Question: How can the BP3600 microphone be used in immersive audio applications?

Answer: The Audio-Technica BP3600 is a near-coincident array microphone designed for immersive audio applications. The eight 12 mm hypercardioid capsules offer a very consistent polar pattern, even at high frequencies. The microphone’s elements offer a significantly high front-to-total ratio (FTR), which is critical to ensuring that pickup is isolated to sound in front of each element, not the rear. With these attributes, the capsules provide a very natural and accurate capture of an ambient sound field, making them an optimal choice for this kind of array design.

As with any capturing of sound, the target playback system must be considered. The BP3600 can, of course, be targeted to the standard 5.1.4 surround sound speaker setup, which includes front channels (front left, front center, front right), rear channels (rear left, rear right), height channels (height front left, height front right, height rear left, height rear right) and a sub or LFE channel. With this standardized playback system the user can route the BP3600’s four upper elements to the four height channels and the four lower elements to the lower surround channels. This allows the immersive capture to be routed directly to those speakers without the decoding or latency-adding processing that other immersive microphone options, such as ambisonics, require. But the BP3600 can also be used with a variety of playback systems, so, depending on the application and playback system, the workflow may differ.

Broadcast Workflow

The broadcast workflow of the BP3600 utilizes the real-time solution as described above. In a matter of minutes, the BP3600 can be deployed into a diffuse sound field to capture an audience or crowd. Other BP3600 applications include capturing acoustic characteristics of a concert hall or other live venue, or the natural sounds in a recording space. The eight channels can be routed directly to the immersive playback channels for a broadcast or encoded with the video sources to be sent out to the broadcast destination. The BP3600 can be used as the single capture device for VR applications or quick deployment applications. Alternatively, the BP3600 can be used in conjunction with other popular production microphone devices, such as shotgun microphones, and close microphone devices, including lavalier, announcer headsets, boundary, or handheld microphones. A broadcast mixer can combine all of those signals to create an immersive experience that allows the listener to feel both close to the action and part of the audience in the space where the event is happening.

Postproduction Workflow

The postproduction workflow of the BP3600 allows the user to capture an immersive sound field as they would in a real-time application, but also add processing for a finished, edited deliverable. Immersive audio applications commonly consist of stationary sound beds and movable objects. The BP3600 can be used as a single sound bed capture device or alongside other stationary devices to recreate consistent sounds, such as ambient noises and crowd noises, or even to give a sense of the acoustical attributes of a space. These signals are used to create the sound bed channels. The objects, however, may be moved around the sound field for playback to give a better sense, say, of a person who wanders about while talking or singing or of a motorbike that goes whizzing past the camera. Moving these objects in the mix allows the listener’s brain to establish clearer localization of the sound. The BP3600’s eight discrete audio channels can be used as the audio bed while creating a Dolby Atmos mix or other immersive deliverables.

If you have additional questions about the BP3600 or other Audio-Technica microphones, please contact the Audio Solutions Team for assistance.