LFO Rack — Manual

Contents

LFO Rack sends OSC messages to QLab to automate fader levels, play rates, and spatial audio object parameters — living, waveform-driven movement instead of static settings.

• 1. Launch — double-click to open
• 2. Connect to QLab — Passcode or No Passcode setup
• 3. Add a Lane and Detect Your Target — link a lane to a QLab cue
• 4. Play — start the LFO and stream values to QLab
• 5. Save As — save the show and generate a QLab Startup cue

• Trial & Buying — 14-day trial, then buy a license
• Activating a License — paste a key into Manage Your Licenses…

• What LFO Rack Is — what an LFO is, and why it beats riding a fader by hand
• The LFO Module — Rate, Offset, Shape, Skew+, and the rest of the core controls
• Wave Shapes — all seven shapes, their character, and their bandwidth cost
• The Step Qualifier — turn any smooth shape into a cheaper staircase
• Spatial Unit vs Object Unit — position vs. proximity — two different spatial mechanisms
• Randomize Row — Wobble + Bounce — organic unpredictability with no manual tweaking
• 1-Shot Mode — auto-stop after a set number of cycles or seconds
• Fader Unit — automate a single QLab fader or crosspoint
• Rate Unit — control a cue's playback speed
• Multi Lane — drive a whole row of faders from one waveform
• Object Lane — position a QLab audio object in space
• Spatial Lane — proximity-based fader control along a canvas path
• OSC /live — skip QLab's UI redraw under heavy automation load
• Creating QLab Network Cues from LFO Rack — generate Network cues straight from a lane
• Mark LFO Cues — rename and color-tag QLab cues linked to LFO lanes
• Controlling LFO Rack from QLab Network Cues — start, stop, and enable LFOs from your cue stack
• QLab Hotkey Integration — forward Go, Pause, and Panic keystrokes to QLab
• Safeguards — automatic thinning that protects QLab under heavy load

• Detection Workflow — how Detect buttons link a lane to a QLab cue
• Toolbar — connection fields, transport, and bandwidth indicators
• LFO Module Controls — every LFO module control, field by field
• Wave Shapes — shape parameter and bandwidth per wave shape
• Shape Parameter (Skew+) — what Skew+ does on each shape
• Step Qualifier Controls — toggle and resolution stepper, control by control
• Fader Unit — every Fader lane control, field by field
• Rate Unit — every Rate lane control, field by field
• Multi Unit — every Multi lane control, field by field
• Spatial Unit — every Spatial lane control, field by field
• Object Unit — every Object lane control, field by field
• OSC /live Controls — where the /live toggle appears on each lane type
• Randomize Row — Wobble and Bounce control details
• 1-Shot Mode — Cycles and Secs mode control details
• Reordering — drag handles to reorder lanes and modules
• Creating QLab Network Cues from LFO Rack — full control breakdown for the QLab Cues modal
• Mark LFO Cues — full control breakdown for Mark LFO Cues
• Save, Save As, and Autosave — save, autosave, and backup behavior
• Spatial Lane vs Object Lane — side-by-side comparison table
• Effects Parameters — why Rate Detect can't read AU effect parameters
• Licensing — Credits, Manage Your Licenses, and the license agreement
• Troubleshooting — fixes for common connection and detect problems

• What Is OSC? — OSC in one paragraph, for QLab users who've never sent a message
• Address Anatomy — how to read an OSC address like a file path
• Values and Types — float values and command-only addresses
• The /live Suffix — why /live skips QLab's UI redraw, and when to use it
• LFO Rack Incoming OSC — every address LFO Rack listens for, by category
• QLab → LFO Amplitude/Rate Control — live amplitude and rate control from a QLab cue
• QLab Fader Address Reference — fader/crosspoint address format and indexing
• QLab Rate Address Reference — plain vs. /live rate address behavior
• QLab Object Address Reference — cue-level vs. workspace-level object address families
• Using Network Cues to Drive LFO Rack — parameterize LFO timing entirely from QLab
• Bandwidth Cautions — message budgets and what happens as you approach them

Quickstart

Five steps to live automation. If you know QLab, you'll be running quickly.

1. Launch

Download and install LFO Rack to Applications (see Download on the website) and double-click LFO Rack.app. It runs as a free 14-day trial — see Licensing below.

2. Connect to QLab

Locate your QLab network passcode, or enable No Passcode.

• With a passcode: in QLab, open Settings → Network. Copy the Network Passcode and paste it into LFO Rack's Passcode field in the toolbar.
• Without a passcode: in QLab, open Settings → Network → OSC Access and next to "No Passcode" enable View, Edit, and Control. LFO Rack will connect with no passcode.

The Workspace ID field fills in its numbers on a successful handshake — click it to refresh manually. The Workspace name field turns green and automatically shows the Qlab workspace name indicating the connection is successful.

3. Add a Target Unit and Detect Your Target

Under the LFO Module, click the + Fader button. A new Fader unit appears.

1. In QLab, select the audio cue you want to automate.
2. In the Fader unit, click Fader Detect.
3. Wiggle a fader in QLab until one of the 80+ "link established" messages appear.

LFO Rack captures the OSC address automatically and the Detect button settles on a persistent LINKED label — it stays that way for as long as the lane is linked, not just for a moment after detecting. Click the FADER→ label (arrow) to jump directly to that cue in QLab.

4. Play

Click ▶ on the LFO module. The waveform animates and values stream to QLab in real time.

Three controls to start with:

• Rate — how fast the LFO cycles (Hz by default).
• Shapes — LFO shapes offer many creative possibilities.
• Skew+ — modifies the shapes.

