The Focal Point User Guide

The Focal Point is an eight-stage spectral motion processor for sound design, production, and creative tonal movement. It is not a mastering EQ. Use it to build resonant texture, animated filter movement, vocal/formant character, stereo shifts, rhythmic response, and tape- or vinyl-style instability.

At its simplest, it can be one resonant filter. At its deepest, it can be eight filter stages moving in relation to each other, driven by internal Motion, Sidechain, and Drift. You do not need to use all of that at once.

Start with a clear static shape. Add movement only after the sound has a reason to move.

Quick Start

Enable one stage and choose a filter type.
Set Focus, then use the stage's Octave Offset or Spread to place it.
Raise Resonance until the sound has the amount of edge, ring, or character you want.
Add a second stage only when the first one has a job.
Introduce Motion for movement. Use Sidechain when you want the sound to react to audio, and Drift when you want pitch/time instability.
Use Filter Mix, Output, A/B, and Bypass to make the final call at a fair level.

The Eight Stages

The Focal Point contains eight filter stages in series. Each stage can be enabled independently, assigned a filter type, shaped statically, and given its own motion or sidechain response.

Selecting a stage and turning it on are separate actions. Click a stage tab once to select it; then use its power control to engage it. This prevents an accidental change to a stage when you only mean to inspect it.

The response graph shows the combined result of the active stages, alongside their individual curves. Drag a stage node horizontally to change its Octave Offset, vertically to adjust its primary filter parameter, or diagonally to do both. Double-click returns a control to its default.

Filter types

Each stage offers ten types:

Lowpass
Bandpass
Highpass
Notch
Low Shelf
High Shelf
Peak
Comb
Formant
All Pass

Use the familiar filter types to define the main shape. Choose Comb for metallic or repeating-delay resonance, Formant for vowel-like vocal character, and All Pass for phase-based movement. The right type is the one that gives the sound a clear role before modulation begins.

Focus, Spread, and Octave Offset

Focus is the frequency center for the processor, from 20 Hz to 20 kHz. Spread controls how the stages fan outward from that center, from 0.25× to 4×. A Spread of 1× is neutral.

Each stage also has its own Octave Offset, from −10 to +10 octaves. Use it to place one stage precisely, then use Spread to expand or compress the relationship among multiple stages.

At the factory defaults, stages are not pre-spread across the spectrum. They begin stacked at the same frequency until you give them different offsets or change Spread. That makes it easy to begin with a single focused sound rather than inheriting a busy shape.

Static Shape

Resonance and Width

Resonance determines how sharp and pronounced the filter response becomes. On Lowpass, Bandpass, and Highpass stages, higher settings can create a strongly ringing, self-oscillating character rather than a conventional corrective-EQ peak.

The shipped range is intentionally bounded: it gives you intense, musical ringing without turning the stage into an uncontrolled, multi-second tone generator. Push it until the stage becomes a voice in the sound, then back it off if it begins to dominate the music.

For All Pass, this control is labeled Width instead. It changes the breadth of the phase response rather than adding resonant gain.

Gain, Drive, and Stereo Skew

Shelf and Peak stages also provide Gain. Use it for direct tonal emphasis after the filter shape is right.

Drive adds filter-driven saturation when a resonant stage is pushed. It is part of the stage's character, not a separate general-purpose saturator. If you want standalone harmonic coloration without this filter relationship, use The Spark Plug instead.

Stereo Skew offsets a stage's frequency in opposite directions between left and right, from −2 to +2 octaves. At 0, it does nothing. Use small amounts for width and motion; large amounts can create deliberately dramatic stereo contrast.

Comb and Formant

Comb creates a repeating, metallic, or hollow resonance. Its Feedback and Damping controls determine how persistent and bright that character becomes. Positive and negative feedback create different relationships: one reinforces the classic comb effect, while the other creates a more hollow, complementary response.

Formant moves through A, E, I, O, and U vowel-shaped resonances. It is a musical vocal-character filter, not a literal vocal-modeling tool. Use Vowel to choose the shape and Amount to decide how strongly it affects the stage.

Motion

Motion gives a stage internal movement. Every stage can use up to two Motion assignments, M1 and M2, and each assignment can be scoped to that stage or shared globally.

Start with M1. Add M2 only when you can describe what the second movement is contributing.

Motion Source and Target

Choose from seven sources:

Sine
Triangle
Saw Up
Saw Down
Square
Sample & Hold
Smooth Random

Then choose what the source moves:

Frequency
Stereo Skew
Formant Amount
Formant Vowel
Gain

M2 can also modulate Motion 1's Rate or Depth, making it possible to create movement that changes its own pace or intensity over time.

