Surround sound, when done correctly, offers a much more immersive than typical mono and stereo audio. Like mono or true stereo, there are true surround sound miking techniques that allow us to capture true surround sound audio in real-time with microphones.
The top 4 best surround sound miking techniques are:
- OCT Surround
- Corey/Martin Tree
- Fukada Tree
In this article, we’ll get to better understand surround sound and take a look at miking techniques that will yield the best surround sound recordings.
What Is Surround Sound?
Surround sound refers to a multitude of techniques that augment the spatial realism of sound reproduction with the use of multiple audio channels played through loudspeakers that surround the listener.
With proper surround sound listening environments, audio can be mixed and panned in ways that place the sound in specific directions around the listener.
As mentioned, this is done with loudspeaker placement around the listener. The listener’s ears, then, will naturally perceive sound emanating from individual speakers as having a directional property.
This yields much more directional and spatial flexibility than standard stereo audio which only has left and right audio channels.
Surround sound formats vary widely from one another but all share one thing in common: they are all designed to improve the spatial sound experience of the listener by adding additional audio channels and loudspeakers to playback systems.
What Is Surround Sound Miking?
Surround sound miking is typically “true-surround,” where each surround sound channel (left, right, centre, surround left, and surround right) has at least one microphone assigned to it for surround sound mixing. Some techniques (especially when recording ambience), however, drop the centre channel.
With surround sound miking techniques, we simply set up microphones to capture sound for a specific surround sound channel and then pan those mics to their respective channels. Of course, mixing the levels of these mics is requires, but the miking technique will set us up for a successful surround sound record.
Note that the surround sound miking techniques listed in this article are just techniques. They can and should be experimented with to get the best results for your project.
The most common surround sound format is 5.1, a standard from the International Telecommunications Union (ITU).
5.1 Surround calls for 6 loudspeakers in the following positions:
|Channel Order (SMPTE Standard)||Channel Name||Speaker Position|
|1||L: Front Right||
|2||R: Front Left||
|4||LFE: Low Frequency Effects||
|5||Ls: Surround Left||
|6||Rs: Surround Right||
Note that, in an ideal world, all loudspeakers are to be positioned at an equal distance from the listener. Note, too, that all loudspeakers are to be the same except for the LFE channel, which is a subwoofer that handles frequencies between 3 Hz – 120 Hz.
Of course, any surround sound standard is highly dependent on the listener being in the “sweet spot” where all speakers are equidistant. This is not practical in the vast majority of scenarios and is [nearly] impossible if there are two or more listeners in the environment.
With that being said, the 5.1 standard is excellent for surround sound playback.
So now that we understand the basics of surround sound, let’s look at the best surround sound miking techniques. Each of these techniques will get us very close to a natural surround sound recording of any environment.
In this article of the 4 best, we’ll focus on miking techniques that will effectively get us to a 5.1 standard. Therefore, there need to be at least 5 microphones in the array (L, R, C, Ls, Rs) to capture the directional audio channels.
As for the LFE, we rely more so on the low-end frequency response(s) of the microphones to capture the low-end.
To learn more about microphone frequency response, check out my article Complete Guide To Microphone Frequency Response (With Mic Examples).
1. OCT Surround
What is the OCT surround miking technique? OCT Surround is a surround sound miking technique with an OCT front array (L, C, and R) with two rear mics (Ls and Rs). The front cardioid mic (C) is 8 cm ahead of the supercardioid L and R mics. The rear cardioid mics point opposite to C and are 48 cm back and spaced 60-120 cm apart.
The OCT (optimized cardioid triangle) front array provides us with a flexible front stereo image in our surround sound format. When the L and R supercardioid microphones are positioned closer together, the image will sound narrower while, conversely, if the L and R mics are further apart, the image will be wider.
This is also true of the Ls and Rs microphones. The flexibility of this technique makes it a top pick for true surround recording. Depending on the acoustic profile of the environment, we may want to position the mics closer together or further apart. Listen for phasing issues and use your best judgment!
For more information on cardioid and supercardioid polar patterns, check out my articles What Is A Cardioid Microphone? (Polar Pattern + Mic Examples) and What Is A Supercardioid Microphone? (Polar Pattern + Mic Examples).
2. Corey/Martin Tree
What is the Corey/Martin Tree miking technique? The Corey/Martin Tree is a surround sound miking technique. Subcardioid mics face left, right and centre while cardioid mics point upward in the back. The left and right mics are 120 cm apart. The centre mic in the middle, 15 cm forward. The back mics are 30 cm apart and 60 cm behind the front pair.
The Corey/Martin Tree technique has a fairly wide front array. However, the sub cardioid patterns of the L and R mics allow these microphones to capture more sound from the rear and act to capture more crossfeed (sound from the left in the right channel and vice versa).