5. Save As

Click Save As in the toolbar and navigate to your QLab folder. LFO Rack saves your configuration as a .lfo_rack file.

Licensing

Every install runs as a full-featured trial before you need a key — here's how the trial works, and how to buy and activate when you're ready.

Trial & Buying

LFO Rack runs as a full-featured 14-day trial from first launch — no key required to start. After the trial ends, the app drops to a Lite tier with one Fader unit remaining available; the rest unlock again once you activate a license. See Licensing Controls for the exact modal fields.

To buy a license: click the LFO Rack logo (or About LFO Rack in the app menu) to open Credits, then click Buy a License — or go straight to lforack.com/buy.

Activating a License

Open LFO Rack → Manage Your Licenses… from the app menu, paste your license key into the Activate with License Key field, and click Activate. License keys are tied to your machine's Hardware ID, shown in the same modal — see Licensing Controls for the full field-by-field breakdown.

Read the terms any time from LFO Rack → Read License Agreement… in the app, or the License Agreement on the website.

Guide

The Quickstart gets you running. This is the rest of the picture — what each control actually does, and why it behaves the way it does.

What LFO Rack Is

An LFO — low-frequency oscillator — draws the same wave over and over, slowly. That's different from a high-frequency oscillator, which vibrates so fast it produces audible sound on its own (your voice, whistle, anything you've ever heard). LFO Rack takes that slow wave, turns it into a steady stream of numbers, and sends those numbers to QLab as OSC messages. Those messages move faders, change play rates, or position audio objects in space. There's no patching and no scripting: you point a Target Unit at a QLab parameter, and press play.

Think of it as a very precise autopilot for your QLab faders. You set the route (the wave shape), the cruising speed (the rate), and how far the controls swing (the depth), then let it fly while you focus on the show. The difference between LFO Rack and riding a fader by hand is the difference between cruise control and holding your foot at a perfectly constant pressure for twenty minutes — the machine doesn't get tired, distracted, or inconsistent.

The LFO Module

The LFO module is the brain. Each one is a self-contained oscillator with its own shape, rate, and depth, and it can drive one or more Target Units — the things it actually controls, covered below. Here's every major control and, more importantly, why it behaves the way it does.

• Rate — how fast the wave repeats, in Hz (cycles per second).
• Offset — shifts the wave position positive or negative relative to the center line.
• Shape selector — picks one of seven wave shapes, covered in the next section.
• Skew+ — a single slider whose name and job change with the active shape: Sine = Skew, Triangle = Angle, Square = Pulse Width, Sawtooth / Rev Saw = Ramp Curve, Rnd Sharp / Rnd Smooth = Span (how far each jump swings from center).
• Canvas preview — a live drawing of the LFO's shape.
• 1-Shot button — switches the LFO from "run forever" to "run for a set number of cycles or seconds, then stop," covered below. 

Wave Shapes

All seven shapes share the same rate, depth, and skew controls; what changes is the character of the motion.

Triangle is the workhorse for movement where up and down should take equal time. Square is your A/B switch. Random Smooth is the cure for the "obviously automated fader" feeling — it adds life without a pattern anyone can lock onto.

Under the shape selector sits Skew+, a secondary slider reused across every shape whose meaning changes with it: on Sine it warps the curve without breaking its smoothness; on Triangle it bows the ramp faster or slower; on Square it's pulse width (how much of the cycle is spent "on"); on Sawtooth and Rev Saw it's ramp curve (straight or bowed); on Rnd Sharp and Rnd Smooth it's Span, the amplitude of each jump. A centered Skew+ gives you the textbook version of the shape; push it off-center to sculpt.

The Step Qualifier

The Step Qualifier is a small toggle that lives on the shape row itself and is available on the five "smooth" shapes: Sine, Triangle, Sawtooth, Rev Saw, and Rnd Smooth. Turn it on for whichever shape you're already using, and that shape starts sending a staircase instead of a continuous curve. Dial the resolution from 2 to 24 steps (default 16) with the arrows next to the stair-step icon.

The reasoning: a Triangle stepped at 24 levels is already smooth enough — it's unlikely anybody is going to hear the volume stepping in motion that fine — while it costs a fraction of the OSC bandwidth a full continuous curve does. Using the step qualifier offers significantly more processing efficiency without giving up the character of the desired movement. A stepped Sine is still recognizably a Sine, just a cheaper one. When a shape's qualifier is on, both the stair-step icon and the shape button itself turn teal, so you can see at a glance which shapes in a busy rack are running lean.

Spatial Unit vs Object Unit

They sound similar and both work with sound in space, but they're two entirely separate mechanisms.

Object is about position. Object moves the yellow dot in QLab's native Object Audio tab — it uses QLab's existing Object architecture to send X/Y coordinates straight to a QLab Audio Object. You aren't moving faders at all; you're telling QLab where the object is, and letting QLab's own spatial renderer figure out the loudspeaker levels.

Spatial, on the other hand, is about proximity. Spatial moves faders directly. It operates on a custom canvas where you place output-channel dots representing speaker positions or QLab channels. A yellow "proximity dot" travels a path you configure; as it moves close to an output dot, that channel's fader rises, and as it moves away, the fader falls. The Spatial Unit automates QLab faders, not QLab's native Object audio engine.

Randomize Row — Wobble + Bounce

Every LFO module has a Randomize row just above the Target Unit launch buttons. This adds two random modulation layers that make LFOs feel organic and unpredictable without any manual tweaking. The Randomize button sets both controls to a random value.

Wobble randomly changes the rate of the LFO from subtle to wild. At low values the LFO rate changes slightly — the period stretches and compresses in an irregular, human-feeling way. At high values the rate wanders aggressively. Wobble never reverses phase; it only speeds up or slows down.

