[Len Moskowitz]

We’re probably all familiar with the ability to edit tracks in the time and frequency domains.

Because we’re used to recording with traditional mono microphones that throw away all spatial information, we’re not aware that – if instead we use microphones that preserve all of the spatial information – we can also edit in the spatial domain.

Spatial Domain Editing

Did you ever really want to somehow remove an audience cough in an otherwise quiet classical music location recording?

With a higher-order ambisonic recording and well-designed plugins, you can use spatial filters to remove sounds coming from specific directions, including the cough from the gentleman in seat 4 of row 5, on the left side of the audience.

Here’s an example of how to remove an audience cough from a higher-order ambisonic recording using Blue Ripple’s spatial audio plugins:

(Thanks to Jim Slagle for this video. Jim records with Core Sound’s OctoMic.)

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Details about the video:

It uses the O3A plugin suite from Blue Ripple Sound. The owner/author of Blue Ripple Sound is Richard Furse (as in FuMa – Furse/Malham).

The DAW is Reaper. The track he’s working on is called “B-format in”. The processed track is called “O3A”.

The track is in second-order B-format, 9 channels.

He uses two instances of the O3A Flare plugin to visualize audio spatials – one on the input and one on the output. The upper one is displaying the raw B-format track. The lower one is displaying the post-masking track.

The O3A Spatial Mask plugin is set to mask at the spatial location he’s identified in Flare. He sets the time the mask is applied with the upper timeline envelope control. It’s bypassed with the line up and active with the line down.

[Phil Koenig]

This is a very cool tool.  It appears to be far superior to using a spectral edit, though it’s a little hard to tell in this example because the cough is masked by the choir.