Ambi Decoder Object

s3g Ambi Decoder Object 64 renders first- through seventh-order ACN/SN3D to a curated speaker layout, then blends that complete field decode with one moving object path derived from the input's first-order directional energy. The object path can use VBAP, LBAP, or DBAP over the same speaker positions.

This is a content-derived emphasis decoder, not an object-audio metadata decoder. It does not receive named objects or recover isolated sources from a mixed field. Instead, it estimates the currently dominant direction and uses a confidence gate so diffuse or ambiguous material contributes less to the object branch.

Workflow

1. Insert s3g Ambi Decoder Object 64 after the encoded source and any Ambisonic processing on a 64-channel track. Match ORDER to the source, then choose LAYOUT, field MODE, and WGT.
2. Route each active output lane to the corresponding physical speaker in the selected layout.
3. Choose VBAP, LBAP, or DBAP from OBJECT, then raise BLEND while audio is playing.
4. Set CONF and XOVR so the object branch follows useful directional events, use SMTH to control its motion, and balance FIELD, OBJ, and OUT.

Signal Flow

1. The complete active-order field enters the selected speaker decoder matrix.
2. A separate analysis path high-passes the first-order W, Y, Z, and X components and estimates a dominant active-intensity direction.
3. CONF gates the omnidirectional cue when the directional estimate is weak, while SMTH stabilizes the estimated direction.
4. The gated cue is panned as one object through the selected direct-panning method over the same speaker coordinates.
5. BLEND crossfades the field and object branches after their independent gains; OUT controls the complete result and unused output lanes are silenced.

Derived Directional Cue

The object analyzer uses the first four ACN channels in W, Y, Z, X order. Products of W with the three directional components form the direction vector. Directional magnitude relative to W supplies a confidence estimate, and CONF defines where a smooth gate begins opening. Raising CONF makes the object branch more selective; at very high settings, only strongly directional moments pass it.

XOVR high-passes the four analysis components before direction and confidence are calculated. It does not high-pass the complete field branch. This lets low-frequency energy stay in the speaker decode without making the derived object direction chase bass-heavy or weakly directional content.

SMTH is direction smoothing, not audio delay. Low-confidence directions receive additional stabilization, so ambiguous passages move more slowly than clear directional events at the same setting.

Object Methods

The method affects only the derived object branch. MODE and WGT continue to shape the complete field branch, so changing OBJECT does not replace the underlying ambisonic decode.

Layouts and Field View

The layout menu shares the Speaker decoder's curated geometries, including Quad, Cube 8, Cube 17, Cube 41, Dodeca 12, Icosahedron 20, Octo Ring, Dome 24, Dome 25, LPAC 41, SRST 25, Quad+OH, and Sphere 24. The active output count follows the selected layout.

CUSTOM generates a full-sphere field using the active count inherited from the previously selected layout. Unlike Ambi Decoder Speaker, the Object editor does not provide a count control, measured custom-speaker editing, or per-speaker trims. Choose a curated layout first when a particular count is required, and use Speaker when the rendering matrix must follow individually entered positions. The field view supports Top, Side, and three-quarter inspection, view rotation, and zoom. Camera changes are visual only and are saved with plugin state.

Controls

INIT restores Sphere 24, EPAD, 3OA, MAXRE, VBAP, 35% Blend, 0 dB Field and Object gains, 18% Confidence, a 250 Hz analysis crossover, and 25 ms smoothing while preserving the current OUT trim.

Order and Routing

The full field branch uses every active channel for the selected order. The object analysis always uses only the first-order W/Y/Z/X components, even at higher orders. Match output lane numbers to the selected layout's speaker order before connecting amplifiers or hardware outputs.

Limits

A diffuse field, multiple simultaneous directions, or a mix whose first-order energy cancels can produce a weak or unstable object cue; the complete field branch remains available for exactly that reason. Object emphasis can also change level and localization, so compare at restrained BLEND and use the independent gains rather than assuming the two branches are loudness matched.