Bounce randomly changes the direction of the LFO. Low values will change direction infrequently, while high values may change direction every cycle or even half cycle.

1-Shot Mode

Enable 1-Shot and the LFO stops being a perpetual-motion machine: it plays for a defined amount, then stops itself. No babysitting, no follow-up cue to kill it.

• Cycles Mode — plays exactly N complete cycles, then stops. Range: half a cycle to 999 cycles.
• Secs Mode — plays for exactly N seconds, then stops. While it runs, the field shows a live countdown ("3.2s left") so you always know what's left on the timer.

Flip between the two modes with the orange/teal pill toggle. Each mode remembers its own value independently, so bouncing back and forth between Cycles and Secs never wipes what you had set.

Target Unit Types
A Target Unit is the interface an LFO module actually drives. LFO Module > Target Unit > Qlab. One LFO module can drive several target units at once, and each target unit carries its own color so you can read a busy rack at a glance.

Fader Unit

Color: orange. Automates a single QLab audio fader or crosspoint.

• OSC Address edit - automatically fills the correct OSC address using the Fader Detect button.
• Detection: Select the Audio cue you want to automate in Qlab, navigate to the "Levels" tab in the Inspector. Click "Fader Detect" in LFO Rack, and then wiggle the level fader or crosspoint until you see see a "Connected!" message in LFO Rack.
• Three different fader tapers: Crossfade, Equal Power, and Linear. The Crossfade taper is designed for crossfades between different audio using -3dB as the cross point, creating smooth fades.
• The Range slider covers the full range of a Qlab slider. Clicking on the solid color between the circle knobs allows movement left and right without changing the relative distance between the handles. 
• Phase offers an adjustable range from 0-360 degrees. Application: you can set up two fader units targeting the "Main" faders, one 180 degrees opposite, to create a quick crossfade effect, or several fader units with incremental phase can create a "follow action" like a wave or chase lights.

Rate Unit

Color: teal. Controls the playback speed (and also pitch) of a QLab cue. You will notice the length of the audio cue in Qlab constantly changing as the rate wobbles over the range of the slider.

• OSC Address edit - automatically fills the correct OSC address using the Rate Detect button.
• Detection: Select the audio cue you want to automate in Qlab, navigate to the "Time & Loops" tab in the Inspector to reveal the "Rate" drag edit. Click "Rate Detect" in LFO Rack, and then wiggle the "Rate" drag edit in Qlab until you see a "Connected!" message in LFO Rack.
• The range defaults to 1x - 2x rate. The max range is 0.10x - 8x. Clicking the solid color between the circle knobs allows movement left and right without changing the relative distance between the handles.
• Phase allows for adjustment of the position of the LFO cycle across 360 degrees.

Multi Unit

Color: green. Controls multiple fader levels or crosspoints on a single track with various shapes and randomizations.

Because multiple parameters are being addressed simultaneously, there's a lot more going on under the hood of the Multi Unit. A single OSC address is unable to adequately show what's going on, so the OSC address is omitted on this unit. 

• Detection: you can either type in the cue number you want to target, or use the "Detect" button and wiggle a fader or crosspoint on the cue you want to target.
• Cue > shows which cue is being targeted. Clicking the > arrow will teleport you to the targeted cue in Qlab.
• Skip allows you to skip any faders or crosspoints you don't want to be part of the Multi's movement. You can type in individual fader numbers (1,2,3), or ranges (1-3).
• # Rows offers you selection of how many rows you want visible inside the unit. Default is 3, and max is 9 (1-fader row and 8-crosspoint rows).
• # Start selects where the fader or crosspoint pattern starts.
• Cycles changes with several selected shapes. In "Rotate," which creates a wave effect across your faders, increasing the cycles creates mini-waves within the main shape.
• Count tells the Multi unit how many faders or crosspoints to move.
• Range is the full range of a Qlab level fader.
• CW/CCW button changes the direction of movement.
• Three different fader tapers: Crossfade, Equal Power, and Linear. The Crossfade taper is designed for crossfades between different audio using -3dB as the cross point, creating smooth fades.
• Each row also has Phase (0-360 degrees), Depth (how far the movement swings), Offset (moves the waveform positive or negative), and Invert (inverts the shape of the Multi movement modes).

• The 6 movement modes:
  • Rotate — phase sweeps sequentially across columns, a stadium wave. Cycles sets how many LFO periods span the column range.
  • Pong — same as Rotate but reverses at the last column and sweeps back.
  • Stripes — at Cycles = 1 every column shares the same value (unison); raise Cycles and the columns split into offset stripes.
  • Seesaw — a fulcrum splits the columns in half; one side rises while the other falls, like a balance scale. The Fulcrum stepper (1–8) sets where the pivot sits.
  • Soundcheck — pushes one fader at a time sequentially. Pulse controls how quickly it steps across the row.
  • Random — each column gets an independent random phase offset. Re-rolls on mode entry.

Object Unit 
Color: Coral. Sends X/Y position straight to QLab's native spatial audio object engine, "The Yellow Dot" — see Spatial Unit vs Object Unit above for the big picture.

• In QLab's Object tab, create an Audio Map and add an Audio Object. This unit controls that object — the yellow dot.
• No Detection function — This one you have to edit manually. QLab doesn't push object-position changes back over OSC, so Detect can't work here. Enter addresses manually: /cue/{N}/object/{name}/position, i.e., "/cue/135/object/A/position" where cue name 135 and object name is A or B as shown in QLab's Object tab.
• The lane shows two canvases, A and B, and allows you to control two "dots" per Object unit. Each canvas lets you draw and preview the path for that object. 

