Sunday, January 22, 2012

What is QLab and What Can it Do For Me?

QLab is audio playback software for the Macintosh. It is from Figure 53 and is designed for use in theater and similar live-playback situations.

It is not a mixer, a signal processor, or a Digital Audio Workstation. It is also not a Cart Machine (although Figure 53 has a digital one of those, too.) Also, there is no Windows or Linux version (although there are other, similar software tools). It is also not the only professional-level software for its specific application -- Sound Cue System for Windows is in a similar price range, and of course there is SFX ...of which I will say no more less my blog get shut down by angry marketing people.

With all that out of the way, what do you want this for? Well -- QLab is easy to understand, plays well with all hardware, plays any file the Mac can play (leveraging QuickTime to do so), takes up very little system overhead....and, oh yeah, the basic version is free. And not cripple-ware or nagware, either.

An aside. There's something about shareware. The shareware philosophy is to build a product good enough that people will want to support you in return. The philosophy is to find problems so they can be fixed; which is directly opposed to the marketing-driven philosophy of mainstream software that says the way to sell the software is to slap lawsuits on anyone who dares mention it doesn't work very well. Oh, and a small annoying and productivity-related thing; notice that shareware is usually better about adhering to GUI standards? Commercial software tends to use unusual functions for the control keys, hide the menu bars, and won't even permit re-sizing of the application window. Shareware tends to keep the look and feel of the underlying GUI and that means it is faster to learn it and smoother to use it in a multi-application work flow.

End rant.

So that's 500 words, and what does QLab actually do?

Think of it like a CD player on steroids. A CD player that can play a dozen tracks at the same time, or one after another, at different volumes, panned to different speakers. Now imagine this massive CD player is set up so well you can command it from a single button once it has been programmed.

I've done shows on analog tape, on CD players, on iPods, on iTunes or Windows Media Player, and all of these are relentlessly linear. They want you to play one sound, then diddle around setting up the next sound. A professional CD player or old school cart machine will play the sound then automatically move to the start of the next track and wait for your command.

QLab does this, but with multiple instances. You can have one sound playing as a background, then play two other sounds in a row, then finally take out the long one. Oh, and you can loop, too.

But that isn't even half the power. QLab treats fades and pauses as just another kind of event. So with the tap of a single button, you can fade down one cue and start up another. Or a dozen different events in a carefully timed cascade.

Let's start with the basics. Visit Figure 53's website and download the free version. Again, it isn't nagware or spyware; it won't ask for internet access, it won't ask for your admin password, it won't require you to fill out and return a form.

When you open it, you are presented with a window. The basic format of QLab is an event list. Events are called "Cues"; each cue is an instruction to QLab to do something. Not all cues need to be operator cues; you can set up some to automatically follow others, and you can stuff several within a group and that group itself becomes a cue. And, yes, it can be recursively nested!

The even type we are most concerned with is a sound. Drag a sound file (basically, ANY sound file...mp3, aiff, wav...) into the QLab window and it will become a Sound Cue. Or insert a Sound Cue in the workspace, and navigate to the pop-up to select a sound file to load.

In Version 2 (the current version) there is a black teardrop that indicates the next event that will be triggered when you hit "Go." This teardrop changes to a green arrowhead when the cue is actually playing. When you fire up QLab for the first time, it will select as audio output whatever your default system output is.

Let's demonstrate some of the power of this software right now. Go into Application Preferences and select Audio. You are looking at the default preferences. Every audio output device your Mac is currently connected to will show up as a potential patch. Let's assume for the moment you have something like the 8-output firewire interfaces I love so much. Pull the yellow wire and patch Patch 1 into the firewire device on the list. Now go back to the main window, select that Sound Cue, and select Levels from the bottom row of tabs. You should see eight possible outputs indicated as round yellow crosspoints, arranged in as many rows as the sound file you are using has channels.

Yes...I have installed and used an 8-channel WAV file and sent each channel out individually to an output on the firewire. But more often, I am playing a simple stereo or mono cue through a selected output.

This gives you tremendous flexibility in placement. Even more so when you realize that QLab can recognize multiple audio devices at one time.

Say I have a simple play with a few bits of music for preshow and scene changes, and one cue that is supposed to sound like it comes out of an on-stage radio. I stick a powered monitor under the table where the prop radio is and run a cable back to the booth and plug it into a cheap USB audio output -- such as an M-Audio Fastrack. I then plug a mini-stereo jack into the headphone output of my laptop and plug the other end of that into the main speaker system.

In QLab, I set the M-Audio as Patch 2. Now most of the sound files I bring in will play by default out of the headphone jack and thus over the main speakers. The one radio cue, I go to the Settings tab in the bottom part of the QLab main screen and select Patch 2 instead of the default Patch 1. This sound, and this sound alone, will go out the Fastrack instead -- and show up in the speaker I put under the prop radio.

Next trick. Still in the Settings tab, click the radio button for Infinite Loop. Just as it says on the box, the cue will now play over and over, back to back (how good the loop sounds depends on your loop points -- setting those is simple, but more than I want to get into on this introductory post!)

So how do you stop the cue from playing? Hit the big "Stop All" button at the top of the workspace? There is a more elegant way than that!

What you want to do is create a Fade Cue. A Fade Cue is one of the many kinds of Cue that does not itself contain content (aka a sound file). It acts upon any Sound Cue...any arbitrary Sound Cue, in fact (it needn't be the cue nearest it). Simplest way to set this up? Select your previous Sound Cue and drag it on top of the Fade Cue. It will be recognized and the Fade Cue will now remember which Sound Cue it acts upon -- even if you rename, re-number, or even re-load the sound files.

The simplest settings are to go to the Levels tab and click the master volume slider. Make sure it is highlighted, and down at the bottom. Also check the "Stop target when done" box right beside that master fader.

Move up to the top of the cue list by mouse click, arrow keys, or the Reset All button at the very top of the workspace. Hit "Go." The sound begins to play, and the "next" pointer will move to the fade cue. Let the sound file loop a couple of times, then hit "Go" again. The sound file that was looping fades softly out.

What I have described above will get you through 90% of all shows, or 90% of the cues in a complicated show. What we've created here is a non-linear playback of multiple sound events that is controlled through a simple linear list; merely by hitting the "Go" button over and over (or the space bar) you can start and fade out multiple simultaneous sound events routed to multiple speaker assignments.

And because of the drag-and-drop access, and the total file-type atheism (if it is a valid sound file, it plays. No need to worry about converting to just the right sound format, or even about putting them in a specific directory), if you need two quick songs or even a dozen straight-forward sound effects, you can set them up for easy one-button playback faster than you can open iTunes.

Oh, and did I mention there's basically no lag?

But of course it doesn't stop there. You can set the start and end points for any sound file within QLab, and of course set individual volumes. You can chain cues to automatically follow one another, with offset start times as well. And of course fade cues do far, far more than fade out; they can bring up, cross-fade, or even change speaker assignments on the fly. Cues can not only have names, they have a comments field that displays for each upcoming cue (on those rare shows when I really have time to clean up, I put the actor's cue line and other notes up there!)

And that is just the beginning. QLab also generates and receives MIDI events, can playback video with the same flexibility it offers for audio...

1 comment:

  1. Please help-- I use the Q Lab free version for school shows and I just made the mistake of upgrading, only to find that I can't use my Mac any more as an output device. WHY isn't the computer itself the default output device? Keep it simple, stupid is my motto. I simply use an aux output patch cord to plug into the sound system, but I need to hear my cue to set them. They won't play at all, so I can't do anything and the show is little over a week away. Can you advise? Thank you! Chagrined Director