At these widths (120 cm – 180 cm), the phasing between the L and R channels will not be overbearing.
The microphones to the rear are relatively close together, giving a rear surround image that sounds more directly behind the listener than wider-spaced rear mics. Play around with angling of the rear microphone for a wider rear image.
For more information on the subcardioid microphone polar pattern, check out my article What Is A Subcardioid/Wide Cardioid Microphone? (With Mic Examples).
3. Fukada Tree
What is the Fukada Tree miking technique? The Fukada Tree is a 7-mic surround sound technique. The front array has 3 cardioid mics (L, C, and R). L and R are spaced 1.8 m apart and point 45° away from centre. C is centred but 1 m forward. A rear pair of cardioids mirror the front L and R. Omni mics are set 1 m left of L and 1 m right of R.
As seen in the above diagram, the Fukada Tree is a very wide surround sound technique. If you have the space to set up the Fukade Tree, it has the potential to provide a very expansive image for the listener.
This technique can be used to capture incredibly spacious ambient recordings. It also excels in capturing audience noise along with a detailed stage sound in live performances.
The omnidirectional microphones at the far left and right of this set up can be mixed to your liking between the stereo and surround left and right channels, respectively. Mixing more omni signal will yield a wider image and bring the rear sound a bit closer and outward from the listener’s perspective.
For more information on the omnidirectional polar pattern, check out my article What Is An Omnidirectional Microphone? (Polar Pattern + Mic Examples).
What is the INA-5 miking technique? The INA-5 is a 5-cardioid-mic surround sound miking technique. The center (C), left (L), and right (R) mics point outward and are positioned 7″ from a centre point to the front, left, and right, respectively. The LS and RS mics are positioned 24″ behind the L/R and are 24″ apart, pointing outward.
The INA-5 (Ideale Nieren Anordnung, which is German for “ideal cardioid arrangement”) is quite a compact stereo miking technique, taking up less than 6 square feet. This small footprint makes the INA-5 a great choice in small and large rooms as well as in the outdoors.
Compact as it is, the INA-5 produces a broad surround sound image that is well balanced between the front/back and the left/right.
The following miking techniques are commonly used to capture surround sound images, though they are not made up of 5 microphones. With these techniques, we must get a bit more creative with the surround sound audio mixing.
What is the IRT cross miking technique? The IRT cross is a surround sound miking technique consisting of 4 cardioid mics positioned in a 20-25 cm (8-10 in) square formation and pointing outward toward their respective corners. The IRT cross resembles back-to-back near-coincident stereo pairs.
What is the Hamasaki square miking technique? The Hamasaki square is a surround sound miking technique with 4 bidirectional mics arranged in a 1.8 – 2 meter (6 – 6.5 ft.) square. The mics point left to right so that their null points face the main sound source. The Hamasaki square captures ambience while minimizing direct sound and reflections.
To learn more about the bidirectional polar pattern, check out my article What Is A Bidirectional/Figure-8 Microphone? (With Mic Examples).
What is the double mid-side array? The double mid-side array is a surround sound miking technique with two cardioid mics and one bidirectional mic positioned coincidentally. One cardioid points to the front and the other points to the back. The bidirectional mic is placed with negative polarity at 90° and positive polarity at 270°.
Full List Of Common Surround Sound Miking Techniques
Here is a list of common surround sound miking techniques (with links to their descriptions on my Microphone Terminology/ Glossary (With Definitions) page:
- Ambisonic Array (when formatted to surround sound)
- Ambisonic Microphone (when formatted to surround sound)
- Ball Boundary Technique
- Cardioid Trapezoid
- Corey/Martin Tree
- Double Mid-Side Array
- Double ORTF Array
- Fukada Tree
- Hamasaki Surround System
- IRT Cross
- OCT Surround
- Omni+8 Surround
- Polyhymnia Pentagon
- Spherical Microphone Array
- Wide Cardioid Surround Array
What is a stereo microphone? A stereo microphone is a single microphone that outputs two mono signals (from two diaphragms) that can be mixed into a stereo image. The diaphragms are positioned in a coincident stereo pair within the body of the microphone and are designed to capture sound in stereo.
To learn more about stereo microphones, check out my article Do Microphones Output Mono Or Stereo Signals?
What is stereo miking? Stereo miking refers to any microphone placement technique that will yield a stereo audio image. Stereo miking requires at least two microphones (or a single stereo microphone). These mics are positioned in such a way so they pick up a left side and right side. The mic signals are then panned left and right in the mix, respectively.
For a deeper read into stereo miking techniques, check out my article Top 8 Best Stereo Miking Techniques (With Recommended Mics).