Loon Phase Diffuser

Blur — the main depth control

Blur is the global macro that scales every bin's rotation angle. At 0% the plugin is bit-transparent — the per-bin angles exist but are multiplied to zero, so nothing happens. As Blur rises, bins gain rotation according to the drawn curve weight at their frequency and the low-frequency protection ramp.

• 0–25% — Subtle. Barely perceptible in a full mix, useful as a glue or spatial widener on a bus. Safe on any source.
• 25–60% — Moderate. Transients soften noticeably. Reverb sends and room mics open up. Good starting range for pads and textures.
• 60–100% — Strong. The source blurs into a wide, diffuse wash. Best on sustained material — pads, strings, noise, synth textures — where this is the desired effect.

The sub-bass is always protected regardless of Blur level — a hard-coded ramp keeps bins below 120 Hz at zero rotation, reaching full depth by 350 Hz. No bass energy is lost at any Blur setting.

The Blur Curve — per-frequency depth

The 512-point drawable curve is a per-band multiplier for Blur. A flat line at 1.0 (default) means Blur applies uniformly everywhere above the bass ramp. Draw it lower in a band to protect that frequency from diffusion.

• Draw freehand — click and drag on the canvas. The X axis is frequency (log scale, matching the spectral analyser behind it). The Y axis is depth (0 = no diffusion, 1 = full Blur).
• Preset shapes — Flat / Rising / Falling / Mid Bell / High Hump / Rising Tiers. Access via the shape selector. Good starting points before customising.
• Brown randomizer — bounded random walk. Creates smooth spectral mountains and valleys. Good for organic, non-uniform diffusion.
• Smooth randomizer — interpolated with soft-clip shaping. Softer than Brown, no harsh curves.
• Flip — mirrors the curve vertically (1−y). A rising curve becomes falling, a high hump becomes a valley.
• Reset — restore flat 1.0 default.
• Undo/Redo — 5-step history. All tool actions and drawn changes are captured. Standard keyboard shortcuts if the plugin has focus.

Stereo Link & decorrelation

The Stereo Link toggle controls whether the L and R channels share one set of per-bin phase angles or get independent sets.

• Link On (default) — Both channels rotate by the same angles. The diffusion is mono-compatible: summing L+R produces the same energy as the input. Good for master bus, reverb sends, or anywhere mono compatibility matters.
• Link Off — Each channel draws its angles from an independent seed. The two channels rotate completely differently across every bin, creating a wide stereo image that sounds enormous on headphones. Check mono compatibility — some partial cancellation is expected and is by design. Safe for headphone-optimised content and background layers.

The sub-bass protection ramp applies to both channels independently in all Link modes — bass diffusion is always prevented.

Drift — organic shimmer

At 0% the phase angles are perfectly static — the exact same rotation every block, no movement, no warble. Drift adds a very slow per-bin random walk: each angle wanders within a bounded range (±π), sized so it takes about 8 seconds to traverse its full range.

• 0% — Completely static. Byte-identical to no-drift processing. Use when you want a fixed, predictable spatial character.
• 10–30% — Subtle shimmer. On long pads and room sounds, the diffusion character evolves slowly — the sound seems to breathe. Not perceptible as motion, just as life.
• 40–70% — Audible movement. The spatial character changes over time like a slowly rotating room. Good on sustained textures and drone layers.
• 70–100% — Faster walk. More obvious motion. Starts to resemble a very slow chorus or flanger. Best on deliberately evolving texture material.

When Link is on, R replays L's walk (same drift path, same mono sum). When Link is off, each channel walks independently — the stereo image evolves differently on each side, which is even wider.

Size & latency

Size sets the FFT window length. Larger windows resolve lower frequencies more distinctly and produce a longer, more enveloping wash — but at the cost of more latency. The host compensates automatically via PDC (plug-in delay compensation).

• Tight (1024 samples) — ≈23 ms at 44.1 kHz. Lowest latency. Good for live or low-latency studio use. Slightly less resolution in the sub-bass, but the bass ramp protects that area anyway.
• Soft (2048 samples) — ≈46 ms. Default sweet spot for most studio sessions. The phase rotation is more distinct across a wider bin range.
• Wash (4096 samples) — ≈93 ms. Maximum smearing. Long diffusion tails. Best for ambient, drone, or film work where transient softening is the explicit goal and latency is acceptable.

Size is not automatable — switching it re-prepares the engine off the audio thread and re-reports latency to the host. Set it before the session rather than mid-playback.

Reseed

The Reseed button draws a completely new set of pseudo-random per-bin angles from fresh seeds. Everything else stays the same — the curve, Amount, Drift, Size — only the fingerprint of which bin gets which angle changes.

Use Reseed when: a partial in your source material happens to land near a phase relationship that causes an unwanted resonance or hollow quality. Reseed moves every bin to a new angle, typically resolving the artefact in one or two tries. The new seeds are saved with the preset, so your chosen fingerprint restores on load.