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Rolling Your Own Wireless Communications System?
nuggetman asks: "My high school, like most others, has a theater program. One critical element of the show is the tech crew - the group of people behind the scenes who keep it all running. Communication between the stage manager (myself) and crew members (as well as between crew members) is critical. For this job right now, we're using standard hand-held walkie-talkies. They get the job done, but they're susceptible to dead batteries, incompatibility between VOX headsets, and interference from janitors, the office, hall monitors, and even the local McDonald's. We've been wanting to invest in a theater-communication system, but they can run extremely expensive. Is there any hardware out there that could use a standard PC (Linux or Windows) and some wireless headsets to roll your own communication system that could cover a long enough range (say the theater which is the size of a gym plus a decent range outside it) at a low enough cost? Our school just installed 802.11b/g throughout the hallways, so we could tap into that if necessary and add our own router near the stage if we had to."
Sorry, wrong company. I meant Vocera.
http://www.vocera.com
Your best bet for cost and effectiveness is to get nicer walkie-talkies. At $40/pair Motorola FRS/GMRS radios have 22 channels, and a 2-mile range, plus you can get headset/microphones to go with em. I own a couple pairs and they're durable as hell (you shouldn't drop them in a lake, but mine came back to life anyway) and have 12+ continuous hrs on a couple AAs. Plus now you can multichannel your crew - Ch 1 is Lights/sound Ch 2 is backstage crew.... ~J >-- I'm not a pessimist, I'm a realist. It's not my fault that life sucks so much. --
-- I'm not a pessimist, I'm a realist. It's not my fault that life sucks so much. --
I'll second this suggestion.
When I was in high school, we used RadioShack walkie-talkie type headsets, with both press-to-talk (PTT) and voice activated mikes. We were always dealing with dead batteries, dropouts, and the voice activated took turns being either too sensitive, or not sensitive enough for volume the stage manager neeed to speak at (fairly quiet, sitting just off stage in the wings).
We even had interference from a Fischer-Price baby monitor, and spent an afternoon walking around the neighbourhood near the school, knocking on doors and asking people if they had any babies. I don't want to know what they thought.
The next year, we got a set of wired ClearCom headsets, and all was good in the world.
The signal was clear, and reliable.
Because they were "the" standard brand, we were able to borrow extra equipment from the local theatre company when we needed an extra headset or something.
They are also good, 'cause unlike the walkie-talkies, they come either with 1 or 2 earmuffs and do a good job of cutting down on outside noise (useful if you do bands or concerts).
Spend the money. It's not that much, espcially when you consider (1) that they'll still be chugging along in 20 years, when the RadioShack stuff is lucky to make it through 20 weeks, and (2)over those 20 years, how much are you going to be spending on batteries which you need to replace each show (you are using a fresh set each show right?)
Also, we rented them out to other groups occassionally, so you get a source of income.
Do it the right way, you won't regret it.
E.
Basically, it mimics a standard phone line, and any telephone device you plug in can communicate with the others. You can run long cables and use splitters [nearly] to your heart's content. For about $30-$50 per station (hundreds less than a real, however superior, Clear-Com system), you can purchase corded or cordless headset telephones which work nearly as well.
If you do that, be sure to get phones with mute capability; and if you go cordless, be sure to check on battery life and try to get phones that don't beep too loudly. You might even need to disassemble the cordless phone and disable the internal beeper to make it silent.
Two things that are really nice about true Clear-Com systems is that (1) they can be operated silently (i.e., without beeping), and (2) their mute/talk controls can be operated by feel alone -- you don't need to look at a mute LED to determine whether or not you're muted. Those features are hard to come by on unmodified corded and cordless phones.
In general, a theater intercom system needs to be absolutely reliable, and should also be full-duplex (which walkie-talkies are not, but telephones are). I'd shy away from creating a custom wireless soultion with unproven technology -- it will take much more time to develop and won't be as reliable. If anything goes wrong during a show, or if reception isn't good enough, you've got big trouble.
