How Do I Apply Qlab to Rafter in Theater?

Someone landed here using the above as a search term. I am intrigued. I wonder what it was they were trying to find, and if anything I wrote was any help at all. (That particular search seems to turn up mostly references to James Bond computer games...!)

What would Qlab do with a rafter? Or would it be ON a rafter? Since it is software, it can't "be" anywhere by itself, but you could certainly stick it on a Mac Mini and stick that in the rafters. I've seen workplaces with Mac Minis tucked behind display screens running video loops.

Qlab isn't just sound playback software. It will also play back videos. And it will also generate MIDI events. I know, I know; MIDI is old school. OSC gives you more detailed control and is the current choice among experimental musicians.

But MIDI is out there. There are control surfaces (such as, the Korg nano series -- I have seen video of a Korg nano-slider being used to control remote cameras in real time) Or the Behringer BCF2000, a motorized 8-fader control surface, that are already capable of communicating via MIDI.

There are lighting consoles (and some automated fixtures) that already speak MIDI. On a dance show a little while back we ran the entire show from Qlab, and while each music track was playing multiple Qlab auto-follow cues spat out MIDI Show Control commands to the lighting console, calling up non-sequential access lighting looks.

And when you include MIDI Show Control, there are motor controllers that respond to MIDI. So Qlab could actually do something to a rafter.




On the flip side of the interaction, I prefer using MIDI surfaces to control Qlab, as MIDI "Go" and "Stop" commands will execute regardless of where the cursor is or if Qlab is even focused. A Korg nano-key has been good for that; I double-stick tape it to the top of the sound board and mark off the "Go" and "rewind" keys with board tape and Sharpie.

My nanokey, looking a little battered.

I hasten to add that Sound Cue Systems and SFX also have these abilities, plus there are some other tricky ways you can get the same kinds of interactions with other software or even hardware options (I've done more than one show with an old Roland "Doctor Sampler.")

It is when you geek out a little, though, that things really open up. MIDI is, as a language, quite simple and robust, and so is the physical layer. As one example of designing a new physical layer, a single resistor is all you need to get an Arduino micro-controller to spit out not-quite-standard, but still quite readable MIDI. I have yet to find a device that my Arduinos have been unable to talk to.

A couple more components (in the schematic I've been using, a diode, an opto-isolator, and a couple of resistors) allows the Arduino to receive MIDI via its serial port (I haven't yet tried this with Soft Serial but I have good reason to believe it may work.) It also may be possible for an Arduino to emulate USB well enough to fool a computer into accepting a MIDI signal via USB. There are better solutions, however, to this particular physical connection!

Here's the simple MIDI-in schematic:

From carcat's Instructable

Using simple software like Processing, you can write little translators that will act as go-betweens for serial devices, HID (like mice and keyboards), and internal and external MIDI ports. The simplest form of this is to take a serial data input (such as the Arduino, which shows up as a COM port), and translate the serial stream into internal bus MIDI which Qlab will then read and act upon.

Or reverse the sequence; have Qlab's output translated into serial or USB output which then drives a relay board.

I prefer using MIDI for the intermediary myself because I like the self-documenting aspect of that physical layer. You know which devices will respond because they are physically connected with MIDI cables, and the correspondences can all be made linear and logical; instead of having the first relay be "fred" and the second relay be "ethel" and you've forgotten what name the third relay answers to, you know you always start with MIDI note number 1, so all you have to do is count up.



So far, practically, all I have done is used MIDI and micros to trigger sound effects from Qlab. Although I have connected both Qlab and SCS with a lighting console, Qlab has almost always been the slave in the chain; the lighting console has sent the MIDI command that keeps Qlab's sound events timing-locked to the console's lighting events.

I finally have a MIDI-controlled servo lying around that I could drop into a show that needed it. Up until now, the only gadget I've had in that ready-to-go form has been my remote buttons. And they are overdue for Version 3.0; for longer range RF, for user feedback, etc.

The MIDI-controlled projector douser -- or, rather, a MIDI-controlled servo.

The douser has a MIDI in port, a bicolor status LED, a DC power jack (for a wall-wart, sigh), and a 1/4" jack for controlling it with a simple on/off switch.

This is the current version of my MIDI-in button. The terminal strip is for inputs, a MIDI-out port is on one side, and USB programming/power port on the bottom.

For the picture, it was being powered from my Minty Boost; a 5V USB power supply in an Altoids tin. (Kit from Lady Ada.)

Unfortunately, even though the current box can be powered from, and programmed over, USB, it can't send MIDI through USB. So added to the tangle of wires is an M-Audio MIDI-to-USB interface.