• Shapes: Circle/Line. Circle can also be shaped into an oval using the grey handle in the canvas. Each can be resized using the coral handle.
• CW/CCW controls the direction of travel.
• Rotate rotates the shape.
• Size changes the size of the shape.
• Start position (the green triangle) may be edited directly on the canvas or by using the "Start" drag edit.

Spatial Unit

Color: Lavender. The proximity-based spatial engine — see Spatial Unit vs Object Unit above for the big picture. The Spatial Unit gives you up to 32 "output dots" which the "proximity dot" travels through in circular or linear shapes. The proximity of the dots determines the volume of the output.

• Row 1 — shape and cue: path-shape buttons (Circle, Oval, H-Line, V-Line), a compact → label that jumps QLab to the linked cue, and a Fader Detect button (renamed from plain "Detect" — select the target cue in QLab, click it, wiggle a fader, and LFO Rack links the row the same way a Fader unit does).
• Row 2 — motion and output: curve mode (Xfade / Eq.Pow / Linear), a single Loop/Bounce toggle button, a single CW/CCW toggle button, and the lane's /Live button (see OSC /live below).

• Arc handle (H-Line / V-Line only): a purple ⌒ handle sits at the line's midpoint. Drag it perpendicular to the line to bow the path into a curve; double-click it to snap back to straight.
• Scale View slider: zooms the canvas in and out. Default is 80%.
• Radius Scale: changes all active output radius sizes proportionally. This does not change the values in the actual radius edits under the output fader selection panel
• Output Fader Selection Panel: click the count button to cycle the mapped output-channel count through preset sizes (8 / 16 / 24 / 32), then drag the dots on the canvas to position them.
• FLOAT button: free-drag mode — stops the LFO and lets you move the yellow dot by hand. This is purely a development function, and the float function is deliberately not connected to the LFO, and its movement cannot be recorded or replayed - maybe in v2.0.

OSC /live

QLab supports a /live suffix on many OSC addresses. Appending it "/live" tells QLab to apply the incoming value without redrawing its own UI to show the change, and also without creating an undo point in the undo buffer. The fader stops visibly moving in QLab's UI, but the underlying automation keeps running in the background. For a QLab workspace under heavy automation pressure (a rack full of fast-moving lanes), skipping the redraw and undo offers real efficiency and processing headroom to QLab, since it no longer has to animate a fader cap or slider on screen for every message it receives — it just applies the control values and moves on.

The toggle has two levels that combine with a simple OR: a per-lane toggle, and a rack-wide global toggle in the Options menu (OSC /live (All)). Turning the global toggle on doesn't touch any lane's own stored setting — it just adds its own OR on top of whatever each lane already has. Turn the global toggle back off and every lane reverts to exactly what it had set individually.

Bi-Directional Qlab - LFO Rack Integration

Creating QLab Network Cues from LFO Rack

Every lane header has an [↗ QLab Cues] button. Click it to open the modal, which shows the OSC addresses for that lane and lets you create Network cues directly in QLab — for Enable, Disable, and Toggle (or Start/Stop for LFO-level cues).

Check the boxes for the cues you want to create in Qlab, then click Create in QLab. LFO Rack sends them to the currently connected workspace under your currently selected cue. Each created Network cue is pre-filled with the correct OSC address and named {lfo_id} / {target} — {command} so it's identifiable in your cue stack.

The LFO Cues toolbar button opens the same panel at the LFO-module level, for Start, Stop, Sync, and 1-Shot commands.

Mark LFO Cues

Gives you two ways of visually identifying cues being controlled by LFO Rack: text and color. Marking LFO Cues with text gives you a way of using Qlab's search function to quickly find targeted cues in complicated workspaces. Coloring targeted cues give you a visual indicator of what cues are being controlled by LFO rack. 

QLab menu → Mark LFO Cues… renames and/or color-tags QLab cues based on which cues are currently linked to LFO lanes.

• Which cues are scanned: all lane types that carry a cue number — Fader, Play Rate, Multi, Spatial, and all Object rows. If multiple lanes point to the same cue, it's processed once.
• Tag (rename): appends [LFO], or whatever text you want to add to the beginning of the targeted Qlab cue, to each matched cue's name. Cues already tagged are skipped.
• Set cue color: sends a colorName OSC message to each matched cue. Choose from 8 QLab colors, or the hollow dashed circle to clear the color back to none. The color checkbox enables or disables coloring independently of tagging.

Controlling LFO Rack from QLab Network Cues

You may also create your own network cues inside Qlab to control LFO Rack (it's easier to create network cues from inside LFO Rack, btw.) Every LFO module publishes a set of OSC addresses you can use to control LFO Rack from QLab Network cues — turning LFOs and target units on and off from inside Qlab. Find the addresses in the LFO Cues modal (toolbar button) in every unit; every address has a copy button next to it. Place Network cues inside QLab groups so LFO parameters are controlled from within your cue stack.

Drop these commands into a group cue and the LFO's timing is parameterized entirely from QLab, without ever touching LFO Rack during the show.

The commands you'll reach for most:

Find <id> and lane <name> values in the LFO Cues modal. Rate, depth, shape, and target address are set in the LFO Rack UI — they can't be changed via OSC at runtime.

QLab Hotkey Integration

LFO Rack's window can forward a handful of transport keystrokes straight to QLab, so even if LFO Rack has focus, you can still use Qlab hotkeys: Go, Pause, or Panic without clicking back and forth mid-tech. Toggle this integration in the Options menu (QLab Hotkey Integration) — on by default.

It's automatically disabled while you're typing in any input or text field, and while any modal dialog is open, so it never steals a keystroke you meant for LFO Rack's own controls.

