11/01/15

PRINCIPLES OF THE WIDE CARDIOID SURROUND ARRAY TECHNIQUE

The Wide Cardioid Surround Array (WCSA), introduced by Mikkel Nymand, provides equal timbral qualities, a high degree of envelopment and good low-frequency properties.
When choosing the right microphone array for a specific acoustic surround sound capture, the distance and angling between microphones and choice of microphone directionality must be considered.

To obtain the desired sound character (and for enhancing the listening position from a sweet spot to a sweet area), the five signals should be decorrelated. This means the microphones must be placed at an adequate distance from each other. On the other hand, the signals should not be too different (distant) from each other. If this happens, the resulting sound will not be coherent.

Omnidirectional microphones are often preferred for spaced arrays. This is due to their natural sound color and their ability to blend direct signals with room timbre. Wide cardioids (also named sub-cardioids) have a slightly more directional quality, which gives more ambience control and improved front imaging and localization accuracy.

This array, initiated by Geoff Martin and Jason Corey, uses an omnidirectional and a cardioid to create a wide cardioid characteristic. By focusing on preventing interchannel interference, the microphone pairs were spaced L-C 60 cm (24 in), R-C 60 cm (24 in), Front-Rear 60 cm (24 in) and LS-RS 30 cm (12 in). The rear mics used were upward-aiming cardioids to capture height information.

DPA Microphones adapted this array to use five identical wide cardioid microphones (matched within a very narrow tolerance of ±1 dB on frequency response and sensitivity). Choosing five identical microphones instead of just a specific microphone type keeps the blend natural and leads to a more authentic and uniform reproduction of all channels.

After intense listening sessions and numerous practical try-outs in different recording applications (symphonic music, modern jazz, PA / Live, pop concerts and ambience recording) the adaptation tends to recommend a larger spacing, especially of the rear channels. This array creates an intense, dynamic and enveloping sound character. 

The recommended distances are:

L-C 60-75 cm (24-30 in)

R-C 60-75 cm (24-30 in)

C-LR 20 cm (8 in)

Front-Rear: 150-200 cm (59-79 in)

LS-RS: 120-150 cm (47-59 in)

For wide ensembles (or large array-to-source distances), try expanding this array with two left / right omnidirectional outriggers to benefit from the pressure transducer's low-frequency pick-up. These microphones are blended with L / R from the array at appropriate level, offering a beautifully coherent, precise and rich surround sound image. 
 

Suggested microphones

If you want to try this setup, we suggest:

d:dicate™ 4015A Wide Cardioid Microphone

d:dicate™ 4015C Wide Cardioid Microphone, Compact

d:mension™ Surround Kit with five d:dicate 5015A, clips and windscreens in Peli case

Surround / Decca Tree Mount

 

EXPLORE FURTHER

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