My current tinker project is a dedicated Qlab control surface. I think I've finally found the best chip to use; an Atmega32u4 on a breakout board sold by Adafruit. The chip is one of ATmel's USB-capable AVR chips; just attach the connector and it is a class-compliant USB device out of the box. Using the LUFA library I should be able to make a USB-powered MIDI controller surface. I have a small flat project box purchased for the project, with some big clicky buttons on it.

Of course, since the linking of MIDI events to Qlab operations happens in the Qlab preferences, if the device is set to raw MIDI it could be used for anything...even as a very short keyboard.

Alternatively, I might program it to spit out MSC instead, which is hardwired to Qlab's playback commands.

The biggest problem I'm having with the device is feature creep. There's plenty of space to include some jacks to drive a remote button or two, for instance. And I've used this enough times that I should probably make it available.

My latest version of the physical layout is to make the jacks 1/4"TRS. The upside is a smaller footprint on the back of the device, meaning you can fit them in easier. They are also simpler to mount -- and a lot less annoying than the dangly XLR tails I have on my current version of the box.

The downside is needing lots of TRS to XLR adaptors to run the signal from the remote buttons or sensors through the existing theater wiring. In any case, having three conductors available means I can add status lights to the remote units; they would light up when they "saw" the base station, and with a little more cleverness might even change color when the base station reported it had received a go command (this would tie up three digital I/O pins, though.)

It is also tempting to try to shove an Xbee module, or a 915kHz radio, to permit use of wireless remotes.

That is also something I need to find time for. My current wireless has mostly been useful for checking monitor speaker, although I did use it for a gunshot effect in one play.

The RF-MIDI remote shield, currently without a spare Arduino to host it.

My dream is to make a small robust transmitter that is as plug-and-play as my current remote wired button. The likely form factor is not a keychain remote, but more like a cigarette-pack case with internal battery and a jack for the sensor. The sensor options would include a Hall-effect switch or an opto-interrupter that could be non-destructively retro-fitted to a prop gun in a couple of minutes, allowing that prop to then remotely trigger sound effects.

(As well as lighting effects, physical effects, pyrotechnics; once the signal is in the digital domain not even the sky is the limit.)

The Big Prop

I'd forgotten one of the reasons I migrated here: that was to be able to post explanatory pictures.

Well, to inaugurate the audio-visual aspect of this presentation, a picture of the prop that has been taking all my spare time for almost two months.

This is the Fury Gun (well, actually, this is a picture from a couple days ago, prior to the final touch-up and details...like the sights!) A 1930's Pulp Adventure 45mm double-barreled break-open grenade launcher.

It is a practical prop; largely metal, using some actual gun parts (like the pistol grip and the butt stock). Pressure on the forend unlatches the barrels which pivot open for re-loading. The pistol grip and butt stock can be removed for cleaning or storage. And the entire barrel and breech assembly pushes back on a buffer spring (which was a LOT of work for what turned out to be not that interesting an effect!)

Materials run the gamut; from actual gun parts to 3d printing to steel barrels and 1/8" brass tube making up the receiver and 1" black pipe adding strength to the forend, to details of Apoxie Sculpt and styrene.

The foam plastic grenade is a stand-in. The client who I made it for is making up some rounds out of plastic. I might do a couple myself...once I recover my strength!

A Few Simple Rules for Wireless

1) Location, Location, Location. Site your receivers. If you can get them close to the stage, with a good line of sight, do it. In the wings, or in the orchestra pit on risers so they at least foot level is great. Audio snakes are cheaper than antenna boosters. But if you can afford antenna distributors, do those to...if nothing else, they make it a lot simpler to set up and strike.

2) Location, Location, Location. The best sound is from the forehead, just under the hairline. If the actor is wearing a wig cap, run the cord under it. If they have thick hair, bobby-pin the cord to their hair; near the back of the head, and near the top of the head so it doesn't flop down over to one side. Bobby pin or tape at the forehead. Don't be tempted to pull it down until it looks like an Indian Caste Mark -- it will do what it needs to do from hidden within the hairline.

The second best sound is along the cheekbone. The temptation again is to run the mic directly towards the mouth and tape it on the soft part of the cheek. Don't. You get nasty resonance you will have to notch out. Keep it up on the cheek bone and use the natural planes of the face.

For a really, really weak voice, invest in something like a Countryman E6 and use the boom to place it just outside the corner of the mouth.

