Ambi Field / Bus Effects

Ambi field and bus processors work on complete ambisonic signals without breaking their channel relationships. Single-field processors expect one encoded field. Group processors treat each 16-channel third-order ACN/SN3D block as one locked feed.

Workflow

1. Choose a processor and insert it on a correctly routed Ambisonic track whose width matches the single field or grouped fields. For a group processor, route each complete 16-channel 3OA feed into its assigned input block.
2. Follow a single output field with an ambisonic decoder. Additional Ambisonic effects may be placed before that decoder when their supported order and channel count match the field. For grouped outputs, apply compatible effects within each 16-channel field and route each field to its own decoder, or mix the groups to one field before its compatible effect chain and decoder.
3. Establish a neutral field or group state, then send audio through the complete chain.
4. Shape matrix connections, node relationships, rotation, or depth while listening through the decoder.

Plugins

• Ambi Depth 16: single-field 3OA depth, focus, air, tail, low-body, width, and output controls.
• Ambi Matrix Group 64/128: matrix mixing between four or eight 3OA feeds.
• Ambi Mixer Node Bus 128: node/cursor mixing for up to eight fixed 3OA feeds.
• Ambi Transform Group Rotate 64/128: coherent rotation per 3OA group, with relationship offsets across groups.
• Ambi Transform Group Depth 64/128: depth and order shaping across four or eight 3OA feeds.

Ambi Matrix Group Model

The matrix processors route one complete 3OA group into another complete 3OA group. A crosspoint routes all 16 channels together, preserving the spatial encoding while allowing bus-level mixing between feeds.

• SHAPE: generated gain pattern. Choices include flow, pulse, chase, swirl, scatter, and hold.
• MODE: free-running or transport-synced timing for animated patterns.
• DPTH: how strongly the generated pattern enters the matrix.
• SPRD, MOT, and related pattern controls: how wide, animated, or patterned the active matrix layer becomes.
• Gray matrix cells show the manual ceiling. Green activity shows the current pattern inside that ceiling. This is routing-state color, not signal level; see Interpreting Color.

Ambi Mixer Node Bus Model

The Ambi Mixer Node Bus combines as many as eight complete 3OA feeds on one 128-channel REAPER track. Node 1 uses channels 1-16, node 2 uses 17-32, through node 8 on channels 113-128.

The mixer defaults to a flat relationship plane. With LOCK Z checked, all nodes and the cursor stay at Z = 0, so the top view becomes the normal mixing view. Uncheck LOCK Z when a mix needs full 3D node placement and side or 3/4 camera work.

• NODE COUNT: number of 3OA source blocks used by the mixer.
• X, Y, Z: node position in the relationship field. Z is locked at zero while LOCK Z is checked.
• RAD: node radius, or how far from a node the cursor begins fading that node in.
• FOC: node focus, or the curve from the radius edge to the node center. Lower values are broader; higher values are tighter.
• INFL: how strongly cursor position affects node gain.
• CURSOR: movable emphasis point for fading between nodes by position.

Ambi Transform Group Rotate Model

Rotate applies a coherent ambisonic rotation to each group. It is useful when several 3OA beds or stems need related movement without building separate automation for every feed. Spread, tilt, and twist describe relationships between complete ambisonic fields rather than tearing one field apart.

• YAW: horizontal rotation for all groups.
• PIT: vertical pitch/elevation rotation for all groups.
• ROL: roll around the front axis.
• SPRD: yaw offset spread across groups.
• TILT: pitch offset distribution across groups.
• TWST: roll offset distribution across groups.
• WID: order-width trim for the rotated groups.

Ambi Depth Model

s3g Ambi Depth 16 is the single-field version. Center is neutral. Positive values push the field farther and softer by reducing higher-order spatial detail and applying optional air damping. Negative values push toward a nearer, more present image. The distance tail adds a diffuse FDN layer behind positive depth settings.

• DEP: near/presence to far/soft depth transform.
• FOC: diffuse to focused order behavior.
• AIR: negative values add presence; positive values add distance damping.
• TAIL: a diffuse distance tail that blooms behind positive depth settings.
• LOW: low-body compensation or reduction.
• WID: order-width trim.
• OUT: final output gain.

Ambi Transform Group Depth Model

s3g Ambi Transform Grp Depth 64/128 applies the same depth model to four or eight lane-locked 3OA feeds. SPRD distributes bipolar depth offsets across groups, while the field display shows each group's depth position, air haze, and distance-tail wake.

• DEP: shared near/far depth transform.
• SPRD: bipolar distribution of depth offsets across groups.
• FOC, AIR, TAIL, LOW, and WID: shared order and distance shaping applied per group.

Routing

s3g Ambi Depth 16 is intended for one 3OA field on a 16-channel track. The 64-channel group versions are intended for four 3OA groups. The 128-channel group versions are intended for eight 3OA groups. In REAPER, set the track channel count before inserting the plugin so the pin connector matches the intended width.

For non-ambisonic group and node mixers, use Multichannel Bus Mixing / Routing.