Performance and Bandwidth

Caution: LFO Rack can unintentionally send enough OSC messages to overwhelm QLab's ability to respond to them. Excessive OSC pressure on QLab can cause errors, slowdowns, spinning beachballs, and crashes — use at your own risk. Within reasonable limits LFO Rack works flawlessly.

Safeguards

Built into LFO Rack are several safeguards designed to protect QLab from being flooded with OSC messages. Think of them like a compressor/limiter followed by a bit-reduction stage. The BW indicator in the toolbar is your gauge of OSC output pressure.

BW% (bandwidth) shows the OSC bandwidth budget filling up. When you see red lights, there is some data thinning going on behind the scenes to keep QLab from drowning. 

Automatic resolution thinning. At extreme OSC message volume, the last resort is that the smooth shapes — Sine, Triangle, Sawtooth, Rev Saw, Random Smooth — automatically lose resolution and quantize into discrete steps. The harder you push, the coarser the steps. The canvas preview shows exactly what QLab is receiving, so you can watch a smooth curve turn into a staircase in real time — this is your signal that you're in the danger zone. Square and Random Sharp are mostly unaffected, since they're already stepping shapes and don't consume much bandwidth to begin with. 

Practical limit. In testing, 144 simultaneous targets (4 Multi units × 3 control rows × 12 faders) is QLab's practical ceiling. Past that, QLab's own OSC buffer is the bottleneck no matter how efficiently LFO Rack sends. Test your own rig, but be prepared for spinning wheels and crashes at the extreme end.

Use Network cues to turn LFO's and Target units on and off when not needed. Use 1-shot to automatically turn off LFO's after the movement is no longer needed.

Shape choice for bandwidth-constrained shows. If a show is tight on headroom but you still need controlled movement, reach for the step qualifier on whichever shape you're already using and dial its resolution down to what you actually need. It costs a fraction of the full curve's bandwidth and hands you direct control over how many messages per second you generate — you decide the trade between smoothness and load, instead of leaving it entirely to the automatic thinner.

Reference

Every parameter, every control, every edge case. For the "why," see the Guide.

Detection Workflow

Workflow: select the target cue in QLab → click the lane's Detect button → move the corresponding control in QLab → watch the button settle on LINKED. Once linked, a Detect button reads LINKED permanently — not a temporary reward message — until you unmap the address. All four detect-capable lane types (Fader, Rate, Multi, Spatial) behave identically.

Toolbar

Runs across the top of the window: connection fields, save/module controls, and live bandwidth/OSC/Live indicators.

The Workspace name must match QLab's workspace title bar exactly, including capitalization. Host is the IP of the Mac running QLab — 127.0.0.1 when both apps run on the same machine. Port is set in QLab under Settings → Network (factory default 53000). Passcode is only required if QLab's Network settings have one configured.

The thinning pipeline (triggered as BW% drops) runs four serial layers on every engine tick: a tick gate that skips whole ticks when the rate exceeds budget; shape quantization that snaps Sine, Triangle, Sawtooth, Rev Saw, and Rnd Smooth output to a coarser level set (with hysteresis against boundary jitter); delta suppression that skips resending an unchanged value; and bundle packing that combines a lane's messages into one UDP packet where possible.

Global Live toggle (Options menu → OSC /live (All)): clicking it shows a confirmation popup with a "Don't show again" checkbox (app-prefs only, never saved in the show file). Popup text, verbatim: "Global Live Mode: Changes all LFO units to live mode. Halts all visual movement in QLab: fader levels, rate, object. LFO movement persists in the background. This toggles live mode all-on or all-off." See OSC /live Controls below for full behavior.

LFO Module Controls

The engine ticks internally at 60 Hz — the upper bound for Fader and Play Rate output. Multi and Spatial lanes are capped at 30 Hz to protect QLab; Object lanes are capped lower still, at a constant 15 Hz.

Wave Shapes

Smooth shapes (Sine, Triangle, Sawtooth, Rev Saw, Rnd Smooth) auto-quantize under bandwidth pressure. Square and Rnd Sharp are unaffected — they already produce long constant-value runs that delta-suppression collapses, so they cost far less OSC throughput.

Shape Parameter (Skew+)

A single secondary slider, repurposed per shape:

Centre position is always neutral (symmetric sine, 50% pulse width, straight ramp, mid-span randomness). The value is stored per-shape, so switching shapes and back restores the shaping dialled in for that shape.

Step Qualifier Controls

There is no dedicated "Step" shape in the current build. In its place: a per-shape on/off toggle plus a resolution stepper, occupying the 8th slot in the shape row.

Manual step resolution combines with automatic OSC bandwidth-thinning via min() — whichever is more restrictive wins for that tick. Auto-thin is always a safety net layered on top; it never loosens a manual choice to something coarser than what the user dialled in.

Fader Unit

Orange accent (#e8900a). Drives a single QLab fader (output crosspoint level).

Curve modes — Equal Power: sin taper in dB, midpoint ≈ −6 dB, matches console fader behavior. Linear dB: straight dB ramp, midpoint halfway between min/max dB. Crossfade: sin taper in amplitude (not dB), midpoint −3 dB, designed for two fader lanes 180° out of phase on the same module.

Maximum simultaneous targets: 144 across all fader lanes in the rack — QLab's OSC pipeline ceiling, not an LFO Rack limit. Address pattern: /cue/<cue>/level/<row>/<col>.

Rate Unit

Teal accent (#5ab4c8). Drives a cue's playback rate.

Auto-reset: Play rate lanes reset to 1.0× whenever the LFO stops, the lane is disabled, or the lane has no address.

