encoder

The encoder places a mono or stereo track in the ambisonic field and moves it along a path you draw on the sphere. How fast it travels can follow the input: silence parks the source, loud material moves it. It is the first plugin on a track: it takes one or two channels in and gives an ambisonic field out.

Its window is the one every bambi plugin has, described in the tutorial. What is the encoder’s own is its three tabs.

trajectory

The path’s shape. The row at the top chooses a kind: orbit, lissajous, wave, arc, spiral, or custom. Under it are that kind’s own settings, and each can be automated and modulated, so a path can breathe with the music.

convert to custom turns the path into nodes you edit on the sphere:

• drag a node to move it, and its handles to bend the curve; alt-drag a handle to make a corner;
• click the curve to add a node exactly there;
• shift-click a node to delete it.

The kind you converted from is kept, so you can go back to it.

transform

Where the path sits and how it turns: yaw, pitch and roll, each beside a rate that keeps it turning, and extent. At 1 the path is as drawn, at 0 it closes onto its own centre, and at 2 it opens out through the far side.

source

• The input: sum puts one point on the path. mid/side puts the mid on the path and the side either side of it, spread apart. stereo puts left and right on the path, offset apart. input trim sets the level before the features hear it.
• motion: speed is how fast the source travels, and displace is where on the path it sits. direction and mode (wrap, ping-pong or once) say what happens at the ends.
• render: width, how far the source spreads over the sphere, and the width range modulation may move it in.

three things to try

1. The kick nudges on every hit. Choose arc, click displace, click the cell under attack, and drag it up.
2. The pad opens up when it rings. Click width, click the cell under tonal, and drag.
3. It drifts slowly, and faster when it is loud. Set speed to a small value, then click speed and give it depth under level.

what it builds on

The encoding follows the ambisonics literature on the foundations page: the spherical harmonics, ACN ordering and SN3D normalisation, and the max-rE weighting its width is drawn with.