Processor Spectral

s3g Processor Spectral 8ch/24ch is a spectral mesh for fixed-width multichannel tracks. Its 8 or 24 processing nodes analyze synchronized FFT frames, apply local spectral texture, and transport material through the topology network before resynthesis.

This makes the point graph part of the audio path rather than only a source of per-lane parameter offsets. Use Processor Spectral when captured or live frequency material should move between channels; choose Spectral Spray for lane-local FFT processing, Wave Geometry for direct waveform shaping, or a Macro effect for a smaller shared control set.

Workflow

1. Insert the 8-channel or 24-channel build on a matching REAPER track, then route source lanes with the FX pins and internal patch matrix.
2. Route the result to the main speakers, a direct panner, or a stereo or quad fold-down, then begin playback. Another effect may precede that destination when its build matches the current bus width.
3. Set the local spectral engine and wet mix before introducing cross-node transport.
4. Raise AMT and shape nearest-neighbor, radius, centroid, velocity, dispersion, and damping relationships.
5. Capture or freeze useful material, then animate the graph and balance feedback, repeat history, and output level.

Signal Flow

1. REAPER audio enters the patch matrix, which injects sources into the fixed 8- or 24-node mesh.
2. Each node analyzes overlapping FFT frames and applies its local spray, smear, damage, phase, and frequency-window processing.
3. CAP can replace the local source spectra, and FRZ blends those captures into the material presented to the mesh.
4. The topology graph selects nearest-neighbor routes. Its propagation memory can deliver each neighbor spectrum immediately or after a distance-derived fractional number of FFT frames.
5. RPT history and feedback operate on the routed field before resynthesis.
6. MIX blends the latency-aligned dry and wet paths, and OUT sets final level.

Engine Controls

• BINS: spectral spray range.
• DRFT: bin drift and movement across the spectral field.
• HOLD: decay of peak spectral memory.
• FRZ: blend into a true spectral capture. Engaging it captures automatically; CAP replaces the capture and CLR empties it.
• FDBK: bounded recirculation of the routed spectral field.
• SMR: spectral smear.
• HOLE: dropout cells in the spectral path.
• PHAS: phase blur.
• DMG: broken-bin and dropout damage.
• RPT: retrieval from a spectral history of up to 32 frames.
• LO and HI: lower and upper limits of the processed frequency window.
• TRANS: preservation of transient attacks through the spectral process.
• TILT: frequency tilt across the processor.
• MIX: global dry/wet mix.
• OUT: final output gain.

Topology

The topology panel uses the same point language as Processor Delay and Processor Wave Geometry, but here the relationships route spectral material between nodes.

• AMT: master depth for topology influence and spectral transport. At zero, every node remains a local spectral processor with no cross-node transport.
• NN: number of actual nearest-neighbor destinations for each node.
• RAD: reach and distance weighting of the neighbor paths.
• CENT: blend into a normalized whole-field spectral pool.
• TWIST: braids low and high frequency regions along opposing routes.
• FLARE: biases the frequency regions sent through the mesh.
• SHAPE, displacement, and motion controls move the nodes and therefore change the routing relationships.

The topology window has two pages:

• TOPO: point network plus topology heatmap view. Graph edges show current transport activity.
• SONO: one-second, grayscale post-processing sonogram for the lane outputs.

The sonogram is a visual analyzer for the plugin output. It is not an additional audio effect, and it does not change the spectral processing.

Propagation

The propagation panel turns the mesh from an instantaneous crossfeed network into a traversable spectral space. Travel time follows the current smoothed distance between connected nodes, so moving or reshaping the graph also bends the timing of the routed field. The whole-field CENT path remains immediate.

• VEL: propagation speed. At 100%, neighbor routing is instantaneous. Lower values reveal progressively longer travel, reaching roughly 127 FFT hops at the slowest, longest route.
• DISP: frequency-dependent travel. Positive settings let low bins lead while high bins arrive later; negative settings reverse that relationship.
• DAMP: distance- and frequency-dependent loss along a route. Raise it to make long journeys quieter and darker.

Moving markers on active graph edges show the current propagation phase. They are transport feedback, not extra modulation, and become stationary at the instantaneous VEL setting.

Patch Matrix

The patch matrix injects REAPER inputs into the mesh; it does not determine its node count. All 8 or 24 nodes remain available as transport destinations, so a node with no direct input can still receive and output wet spectral material from its neighbors or the centroid pool. Use the matrix when the track is wider than the source material or when one input should seed several nodes. The 24-channel build uses a compact matrix so all nodes remain visible.

Realtime Buffer Floors

Spectral processing concentrates FFT-hop work into particular audio callbacks, so the smallest stable buffer depends on channel count and sample rate. The strict release profiles cover the 8-channel build at 48 kHz with 64 frames or more and at 96 kHz with 128 frames or more. The 24-channel build is covered at 48 kHz with 256 frames and at 96 kHz with 512 frames. These are tested release floors, not guarantees for every computer or project; dense routing, other effects, power mode, and host scheduling still matter. Smaller buffers remain available for deliberate testing but are not claimed as realtime-safe configurations.

Performance Example

Patch a chord into one node, raise AMT and NN, then engage FRZ while the chord is sounding. Mute the source and the captured spectrum can continue through the mesh. Lower VEL until each connection becomes a distinct spectral arrival, add positive DISP for a low-to-high unfurling, and use DAMP to keep distant echoes behind the source. CAP replaces the frozen material, RPT recalls earlier frames, FDBK extends circulation, and CLR empties the capture.