Plain /rate dual-sends: full 60 Hz to /rate/live for smooth control, ~2 Hz to /rate for visual feedback, keeping the field moving without flooding the undo queue.

Multi Unit

Sage accent (#7aaa6a). Drives a row of QLab faders/crosspoints from one waveform.

Modes: Rotate (sequential sweep, stadium wave) · Pong (Rotate that reverses at the last column) · Stripes (unison at Cycles=1, alternating bands at higher Cycles) · Seesaw (fulcrum splits columns, one side rises as the other falls; Fulcrum range 1–8, default 4) · Soundcheck (pushes one fader at a time) · Random (independent random phase per column).

Max update rate: 30 Hz. Practical ceiling: 6 Multi lanes recommended for reliable live use; 8–9 lanes at full column count can overwhelm QLab. Address format: /cue/<cue>/level/<row>/<col_start+i>, sent per column per enabled row.

Spatial Unit

Purple accent (#BEABE5). Moves a yellow cursor along a canvas path; proximity to placed output dots drives fader level. Controls QLab faders, not audio objects.

Canvas: resized 400×400 → 400×250. The yellow cursor follows the path at 30 Hz. Proximity drives /cue/<cue>/level/0/<col> per active dot: 0 dB at zero distance, −100 dB at or beyond the dot's effective radius (its own radius × the Scale View factor).

Object Unit

Coral accent (#ff6361). Sends 2D position coordinates to a QLab audio object — QLab's own "yellow dot" in the Object tab. Use for spatial-audio objects (Atmos, spatial plugins). This lane controls X/Y position only — there is no Z axis.

Two canvases, A and B (198×198 each), one per row/object, each previewing that row's path.

There is no Detect for Object lanes — QLab does not push object-position changes back via OSC. Addresses must be typed manually. Coordinates run −500.0 to +500.0 on both axes, (0,0) at centre. Object lanes send at a constant 15 Hz cap (obj_divisor = 4, 60 / 4) — slower than Multi and Spatial's 30 Hz.

OSC /live Controls

Two levels combine with a simple OR: a per-lane toggle and a rack-wide global toggle (Options menu → OSC /live (All)). Either one being on makes that lane's sends live; per-lane buttons are never force-checked or disabled by the global toggle.

Colors (one unified scheme across every /live surface — badges, buttons, address-field borders, Multi row-card borders): inactive #A28863 text / #B01511 border; active #BD1613 for both text and border.

Every lane type also shows a right-aligned /live badge on its collapsed row, editable without expanding the card.

The global toggle's confirmation popup text, verbatim: "Global Live Mode: Changes all LFO units to live mode. Halts all visual movement in QLab: fader levels, rate, object. LFO movement persists in the background. This toggles live mode all-on or all-off." It has a "Don't show again" checkbox saved to app prefs, not the show file. When the global toggle is on, a small red LIVE tag appears in the toolbar's OSC-meter cell.

Randomize Row

Wobble is a bounded random walk on phase increment, clamped so the LFO never reverses or stalls, only speeds up or slows down. Bounce fires a periodic direction reversal via a countdown timer (4–8 cycles between flips at low Bounce, 0.25–1.5 cycles at high Bounce), redrawn each time it fires. Both reset on LFO restart. Independent and additive with each other.

1-Shot Mode

Cycles mode: stops after exactly N complete cycles. Valid values: 0.5, and integers 1–999. 0.5 plays exactly a half-cycle (rise to peak, stop) for a clean one-way transition.

Secs mode: stops after exactly N seconds of runtime, accurate to within one 60 Hz tick (≈17 ms), counted from the moment ▶ is pressed. Both modes remember their values independently.

Reordering

Drag the ⠿⠿ handle in any lane header to reorder lanes within a module. Drag the ⠿⠿ handle in any module header to reorder modules in the rack. Changes persist immediately to session state and are included in Save As.

Creating QLab Network Cues from LFO Rack

The modal is a two-tab layout: Controls (active by default on open) and Instructions. The Controls tab lists this LFO's Start/Stop/Sync rows, then an "All LFOs" section with workspace-wide Start All / Stop All rows (each still has its own per-row inclusion checkbox, same as every other row — the difference is scope: they target every LFO module, not just this one), then 1-Shot control rows. The Create in QLab button lives at the bottom of the Controls tab.

Each created cue arrives pre-filled: OSC address in the message body, cue name {lfo_id} / {target} — {command}. Requires an active QLab connection. With no workspace connected, a toast shows "Failed — is QLab connected?". With no boxes checked, the button does nothing.

Mark LFO Cues

QLab menu → Mark LFO Cues… — scans all linked lanes for cue numbers and sends rename and/or color commands to those cues in QLab.

Lanes scanned: Fader (from OSC address), Rate (from OSC address), Multi (Cue field), Spatial (Cue field), Object (all row addresses). Duplicate cue references are de-duplicated and processed once.

Save, Save As, and Autosave

Spatial Lane vs Object Lane

Effects Parameters

QLab does not expose audio Unit effect parameters via OSC feedback. Rate Detect cannot detect AU changes — QLab doesn't push them back, so there is nothing for Detect to read. Direct OSC sends to AU parameters may work for some parameters if you know the address (enter it manually in a Fader lane); not officially supported. This is a QLab limitation, not an LFO Rack one.

Licensing Controls

Concept and workflow: see Trial & Buying and Activating a License in the Licensing section above.

Troubleshooting

1. LFO is playing but QLab fader isn't moving

1. Confirm the workspace name matches exactly (case-sensitive).
2. Check the out indicator flashes when the LFO is playing.
3. Verify the OSC address by sending it manually from a QLab Network Cue.
4. In QLab, confirm OSC receive is enabled on port 53000 (Settings → Network).
5. Confirm the QLab access level.

