s3g-dsp

Panner VBAP

s3g Panner VBAP is a direct speaker panner, not an ambisonic plugin. It steers each source through valid speaker pairs or three-speaker facets derived from the selected layout.

Panner VBAP with four source points against a Cube 17 speaker geometry and its solver topology.

Workflow

  1. Insert Panner VBAP on a REAPER track with the required source inputs and enough channels for its 64-channel output bus, then select or load the speaker layout and confirm its active speaker count and output order.
  2. Route the active output lanes to the matching main speakers, directly or through a speaker-array utility chain, then begin playback.
  3. Move sources in FIELD while watching the yellow solver pairs and facets used by the selected layout.
  4. Check transitions across facet boundaries, around the poles, and through any unsupported elevation region before final calibration.

Signal Shape

source inputs
-> source direction / distance / gain
-> matching speaker pair or three-speaker facet
-> normalized VBAP vector gains and pole support
-> source distance rolloff
-> speaker outputs 1-64

Only the active speaker count writes sound. Unused output lanes are silent.

Vector-Base Amplitude Panning

VBAP represents the source direction with a local speaker basis. Flat layouts use two-speaker pairs; three-dimensional layouts use triangular facets. The solved gains are power-normalized, producing focused directional steering and controlled handoffs as the source crosses from one pair or facet to the next.

If no valid pair or facet contains a direction, the fallback selects the nearest real speaker direction. Pole-cap blending stabilizes motion at extreme elevation rather than allowing a weak or incomplete facet to dominate.

Solver Topology

The faint yellow overlay draws the pairs and facets used by the VBAP solver. It is not a decorative nearest-neighbor mesh. Imaginary solver speakers may be added where the real layout does not close cleanly; they support the solve but never create output channels.

Flat layouts receive silent imaginary top and bottom speakers. Partial three-dimensional layouts, such as quad plus overheads, can also receive support points and pole-cap blending near +90 and -90 degrees.

Speaker and Source Distance

VBAP builds its solver from normalized speaker directions. Stored speaker DST affects the field drawing but not the pair or facet gain solution. A source at DST 1 can therefore point exactly toward a farther Cartesian cube speaker while appearing inside its marker. See AED Distance and Layout Shape for the preset geometry.

Source DST still controls overall rolloff and the selected IN behavior. For flat layouts, elevation produces a smooth attenuation away from the speaker plane. When a layout has no real lower speakers, downward motion preserves the VBAP distribution and rolls toward silence at -90 degrees.

Field, Mixer, and Design

FIELD shows sources, speaker geometry, and the yellow VBAP topology. MIXER provides source gain, mute, solo, and output level. DESIGN edits or imports speaker positions. These pages and the custom-layout JSON format are shared with Panner Layout; see Pages, Design Page, and Custom Layout JSON.

The host project stores the selected TOP, SIDE, or 3/4 view together with manual rotation and zoom.