recommended Mics).
Self-Noise Of The Rode NT55
The Rode NT55 has a rated self-noise of 15dBA. This is an excellent rating which will not introduce unnecessary hiss to the ambient mic signal. It’s also very unlikely that the microphone will mask the nuances of the ambient noise (very rarely is there ever an ambient setting that has noise floor below 15 dBA).
For more information on microphone self-noise, check out my article What Is Microphone Self-Noise? (Equivalent Noise Level).
Durability Of The Rode NT55
The Rode NT55 is built with a heavy-duty satin-nickel plated body. It can withstand some physical abuse, though I never recommend abusing high-quality microphones (or any microphones, really).
The main issue with the Rode NT55 is that because it is a true condenser microphone with active electronic circuitry and the need for electrical polarization in its diaphragm, it doesn’t fair so well in high humidity and moisture. Therefore, special care must be taken if the Rode NT55 is tasked with capturing the ambient sounds of rainfall and other wet environments.
Frequency Response Of The Rode NT55
The Rode NT55 has a frequency response that ranges across the human range of hearing (20 Hz – 20,000 Hz). Here is its frequency response graph, which shows both of its selectable high-pass filters.
We see in the above graph that the NT55 has a very flat frequency response except for its large boost in sensitivity in the high-end frequencies.
Though the high-end boost seems quite excessive, the NT55 still sounds very natural in ambient settings. Add the fact that a windscreen and other protective material will likely be surrounding the mic capsule, and the boost actually helps to maintain a flatter response in the upper-frequencies.
As for the high-pass filters, engage them as you see (hear) fit. The 75 Hz HPF will likely eliminate any unwanted low-end rumble in a mic signal while the 150 HPF may eliminate too much low end. When recording ambience, it’s often best to capture the entire frequency spectrum for the most realistic capture of the environment.
For more information on microphone high-pass filters, check out my article What Is A Microphone High-Pass Filter And Why Use One?
All in all, the NT55s frequency response is suited very well for ambient recordings.
For more information on microphone frequency response, check out my article Complete Guide To Microphone Frequency Response (With Mic Examples).
Polar Pattern Of The Rode NT55
The Rode NT55 has two interchangeable capsules that yield a cardioid or an omnidirectional polar pattern. When recording ambience, I would always suggest using the omnidirectional capsule for the most natural results.
Here is the official polar pattern diagram for the Rode NT55’s omnidirectional polar pattern:
As we see, the NT55 becomes slightly more directional at higher frequencies. However, this difference is minuscule and negligible. The polar pattern of the NT55 is considered very consistent and works amazingly well at capturing the ambient sounds from all directions.
For more information on the omnidirectional microphone polar pattern, check out my article What Is An Omnidirectional Microphone? (Polar Pattern + Mic Examples).
The Zoom H4n Pro
The Zoom H4n Pro is an exceptional microphone/digital audio recording device. It is an upgraded and updated version of the discontinued original Zoom H4n.
The H4n Pro is a digital field recorder with a built-in XY stereo pair of microphone capsules. It is a compact, easy-to-use recording device that is an amazing choice for recording ambience.
As a stereo microphone pair, the H4n Pro works efficiently to record binaural digital audio in .wav and .mp3 formats with the following bit depths and sample rates:
|Sample rates: 44.1 / 48 / 96 kHz|
Bit depths: 16 / 24-bit
|Sample rates: 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256,|
320 kbps, VBR
Bit depths: 44.1 kHz
This little handy recorder proves to be an excellent choice for recording ambience. Let’s talk about the H4n here in a bit more detail:
Sensitivity Of The Zoom H4n Pro
The sensitivity rating of the Zoom H4n Pro’ built-in mics is -45 dB/1 Pa at 1 kHz. This is a reasonable sensitivity rating and the H4n Pro will capture strong mic signals that recreate the ambience around them.
The capsules themselves are small and reactive, allowing the H4n Pro to capture an accurate sonic picture of the ambient sounds around it.