2. Workspace name won't turn green

1. Double-check the workspace name against QLab's title bar — case-sensitive.
2. Confirm the access level in QLab Settings → Network: enter the Passcode, or enable View/Control/Edit in OSC Access.
3. If QLab is on a different machine, confirm the Host IP and that both machines share a network.

3. Fader Detect captures the wrong cue

1. Make sure the target cue is selected (highlighted blue) in QLab before clicking Fader Detect.
2. Moving the fader of an unselected cue won't trigger detection.
3. After selecting, click Fader Detect again before moving the fader.

4. Rate lane is not affecting playback speed

1. Check the cue is currently playing — /rate/live only controls active cues.
2. If stopped, the stored rate (plain /rate) updates, but live speed control takes effect only once the cue starts.
3. Confirm the lane's address is correct via the RATE→ button.

5. BW% drops quickly with few LFOs active

1. Check active Multi lane count — each can send up to 12 addresses × 30 Hz.
2. Reduce Multi lane count or col count.
3. Turn on the step qualifier on smooth shapes to cut message volume.
4. Raise the Max OSC budget in the toolbar if your system can handle more throughput.

6. 1-Shot stops too soon (Secs mode)

1. Confirm the mode pill is teal (Secs), not orange (Cycles).
2. Check the value in the input field.
3. Secs mode counts from the moment ▶ is pressed, not from when the LFO was last configured.

7. macOS blocks LFO Rack from opening

1. LFO Rack is signed and notarized, so a plain double-click should work. If macOS still blocks it (e.g. a damaged download), right-click the app icon in Finder and choose Open.
2. Click Open in the confirmation dialog.
3. If that still fails, re-download LFO Rack — the download may be incomplete or corrupted.

8. Object position not responding to OSC

1. Confirm the QLab access level is Edit (object position requires Edit, not just Control).
2. Verify the object name matches exactly (case-sensitive) in QLab's Object tab.
3. Confirm you are using the /live variant of the address for real-time control.

OSC Reference

You don't need to know OSC to use LFO Rack — Detect buttons and copy-paste workflows configure it for you. But the moment you want to drive LFO Rack from a QLab Network Cue, target a spatial object by hand, or figure out why a message isn't landing, a little protocol knowledge goes a long way. This section assumes you know QLab cold and have simply never typed an OSC message yourself.

What Is OSC?

OSC — Open Sound Control — is a networking protocol for audio and media gear. Think of it as MIDI's more flexible, network-native cousin. Where MIDI speaks in fixed channel numbers and note values, OSC speaks in addresses that read like file paths, e.g. /cue/Scene_1/level/0/1. The value you're sending travels alongside the address in the same message.

OSC rides over your local network as UDP — fast, essentially instantaneous, and fire-and-forget: there's no delivery receipt. (That "no receipt" part matters — it's why the /live suffix below has trade-offs to weigh.)

The practical payoff: one app on your network can automate many parameters on a QLab machine, addressing each by name — no MIDI cables, no channel-count ceiling, no patch bay. Just names and numbers over the wire.

Address Anatomy

Every OSC message starts with an address. Reading one is exactly like reading a folder path — broad on the left, specific on the right.

/cue/Scene_1/level/0/1 — read as: the crosspoint level (fader) connecting output 0 to input 1, inside the cue named "Scene_1."

/lfo/lfo1/start — read as: the start command for LFO module "lfo1" inside LFO Rack.

The pattern, every time: starts with /, segments separated by /, reads left-to-right from broad to specific, last segment is usually the parameter or command name. Learn to scan an address this way and most of OSC stops being mysterious.

Values and Types

OSC messages carry a typed value alongside the address, so the receiver knows how to interpret it. LFO Rack sends two kinds:

• float — a decimal number such as 0.75, -327.4, or 1.0. The workhorse: fader levels, positions, rates.
• nothing — just the address, no value. This is how commands like start and stop work — the address is the instruction.

You never have to declare a type by hand; LFO Rack tags every outgoing message correctly. When you write a Network Cue to drive LFO Rack, QLab handles the typing for you too — you just type the number.

The /live Suffix

QLab supports a /live suffix on many of its own OSC addresses. Appending it tells QLab to apply the incoming value headless — update the parameter without redrawing its own UI to show the change. That matters because QLab's redraw isn't free: animating a fader cap or a slider on screen for every single incoming message costs QLab real processing time. Skip the redraw and QLab just applies the number and moves on.

Reach for it when the automation load is heavy — many lanes running simultaneously, all streaming updates at once. A handful of fader lanes rarely needs it; a rack full of fast Multi and Spatial lanes usually does. If QLab's UI feels laggy or a busy show is pushing your BW% chip into yellow or orange, /live is the first thing to try before you start cutting lanes.

LFO Rack exposes it as two toggles that combine with a simple OR: a per-lane toggle (the /L badge or /Live button on each lane), and a global toggle in the Options menu (OSC /live (All)) that ORs on top of every lane's own setting. Flip the global toggle off again and each lane reverts to exactly what it had set individually — nothing is lost. Full control-by-control detail on which addresses accept /live lives in the Reference section.

LFO Rack Incoming OSC

LFO Rack listens on UDP port 9000. Every incoming address follows the shape /lfo/<id>/..., where <id> is the OSC ID of the LFO module you want to control.

To find a module's ID and every exact address it responds to: click ↗ LFO Cues in the toolbar. The modal lists each one with a copy button right next to it — paste straight into a QLab Network Cue, no typing required.

Playback commands

Lane control commands

Lane names are the single-word OSC identifiers assigned to each lane, shown in the lane header and in the LFO Cues modal.

