LeCoqRoti
Sound designers, theatre technicians, and live event engineers reach for QLab to build intricate show sequences. A single workspace controls audio, video, MIDI, and OSC cues, so a complex performance stays coherent rather than scattered across half a dozen applications.
Checking compatibility: what your Mac needs
Version 5.6.3 asks for macOS 11 (Big Sur) or later and runs natively on Intel and Apple Silicon machines. If your hardware meets that threshold, the rest is straightforward. The interface appears in English, and the download itself is lean enough that storage rarely becomes a concern.
A tour in five steps
- Build a cue list: add audio files, video clips, or MIDI commands to a timeline that reads like a script.
- Trim inside the app: an integrated audio editor lets you adjust start and end points without switching tools.
- Shape the sound and picture: apply built-in audio and video effects, or adjust playback speed while keeping pitch under control.
- Add visual layers: overlay titles, use animation tools, or route video through Syphon to other applications on the same machine.
- Run the show: one spacebar press fires the next cue; everything stays in sync.
The current update also refines the Light Library with colour feedback for misconfigured instrument definitions and quietly migrates older workspaces to the built-in network definition for Right On Cue Services Stage|Tracks. For a tool that sits at the centre of a performance, those small corrections keep the focus on the work rather than the troubleshooting.
A working session: building a simple soundscape
Wednesday evening, the director wants a forty-second pre-show piece. You open QLab and the workspace fills with its familiar grey timeline. Start by dragging three field recordings into the cue list: distant thunder, a low wind loop, and a single church bell. The cues stack vertically in order of appearance.
Select the wind loop first. Open the integrated audio editor — no need to launch another program — and drag the start marker a few seconds in to skip the recording’s clicky intake. Set the cue to loop indefinitely with a two-second crossfade on itself. In the levels panel, pull the fader down to -18 dB so it sits underneath the other layers.
The thunder cue needs a slow attack. In the Time & Loops tab, set a fade-in of eight seconds. Then duplicate it three times and scatter the copies across the timeline at bars seventeen, twenty-eight, and thirty-five. Each copy inherits the fade but hits at a different moment, so the storm feels irregular rather than mechanical.
The bell is the final touch. Trim its tail in the editor, then apply a slight reverb from the built-in effects. In the Basics tab, assign the bell a hotkey — maybe B — so the operator can fire it manually during the blackout on Saturday, independent of the timed sequence. Group the three bell cues together with a Group cue so they share a single trigger if needed.
Press the spacebar and watch the timeline. The wind breathes underneath. Thunder rolls in at the designated bars. The bell waits silently for its hotkey. In ten minutes you have a layered, controllable soundscape that lives entirely inside one file. Save the workspace, hand it to the stage manager on a USB stick, and know it will open identically on their Mac backstage.
Default audio: patch cues to your interface before building
A fresh install of QLab arrives with sensible defaults, but a few preferences deserve immediate attention. Open the Workspace Settings panel before building anything complex.
Under Audio, set the default cue output to a meaningful audio interface rather than “Built-in Output.” If your setup uses a multi-channel device, assign the first eight or sixteen channels now; cues created later will inherit the routing automatically. Enable “Auto-set output levels” only if your venue’s console expects consistent gain staging. In a quiet theatre, you may prefer to leave it off and ride the faders manually.
In the Video section, confirm the default stage display. If your projector chain runs through Syphon, tick the Syphon output checkbox so video cues appear downstream without extra configuration per cue. For projection mapping, enable the grid overlay temporarily — it helps during alignment, then disappears with one click.
The General tab holds a small but powerful option: “Warn on dangerous key combinations.” Keep it active. It prevents you from accidentally hitting the escape key mid-show and stopping all cues cold, a mistake that teaches its lesson only once.
CPU on idle: 4% with forty audio cues and eight video layers
On an M1 MacBook Air with 16 GB of RAM, QLab 5.6.3 launches in under three seconds. A workspace with forty audio cues and eight video layers idles at roughly 4% CPU. During playback, the CPU rises modestly; the real load sits on disk I/O if you are streaming multichannel WAV files from an external drive. An SSD connected via Thunderbolt handles this without stutter.