Mod Rate sets the speed. Turn on Sync to lock that rate to the host tempo and choose a rhythmic division instead. Mod Depth determines how far the target moves, and Phase Offset controls how the motion relates across stages.

The large Motion control is the master intensity for all Motion and Sidechain contributions. At 100%, you hear each assignment at its authored depth. Lower it to make the whole system more restrained; raise it to push the movement beyond its original amount. Drift is independent of this control.

A useful first motion patch

Start with one Bandpass or Lowpass stage. Use a Sine source targeting Frequency, set a slow Rate, and bring up Depth gradually. Once that feels musical, add a second stage with a different phase or a different target. This creates complexity from two understandable moves rather than eight unrelated ones.

Sidechain

The Sidechain module lets audio move a selected stage in real time. It can react to the processor's own input or to an external host sidechain.

Internal is the default. It listens to the main input before Drive and filtering.
External listens only to the optional aux input supplied by the host. That audio never enters the audible signal path.

Use Level, Threshold, Attack, and Release to decide how the envelope responds. There is no gain-reduction meter or envelope display, so tune it by ear: listen for when the movement starts, how strongly it responds, and how naturally it returns.

For the selected stage, choose a Target — Frequency, Stereo Skew, Formant Amount, Formant Vowel, or Gain — then set a signed Depth from −100% to +100%.

Positive and negative Depth are equally useful. A positive Frequency depth can open a filter as the source becomes louder. A negative Gain depth can duck a stage away from an external kick. Sidechain, Motion 1, and Motion 2 are added together, so keep their combined range in mind.

Drift

Drift is a global tape- or vinyl-style pitch/time wobble applied after the full filter chain. It is not a filter type and does not belong to any one stage.

Because Drift is after Filter Mix, it can still affect the signal even when Filter Mix is 0%. That makes it useful as a pure movement effect as well as a companion to filtering.

Amount sets the overall depth.
Rate sets the speed.
Flutter adds faster instability.
Stereo moves the channels from linked toward independent behavior.
Tape and Vinyl offer two different motion characters.
Mix blends Drift with the undrifted signal.

Use Drift last. First make the filtered sound convincing; then decide whether instability makes it feel more alive or merely less focused.

Filter Mix, Output, and Safety

Filter Mix blends the pre-filter signal with the complete eight-stage filter chain. At 100%, you hear fully filtered audio. Lower it to retain more of the original source while letting the processed chain supply color and movement.

Output is the final trim, from −24 to +12 dB. There is no hidden gain compensation: stacking resonant or driven stages can build real level. Watch your gain structure and use Output deliberately.

Presets, A/B, Undo, and Bypass

Use presets as starting points, then make the patch your own. The preset strip includes factory presets, user presets, and Save As…. User presets can be renamed or deleted.

A/B holds two full states. Each side is directly selectable, so you can build two complete directions and return to either one instantly. Switching A/B clears the active Undo history by design.

Undo and Redo track normal editing gestures and preset recall. There is no right-click numeric entry in The Focal Point: use drag, mouse wheel, arrow keys, or double-click reset. Hold Shift while dragging for finer adjustment.

Bypass passes audio through unprocessed. Use it for an honest final comparison, especially after adding multiple stages, Drive, and Drift.

Practical Workflows

Build a resonant texture

Enable one Lowpass, Bandpass, or Highpass stage. Set Focus, increase Resonance until it rings with the right amount of personality, then bring in a small amount of Drive if the stage needs more force.

Create an evolving sweep

Set Focus and Spread for the area you want to animate. Add a slow Motion source to Frequency, then use a second stage at a different offset or phase to create counter-movement. Sync only when the movement needs to lock to the song.

Add vocal character

Choose Formant, set a vowel, and use Amount sparingly. Animate Vowel or Formant Amount with Motion when you want the sound to speak, but let the source remain recognizable.

Make the sound react to another track

Choose External Sidechain, route a host aux signal, and use negative Depth to duck a stage from a kick or positive Depth to open a stage on louder hits. The external audio controls the motion only; it is never added to the output.

Add tape or vinyl instability

Leave filtering subtle — or even set Filter Mix to 0% — then enable Drift. Begin with a low Amount and adjust Rate and Flutter until the movement supports the mood rather than pulling focus from the performance.

Updates, Licensing, and Support

The Focal Point is available as AU and VST3 for macOS. The About overlay shows the installed version, provides access to this User Guide and the Mainline Audio site, and lets you enable or disable tooltips.

For current downloads, release notes, and support, visit the product page or support@mainline-audio.com.

Final Perspective

The Focal Point becomes powerful when every stage has a reason to exist. Start with one clear filter decision, make it move only when movement adds meaning, and use the deeper system to support the sound — not to prove how much the processor can do.