3) Location, Location, Location. The most comfortable spot for most actors with dance or heavy physical movement is the small of the back. Use or create a microphone pouch with a wide (1" or better) elastic belt. Stitch a pouch that holds the transmitter and velcros closed. Have the actor wear the belt high and snug, just below the rib line. But be guided by the actor in this; they know better than you what their role demands and what will keep them comfortable on stage.

4) Location, Location, Location. Put the sound board where you hear what the audience hears. Try not to be under a balcony (because there are strange room nodes under most of those), try to be in the area covered by the main speakers. If you have any reason to believe the coverage is uneven, get up from the board several times during the tech process and take a listen from different parts of the house.

It is just barely possible to mix on monitors. My preference, the few times I've been forced to it, is to set up a binaural pair in the house and mix wearing earphones. Simply monitoring what you are sending to the speakers does nothing; you need to hear what the sound in the building sounds like (well, unless you are a million-dollar rock show...but that's a whole different game). At the moderate levels of theatrical reinforcement some portion of the sound will be direct acoustic -- if nothing else, the stomping feet of the dancers and leakage from the orchestra pit -- and you have to blend your input with that.

Paranoia

The Computer is Your Friend. The Computer will help you become happy...


No, no, wait. Not that Paranoia. This post is about a useful attitude for people working in technical theater.

There are places and times where mistakes are recoverable. Early in the design process, early in the build, you can stop, toss out the failed experiment, and try again. But there are also -- in time as you get closer to opening night, and in safety as you get closer to the actor or audience -- that error or accident is going to hurt a production, or worse yet, a human being.

An expression among certain engineers is "Physics never sleeps." It is a rephrasing of the better-known "Murphy never sleeps." The rephrasing is to point up that humans can make lots of mistakes, can forget to account for a shear load or incorrectly calculate a thermal expansion, but the universe is never caught napping. It will always act, inexorably, whenever you give it an opening.

Much of theater engineering is not based on any rigorous analysis or calculation. Much of it is not applied with any real understanding of the underlying physics. What most theater technology is, is a set of robust empirical solutions. The basic 2x4 framed platform, for instance, works because it is overbuilt. The excessive strength of the construction usually makes up for eccentric loading and other misuse of the structure.

This means, however, there is no analytical tradition in theater. There is no equivalent to what they teach engineers, or the school of Defensive Driving; no established school of theatrical thought that makes it its business to check the work before the Universe checks it. There are established procedures that check to see if something is functioning (pre-show checks, for instance) but none that test if something is on the verge of failure.

That's why I like to be the professional paranoid on a build.



It is easy to characterize always expecting the worst as a negative. This is why I try to restrict what I actually communicate to two categories; those potential failures that are easy to fix, and those potential failures that are likely to cause human injury (or expensive damage).

The first assumption you have to get rid of is that there is such a thing as foolproof, or failproof. No matter how sturdy the hardware, base your analysis upon the assumption that it will break anyhow. Then ask what happens. It is this looking forward, the "what happens next?" that is most not done. The few times that people may look at a piece of hardware or a piece of a set or a bit of wiring with suspicion, they almost always look at it in static terms. Is it holding up? Does it look strong enough to keep holding up?

What you have to do is think through an unfolding accident. Visualize where the stresses go, visualize the worst-case. WHICH WAY does the platform fall? WHERE are the loads when the first turnbuckle fails? WHICH LEAD is the "hot" if that other conductor gets severed?

Inevitably, you will discover situations in which two high-probability conditions, which taken in isolation cause low-impact accidents, combine to make a severe accident. IF the lightweight hardware fails AND an actor is standing on the bad corner at the same time, then...



Being paranoid is also checking, checking, checking. Don't rely on memory. Don't rely on co-workers. Don't expect that since the switch was "off," it will remain "off" while you work on the exposed conductors.

More than anything else, assume stupidity. Don't flip a switch, put a piece of tape on it and write "Do not use." Because as sure as apples fall from trees, someone is going to decide it doesn't apply to them, it is an old piece of tape and the thing was fixed years ago, or they are smarter than the person who put the tape down and THEY can make the switch work by flipping it to the "on" position.

Leaving you screaming and holding on to a bare wire on the other end. Or starting a fire as a fog machine with no water in the drum is energized and left heating up in an unobserved corner.

Get into the habit of physically denying access. Lock out breakers. Remove buttons. Unplug equipment. Don't trust to tape and labels. And never, ever trust that no-one will mess with it because no-one is supposed to go into the booth anyhow.



Plan to be late. Plan for something to come up; the set ships late, the choreographer changes his mind, there's a substitution in the cast, whatever. Don't ever start a plan with "We'll pull an all-nighter on Thursday and be ready to open Friday." Front-load. Build all you can early, so when things go wrong there are hours left in the day you can add!