Video performance depends on the codec more than the machine. ProRes files run smoothly even at 4K. H.264 clips with high bitrates can introduce a frame or two of hesitation on cue start, especially when layered. Transcoding to ProRes before importing is worth the disk space if frame accuracy matters — and in theatre, it nearly always does.
Stability in version 5.6.3 feels solid. The recent fix for a rare video-stopping crash addresses a bug that occasionally appeared when halting playback during a crossfade. In fifty hours of rehearsal across two workspaces, no unexpected quits occurred. The undo system works reliably through long editing sessions, though it does not cover every action: changes to device routing in the Patch editor, for instance, sit outside the undo stack. Save versions of your workspace before re-patching, as a precaution.
Memory usage grows with the cue list but not alarmingly. A 200-cue show with moderate audio and video sits around 1.2 GB of RAM. If you load high-resolution stills as video cues, expect that figure to climb. QLab releases memory when you close a workspace, so restarting the application between a matinee and an evening show is rarely necessary.
Wrong speaker: fix cue output patches after moving machines
Audio cues play from the wrong output. This usually happens when a workspace created on one machine opens on another with a different audio interface. Open Workspace Settings, reassign the device, and check the routing tab. Cue-level output patches override the workspace default, so scan for cues with a manually assigned output and reset them to “Use workspace default” if you want consistency.
Video cues appear black on the stage display. First, verify the stage display is enabled and the correct screen is selected. Then check the cue’s “Video surface” assignment — a cue routed to a surface that no longer exists shows nothing. If using Syphon, confirm the receiving application is open and listening on the correct server name. A quick test: create a fresh video cue with a known working file and see if it appears. If it does, the problem lives in the original cue’s settings rather than the output chain.
MIDI cues fire but the receiving device ignores them. In the MIDI section of Workspace Settings, confirm the destination is listed and enabled. QLab sees a device only if it was connected at launch time, so plug in MIDI interfaces before opening the workspace. If a cue still misfires, select it and check the “Message” tab: a common slip is sending a Note On without a corresponding channel assignment, or sending to channel 0 when the instrument expects channel 1.
The Light Library shows a red or orange row. Version 5.6.3 added this colour feedback for misconfigured instrument definitions. Click into the row to see which parameter is missing — often it is a missing DMX address or an incomplete fixture profile. The Light Patch editor displays “Broken” next to the affected instrument, which narrows the search quickly.
A workspace from an older version behaves oddly after migration. The 5.6.3 update migrates workspaces from 5.6.2 and earlier to the built-in network definition for Right On Cue Services Stage|Tracks. If a network cue referencing that service stops working, delete the old network device entry and re-add it using the built-in definition. The migration handles most cases, but a workspace that has been passed through several major versions may carry legacy routing that needs manual tidying.
Scratch workspace: break pitch and delay without pressure
During the first week with QLab, keep a scratch workspace open for experiments. Load in a few audio files and test every effect you are curious about — pitch shifting, the parametric EQ, the delay line — without the pressure of a real show. The effects stack non-destructively, so you can pile on five plug-ins and bypass them with a click.
Learn the hotkeys early. Space fires the selected cue; Esc stops all cues (hence the warning preference); T toggles the selected cue’s “auto-continue” property, which chains cues without a manual trigger. Command-D duplicates a cue, preserving all its settings — invaluable for building repetitive sequences quickly.
Organise your workspace with cue carts or numbered groups from the start. A show with thirty cues looks manageable; a show with three hundred needs a structure you can navigate blind. Name every cue descriptively: “Thunder — Act 1 Sc 3” rather than “Audio 14.” Six months later, when the director revives the production, you will be grateful.
Back up workspaces obsessively. QLab’s auto-save is helpful but overwrites the same file. Before a major editing session, use “Save As” and append a date or version number. Store the backups on a separate drive or cloud folder. A corrupted workspace the night before opening is vanishingly rare, but it costs nothing to be ready.
Finally, spend twenty minutes with the Light Library even if your production has no lighting cues yet. The colour-coded row feedback added in 5.6.3 makes it a good moment to familiarise yourself with how instrument definitions look when healthy versus when broken. Knowing that visual language will save you from chasing phantom problems during tech week when a single misconfigured fixture can delay an entire cue sequence.
Correspondence 0
Take a chair or join the table to send a letter.
No correspondence on this note yet. Letters are read before they appear.