You obviously have no experiance in theater. Techs are expected to do anything from crawling out over suspended ceilings to crawling under a stage or running up and down stairs during a performance a laptop in any sort of arrangement would get in the way and be easily broken, nevermind that for the price of a few laptops you could buy a real system from someone like Telex or Clear-Com. I would suggest visiting ControlBooth.com and asking this question in their forums to get some practical suggestions. These are people who actually work with this day in and day out so they have real life experiance. Here's my idea to do this on the really cheap. It's not that hard to build a private phone network that doesn't actually dial but works like a party line, just put some voltage on the line. Get yourself a bunch of cheap cordless phones that allow headset use and lock the phones on so the line is always open. It's far from perfect but is the closest thing I can come up with off the top of my head. Don't take my word for it visit ControlBooth.com and ask in the forums, they're good people and know what they're doing.
Gaaah!!! No, no, no!!! 5 watt transmitters in a backstage environment?!? I recently had to completely ban our Motorola 2-watt radios from the booths in both of our theatres, because when someone tried to talk on them, it would often induce RFI into the sound equipment, headset system, and, worst of all, the light board. You key up one of those things next to an unbalanced signal line, and *everyone*'s gonna know it. :)
In a theatre, nearly everything is temporary - speakers need to be in this spot for this show, then, six weeks later, completely across the room - hence, most cabling and playback/processing equipment is portable, and certainly not run in nice steel conduit - which, sadly, leaves it susceptible to RFI.
Yes, I've also banned the use of cell phones.
(Master Electrician, Arden Theatre Company, Philadelphia, PA.)
If all the world's a stage, anyone who says they want better lighting spends far too much time in a dark theatre.
Damn, I already commented, and thus lost my ability to mod, so I guess I'll just add a "Me too!" post, to support the parent and grandparent's posts. Backstage communication is really, really, not a complex issue anymore. It's been solved, and solved well. Clear-Com, Telex, and Production Intercom all make extraordinarily reliable products just for this purpose. Yes, they're expensive, and yes, they're worth it. :) )
Having a cue get missed because your batteries died, or because someone is DDOS-ing your 'intercom server' is just plain unacceptable.
If money is really tight, check ebay - I wouldn't be the slightest bit surprised to find used intercom gear on there. And really, all you need is a base station and a couple of beltpacks and headsets. If you're really cheap, buy raw 2-conductor shielded cable and 3-pin XLR connectors and build your own cables (that's what I do
If all the world's a stage, anyone who says they want better lighting spends far too much time in a dark theatre.
First off, let me preface this by saying that i have worked building large-scale theater shows, and as a lighting designer for 7 years. I have worked on shows including the Lion King, Cher, Phanton of the Opera, Miss Saigon, Tim McGraw, the Pan American Games, as well as numerous regional and touring theater shows and outdoor festivals.
Quite literally the only thing these shows have in common is the need for clear, reliable crew communications. During setup/strike (installation/teardown), crews usually have portable radios (Motorola Walkie-talkies generally), so everyone can keep in touch without shouting or running around looking for each other. Essential for big shows, unnecessary but nice for small one. However, for all shows, only "Clearcom" communications are used.
Clearcom is a brand-name of wired "party-line" communications sets. It's used generically for other brand systems, like Telex, HME, etc. It's the same thing you see camera operators on TV shoots wearing. Everyone has a headset and beltpac, and can talk to one another on a common "channel". Everything is hard-wired, and everything works, all the time, every time. The systems is used for calling show cues, as well as any other necessary communication during showtime.
However, the "wired" issue becomes a problem for some people. While audio and lighting techs can often stay put (they sit behind a board), stagehand/stage managers have to be mobile, often on stage. Usually they need to be able to communicate in a high-noise environment, and it must work reliably.
The only way to do this is via a wireless clearcom system. Telex, HME, and Clearcom are the big three, and all of their systems are inter-operable. I personally like HME's RadioComm, but all systems have their own benefits. Simply put, these systems are expensive but necessary. For a school situation, you can probably get away with 2 wireless stations, and 4 wired. But you can't cheap out on this. You need great headsets, and equally good beltpacs to go with them. When you're midshow, and you can't hear your cue, you'll know why.
I hope this helps. I realize that you were looking for a cheap way around the problem, but there isn't one. You'll find that with 95% of things in theater, cheaping-out never works. You buy a crappy light, or sound equipment, or cleacom, and life sux but things go on. You cheap out on rigging or construction, and people die. It's as simple as that.
-Michael Roy
-Michael Roy Some people are like Slinkies. Not really useful, but you can't help smiling when you see one tumble down