Use all of your senses. Be an actor...move through the set handling things to discover if there are stumble hazards or sharp edges. Listen for sound wood, taut cable, loose hardware. Smell for overheated or burning things.



And this whole post is terribly rambling. I'll blame the long shifts I've been on this week. But I'll try to conclude with a couple of specifics.

Always assume the mic is live.

Never put your head in front of a monitor if you aren't in control of the situation. One careless muso, one blare of feedback, and you will be wearing a hearing aid for the rest of your career.

When in doubt, use dynamics. When a cable with Phantom Power goes bad, it makes a horrible pop that can destroy speakers. Hand the clumsy singer a dynamic mic instead.

Never leave a radio mic up when you aren't at the board. You really, really don't want a "Police Academy" moment.

Never allow any liquid to get above the level of the sound board. If you MUST drink coffee in the booth, sit way back and lift it as low as possible so WHEN you spill it (which you will!) the splash doesn't reach the expensive electronics.

Always stick a spare cable into your under-stage run. Always leave a free channel on the snake. Always leave a length of XLR in the pit until you are SURE all the musicians have finished re-arranging themselves.

Dress cable from the dead end. You will almost never have to move the wall but you will frequently have to move the mic so you want the slack THERE, not forty feet away where it does you no good. Don't tape it until it has been tested (if at all possible -- in high-travel areas, safety trumps efficiency).

Test the mics constantly. Use your PFL when the band returns after intermission, while there is still time to remind them to plug back in or put the mic back where it belongs.

A Change of Focus

I've let this blog slide for the past month. Although I designed one show, mixed another, and consulted for three more (one which opens next week), I've been downplaying sound and sound design. My focus for the last several weeks has actually been, of all things, on a prop.

I used to do props. I started on the carpentry side of the house. Designed scenery in High School, went on to do a handful of small shows outside (what I call "Back of the Pick-up Truck" set designs...your "shop" is the tools you can carry with you, you purchase all the materials and rent all the props yourself, and often as not you have a table saw set up in the back of your pickup truck.)

Even after I went over to the Dark Side...I mean, to the Electrics side of the house (aka lighting and sound), I tinkered with a proplike project or two using some of those same old theatrical carpentry skills.

Within the last few years I did a quick-and-dirty "Steampunk" re-dress of a flashlight (I was working onstage for a Steampunk-themed production of "Tales of Hoffman.") I also built an amp for a vintage headset and stuck it in a cool box with some 40's trimmings.

And now I'm building a prop gun for a friend.




I have a very Commander Data way of working. I don't know if you remember Star Trek "The Next Generation" but the gag was, when Data got a bug in his positronic circuits about something, he'd start by reading up obsessively. The gag usually came out in the form, "I have read four thousand, five hundred and sixty-eight books about humor, and the complete biography of Joan Rivers. I have also memorized twelve million and ninety-one knock-knock jokes."

I have been archive-trawling through Star Wars and other movie prop replica forums, reading up at Micro-Lathe, at Instructables, reading up on aluminum casting and CNC routing and how to operate a Bridgeport Mill and leatherwork and casting and sculpting...

I purchased a whole handful of cheap tools, gambling that my long shop experience would help me both avoid the really bad deals and work around the bad spots in the tools I did get (so far, the major disappointment has been the cheap Harbor Freight jigsaw, which is, well, quite useless.) I've been practicing on, and learning on, a variety of new techniques and materials -- expanding on the surprisingly wide variety of materials and techniques called for in theatrical "carpentry."

An aside. As a theater shop person, you knew basic woodshop and carpentry, but you also knew a little bit of finish carpentry and cabinet making, plumbing, simple metal work, welding, soldering, basic electronics, sculpting with several materials, and painting. You worked with plywood, veneer, hardwood, expanded foam, mild steel, muslin, celastic, casting resin.

So I went into this project knowing (more or less!) how to hot-bend metal, how to cut threads with a tap and die, how to sculpt in clay, how to use drill press and bench grinder, and so forth. I still had to learn such things as how to braze, and how to work with epoxy clay, as well as how to apply the techniques I knew without a proper shop and the kinds of tools I was used to having.




As with so many things I've put aside for a few years only to come back to, I'd forgotten how much I enjoyed doing this. I don't know how (or even if) I want to add prop commissions to my list of income generating jobs, but I am already (even as I have another 40 hours to go on the current prop) looking forward to the next prop to build.