Formats Of The Zoom H4n Pro
The built-in microphones of the Zoom H4n Pro offer a stereo XY pair at 90° or 120°. This allows the recorder to remain compact while allowing for a wide stereo image.
A really cool part of the digital software of the H4n Pro is its mid/side encoding. A mid/side recording is made possible through this encoding with the XY pair at the front of the mic/recorder.
The Zoom H4n Pro offers 4 channel recording (2 internal mics + 2 external mics). This makes it entirely possible to utilize the H4n Pro as a digital recording device only and have an external stereo pair (like the Rode NT55s) act as the microphones. Alternatively, we are able to record 4 channels for use in surround sound.
So the Zoom H4n has plenty of format options to choose from. I would recommend experimenting with various arrays and listening critically to what sounds the best to you.
For more information on analog and digital microphones, check out my article Are Microphones Analog Or Digital Devices? (Mic Output Designs)
Self-Noise Of The Zoom H4n Pro
The H4n Pro does not have a specified self-noise rating. This is likely due to the mics immediate amplification and conversion to digital information. However, when listening back to my H4n and H4n Pro recordings, the background ambient noise is always clear (though annoying). The self-noise is low enough to not bury the ambient sounds of any practical ambient environment (nobody records ambient sounds in an anechoic chamber).
Durability Of The Zoom H4n Pro
The Zoom H4n Pro is a compact digital recording device. There’s a lot of intricate circuitry and digital components. For that reason, care should be taken not to abuse the H4n Pro.
Caution should be exercised when recording with the H4n Pro is strong weather conditions. The H4n is not waterproof or sandproof and so the necessary protective step must be taken when recording in difficult ambient environments. Try tougher exterior microphones instead of the built-in mics and have the H4n Pro positioned in a safe space.
Frequency Response Of The Zoom H4n Pro
Like the polar response, Zoom does not explicitly state the H4n Pro’s frequency response. However, it is seemingly 20 Hz – 20,000 Hz with perhaps a bit of extra sensitivity in the upper frequencies.
Again, if you’re unhappy with the internal microphones of the Zoom H4n, you can always utilize other mics, using the H4n simply as a field recorder device.
Polar Pattern Of The Zoom H4n Pro
As mentioned, the Zoom H4n Pro has a built-in XY pair. Each of these microphones is a unidirectional condenser and the XY angle has an option between of either 90° or 120°. This is perfectly fine way of recording stereo ambience.
Again, the H4n Pro as a field recorder will accept two other mic inputs, allowing for greater flexibility in mic polar pattern and array.
The Core Sound OctoMic
The Core Sound OctoMic is the world’s first second-order ambisonic microphone.
What is an ambisonic microphone? An ambisonic microphone is a single mic designed to capture sound in a full-sphere surround sound format. Ambisonic mics often include 4-8 capsules (or more) in order to output sound for 3D ambisonic mixing. Ambisonic mics are well suited for virtual reality and ambience recording.
OctoMic is the described as the ideal microphone for recording Virtual Reality projects like cinema, video games, music and ambience. With proper mixing in post-production, the OctoMic is capable of capturing ambisonic (spherical surround), surround sound, and even stereo and mono ambient recordings.
The OctoMic is designed with 8 identical electret condenser cardioid capsules measuring 12 mm in diameter. These 8 capsules are arranged in a second-order ambisonic array on a precision machined mount.
Sensitivity Of The Core Sound OctoMic
The sensitivity per capsule of the Core Sound OctoMic is given as 7.0 mV/Pa nominal (-43 dB ref: 1V/Pa). So each mic capsule outputs a fairly low level mic signal when subjected to varying sound pressure.
For this reason, a high-quality preamp is highly suggested to amplify each of the OctoMic’s 8 capsules. Core Sound suggests pairing their OctoMic with the Sound Devices MixPre-10T or the Zoom F8.