1-Shot commands

Global commands (no <id> — these hit every module at once)

QLab → LFO Amplitude/Rate Control

Two more incoming addresses exist for real-time control from QLab, beyond what the commands above cover:

Amplitude is a live multiplier, not a one-shot value — it scales every tick's output for as long as it's set, the same way a fader on a mixer scales a signal. Ride it from a QLab Network Cue inside a fade group: drive it from 1.0 to 0.0 and the LFO winds down in place, phase-coherent, instead of snapping to zero the way stopping the LFO outright would. Bring it back to 1.0 and the automation resumes exactly where it left off.

Rate works the same way the Rate slider does — it's the identical underlying value, so a message here also moves the visible slider in the LFO module in real time. It just gives QLab a way to reach that slider without you touching the app.

Neither has a dedicated field anywhere in the LFO Rack UI — these are raw-OSC-only, typed by hand into a Network Cue. One behavioral note worth knowing before you rely on amplitude for a fade: at amplitude = 0, the wave signal is scaled to zero before it's mapped onto the lane's configured range, so the fader parks at the exact midpoint of that range — not wherever the Offset knob has it centered. Offset gets scaled to zero right along with everything else.

QLab Fader Address Reference

Address format:

Output and input are zero-indexed channel numbers. Example: /cue/Scene_1/level/0/1 controls the crosspoint at output 0, input 1 of the cue named "Scene_1."

Strong recommendation: use Fader Detect rather than building these by hand. QLab's channel numbering isn't always obvious from the UI — it varies by cue type and by the routing matrix — and Detect reads the exact indices straight from QLab.

Two convenient details: cue names with spaces work fine (QLab handles them), and cue numbers (plain integers) work anywhere a name does.

QLab Rate Address Reference

The full trade-off lives in The /live Suffix above. The short version:

• Plain /cue/N/rate → LFO Rack dual-sends automatically (60 Hz to /live, 2 Hz to the UI). This is the default, and what you want most of the time.
• /cue/N/rate/live → zero undo entries, no UI update, affects only currently playing cues.

One gotcha worth repeating: a /live rate address only affects cues that are playing at the moment the message arrives. The cue's stored rate updates regardless of /live — it's the live playback speed that requires the cue to be running.

QLab Object Address Reference

Object addresses target spatial audio objects — the named "yellow dot" point sources in a QLab audio map. They're not cues, files, or channels; they're addressable spatial points you name in QLab. There is no Detect for objects (QLab won't broadcast their positions back), so these are addresses you'll type by hand.

There are two address families:

Cue-level — use this for real-time LFO control:

Affects the object inside a specific running cue. Does not persist beyond that cue.

Workspace-level — global, persists in the project:

Affects the map definition globally. Use this for permanent positions, not continuous LFO motion — you don't want that baked into the saved project.

Position

Coordinate range: ±500 on both axes. Access level required: Edit in QLab — without it, position messages are silently rejected, a common "why isn't it moving?" culprit.

Spread

Range: 0 to 2× the largest map dimension. Cue-level spread is not confirmed in the QLab OSC dictionary — use workspace-level spread for reliability.

Wildcards

QLab evaluates wildcard patterns in OSC addresses server-side, on its own end — a single message can address several objects at once.

Type wildcards directly into an Object lane's address field — they pass through to QLab unchanged. Smart move before a show: test the pattern on a lane with an editable address field (Fader, Rate, or Object) first, to confirm it resolves to the objects you expect before you trust it live.

Using Network Cues to Drive LFO Rack

Configure rate, depth, shape, and target address in the LFO Rack UI before the show. Then use Network Cues to automate timing:

Setting this up in QLab:

• Point each Network Cue's destination at LFO Rack's host and port 9000.
• Set the message type to OSC.
• Paste the address from the LFO Cues modal (copy buttons are right there) and add the argument.
• Fire cues 1–3 in sequence, or bundle them in a simultaneous group.

The big win: you parameterize LFO behavior per scene from inside your QLab workspace, without ever touching the LFO Rack window during the show. The rack becomes just another instrument your cue list drives.

Bandwidth Cautions

OSC is fast, but QLab has a ceiling. Picture QLab's OSC input as a doorway: any single message walks through easily, but a whole crowd rushing it at once jams the opening — and unlike a real doorway, QLab may freeze rather than merely slow down. Respecting the limits keeps your show solid.

Practical limits:

• Fixed budget: 600 messages/second. This is a built-in ceiling, not a toolbar setting — there's no user control for it.
• Multi lanes: up to 12 addresses × 30 Hz = up to 360 msg/s per lane. Keep to 6 or fewer for reliable live use. Past roughly 8–9 Multi lanes at 12 columns, QLab can freeze.
• Fader lanes: 144 simultaneous targets is QLab's practical ceiling.

What happens as you approach the limit: LFO Rack watches rising load through its BW% chip and automatically begins thinning — sending fewer messages, spaced further apart. Smooth shapes (Sine, Triangle, Sawtooth, Rev Saw, Rnd Smooth) visibly quantize into steps. You'll see this in the canvas preview before you ever hear a problem. Square and Rnd Sharp are unaffected, because they were already step-like.

Recommended for bandwidth-tight shows: turn on the step qualifier for whichever shape you're already using and dial its resolution down to what you actually need. It costs a fraction of a full continuous curve's bandwidth and gives you exact control over how many updates per second you generate, instead of leaving the trade-off entirely to the automatic thinner.

Don't push past what your system has tested clean. The real ceiling shifts with Mac performance, QLab's cue count, and network conditions — treat these numbers as a safe default, not a hard guarantee.