Are ee ess pea ee sea tea

I don't act. I took a couple of acting classes in college -- just enough to realize how much craft, knowledge, and damned hard work goes into what often appears so effortless on the stage. I have a deep respect for what actors are able to do, and even more, for the effort and sacrifice they make, often on stipend or less, to appear in shows.

I consider it my humble duty to not add to their work load; to see that what I do with microphones or other technology is as comfortable as I can make it, and supports with the most clarity I can achieve what it is they are attempting to do on stage.

I also am not a musician. Sure, I can fumble around on a few instruments, but I don't have the skill even to sit in a pit, much less be good at it. I have the deepest respect for musicians, too, and make that same humble effort to make them comfortable and support them and see that their efforts are projected into the audience with as much clarity and honesty as I can manage.

My little fumbling around with recorder and crumhorn and ukulele is just enough to help me notice some of the specifics of their needs; tuning strings, wetting reeds, trying to avoid chipping a tooth during fast switches, etc.



On the flip side, they may very well know my job. They may know it better than I do. My special responsibility comes from being the one person who is free to walk about the theater and listen, concentrated, without having to think about entrances or if the tempo is too fast for the dancers or anything else. The person mixing the show (whether it is me or an assistant) is the one person who will be there every night, be there when the curtain goes up, and is thus the only person in position to make certain sorts of decisions about the ultimate sound.

When it works, we communicate that mutual respect and understanding of our individual tasks; I get out of the way of the actors and musicians and allow them to do their jobs, and they trust my ears and instincts when I tell them what it sounds like from out front and what my experienced opinion is about what they should do.

This is, I think, how we have to behave. Being a prima-donna, acting as if your skills trump everything else, or locking yourself in the booth and refusing to establish that rapport with the people who are out on that stage, is a mistake for a sound operator or sound designer.



Today's post not inspired by anything in particular. I opened two shows this weekend (neither of which I mixed myself) but they both went about as smoothly as can be hoped.

What has it got in its pocketses?

After doing the sound thing for years, I finally got it together to start carrying a gig bag. I still can't afford two copies of every tool I commonly use, but it is getting close.

I found some very nice, durable 16" x 12" x 8" shoulder satchels at a local dollar store. The bag stays packed, in the closet, so I can just grab it on the way out the door. It travels with me to almost every theater gig now -- the only exceptions is when I intend to walk for a distance, and repack for a smaller and lighter set of tools.



The front pocket contains the following tools:

White "board tape" and black Sharpie marker (to mark sound boards and cables).
Black Gaffer's tape.
Double-Stick tape.
"Nexcare" micropore surgical tape (for taping wireless mics to actors.)
A "Minty-Boost" AA-powered USB power supply (to power some of my gadgets and charge iPods).
Small VOM (aka Multimeter).
Tweaker -- miniature screwdriver for adjusting the gain pot on wireless mics.
Earpods in a case (for all those times you forget the headphones).
Voltage Sniffer aka "Chicken Stick" (for seeing if there is power getting in).
Energizer headlamp (one of the few brands that has both red and white LEDs)
Goo-Gone, and a rag (for removing tape residue from mics and cables).
Caig De-oxit, aka "tuner spray" (for cleaning dirty connectors).
A notebook and pen.



In the flap pocket, also always there, are personal supplies:

Kleenex pack
Cliff bar
Pepto-Bismol tablets
Ibuprofen
Oragel



There are more tools in the bag itself, but that is a ever-changing collection, depending on the gig in question. Often found in the gig bag;

Cable Tester (I have a nice one to check XLR, 1/4", MIDI, and other common cables)
Earclip Bag; a small mic bag holding coat hanger wire and heat-shrink tube for making earclips for wireless mics).
Headphones.
A couple of microphones.
A spare piece or two of mic cable (since you can never trust the house cable).
Some device to put out a MIDI pulse (a mini-keyboard, or one of my DIY MIDI gadgets).
Multi-band Scanner (good for checking for clear air for wireless, better for tracking down lost transmitters, also nice as a simple source of on-stage sound to trace a mic...plus you can listen to the radio while replacing batteries and wiping down wireless mics.
Computer (when not in its laptop bag).




And then, in my pockets always travel a few basics as well;

Burt's Bees
A hand-cranked Radio Shack mini-flashlight, converted to blue LEDs
A multi-tool (knife, screwdriver, crescent wrench) I found in one of those bins at the counter of my favorite hardware store. I have actually hung and focused an entire show (err, that's lighting talk, not sound talk) with the thing.

And nail clippers I bought in Japan. Not because it comes up often in theater, but rock climbing tends to leave you with a lot of annoying broken and ragged nails.