As for the reactivity of the OctoMic’s capsules, they do an amazing job at capturing the details of the ambient noises in the environment, recreating a stunningly accurate sonic picture of what’s going on around them.
Formats Of The Core Sound OctoMic
The formats are plentiful with this second-order ambisonic microphone. Depending on the mixing format you decide on, the OctoMic is capable of providing the following formats for your ambient recordings:
- mono (without “sum to mono” phase cancellation issues)
- binaural, using individualized or generic HRTF information
- four speakers arranged as a square or rectangle
- six speakers arranged as a regular or irregular hexagon
- 5.1 (ITU)
- any of the above plus height information (e.g., two hexagonal arrays of speakers, one above the listener and one below)
- and many, many more.
Self-Noise Of The Core Sound OctoMic
The self-noise rating of the OctoMic’s complete array is only 15 dBA. That is astonishingly low for 8 microphone capsules combined. It’s safe to say that the self-noise of the OctoMic will not bury even the quietest ambient sounds.
Durability Of The Core Sound OctoMic
The Core Sound OctoMic is not over durable. It is a fairly sensitive microphone with precisely positioned capsules.
I would never suggest using the OctoMic in harsh weather conditions and would always suggest securing it properly and safely when recording outdoor and indoor ambiences. The last thing you’d want is to drop this precision recording instrument.
The OctoMic also comes with its compact PPAc8 transmitter box. This converts the 8 capsule unbalanced outputs to 8 individual balanced mic outputs and also allows for the powering of the OctoMic itself (whether that’s per channel from the connected mic preamplifier’s Phantom Power or from an external battery pack). This is all to say that the PPAc8 must also be well taken care of when recording with the OctoMic in ambient environments.
Frequency Response Of The Core Sound OctoMic
The frequency responses stated on the Core Sound OctoMic specifications sheet are as follows:
- Raw: 40 Hz – 18.5 KHz +/- 4 dB
- Calibrated: 30 Hz – 18.5 KHz +/- 2 dB
Core Sound also states that they could calibrate the response down to 20 Hz (the lowest limit of human hearing) while jokingly saying that a calibration this low would be best used for detecting earthquakes.
So the range of the capsules in the OctoMic does not encompass the entire range of human hearing (20 Hz – 20,000 Hz). However, the frequency response of each capsule is flat and sounds very natural when capturing the sound of ambience in any application.
Polar Pattern Of The Core Sound OctoMic
Each of the 8 capsule of the Core Sound OctoMic has a cardioid polar pattern.
When recording with an ambisonic microphone, it’s often necessary for additional software to effectively decode/encode the microphones for proper formatting in the chosen mixing format.
In ambisonics, A-Format is the raw recording where each individual mic capsule has its own output and recording channel. B-Format is the proper format for positioning the ambisonic mic capture in a 3-D space (or other mixing arrangement).
VVOctoEncode is the A-to-B-Format encoder VST plugin supplied with OctoMic. It was developed and is supported by David McGriffy (VVAudio.com).
With that being said, the cardioid pattern of each OctoMic capsule will widen in a first-order OctoMic setup (using a tetrahedral array with only 4 mic capsules). Conversely, the capsule polar patterns will become narrower in a second-order OctoMic setup (using all 8 mic capsules).
Here are the first-order and second-order polar patterns of the OctoMic capsules:
In either order, the OctoMic effectively capture all sounds around it with negligible colouration.
So those are my top 3 microphone recommendations for ambient recordings along with my explanation for each. To recap, they are:
- Rode NT55: Best single microphone for recording ambience. Use more than one NT55 for flexible stereo imaging and for other mixing formats
- Zoom H4n Pro: The top microphone/digital audio recorder combo for recording ambience. The H4n Pro is great on its own and for use with other professional microphone pairs.
- Core Sound OctoMic: The top ambisonic microphone for recording ambience.
For all the My New Microphone mic/gear recommendations, please check out my page Recommended Microphones And Accessories.