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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
While you could probably roll your own system with a lot of work, you are better off going with a real Clearcom system for theater use. They do both wired (cheaper, but it's really all you need for high school) and wireless (quite expensive). eBay often has some used eqipment you can buy as well. These systems are what are actually used in the field, and in many schools as well and are quite less likely to fail than a home-grown solution (rebooting the communications computer in the middle of a show so the SM can talk to a board-op is a very very bad idea). It may seem easier to put together a free system than buying the Real Thing, but by the time you purchase wireless eqipment and setup a custom system you have spent more in time and money than you would with a real system.
$800 for a CS-222 ClearCom 2 Channel Main Station is a lot of money, so another thing you may want to try are Motorola TalkAbout radios with headsets (not in VOX mode though, you don't want that in a theatre since you want to avoid unintentional chatter on the comms system). They tend to have fairly good range in my experience and if you take the time to pick out clear channels there isn't an issue with interference).
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.
I would suggest that you CANNOT get a "quality" two-way radio for $20 (unless it is stolen).
If a wired solution is okay, I would recommend Clear-Com. As an earlier poster mentioned, they are reliable and sturdy as hell.
If you need wireless, I would skip the Clear-Coms, as they are bulky and don't have great range. Spend an extra couple of hundred and get a Motorola EX600XLS. They are high quality, small and light, and I think you can get 8-hour NiMH batteries.
Been there, both in HS and college. Is there a particular reason it has to be a wireless system? We used wired ClearCom systems at both. Sometimes the cord was anoying, but usually it was not a problem, and it eliminates the VOX, noise, dead spots, etc. problems. A quick search found thisc h has some packages by Production Intercom that arn't too bad price wise, and you can probably find used equipment out there for less (eBay had some real ClearCom gear last time I looked)
http://springtree.net/pi/econocom.html
whi
I'll bet there is more than one large church in your town, and each one has wireless gear that they use for services sunday morning, and no other time. Just talk to them in advance and borrow their gear. Most would be more than willing if you ask correctly. (and take care of the equipment)
Note that there is an art to asking. Best is to have someone in the production (actor, teacher, think outside of tech crew) ask. I'm not sure about much else because as a tech guy I don't know how to ask.
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.
Brilliant one-way communication that still requires physical wires running all over.
Run several wires instead of one, and put telephones on each end. Telephones work uphill also.
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.
I used to work at a theatre which had those Radio Shack wireless headsets. What pieces of crap. They were actually *worse* than nothing. Completely unreliable - I'd have no clue whether the person I was trying to talk to was there or not. They also really, really, liked to break. Usually at the 9v-battery connector, since the batteries died so quickly and had to be replaced so often. You can only solder those things back on so many times...
If all the world's a stage, anyone who says they want better lighting spends far too much time in a dark theatre.
I actually really like the wired clear com. There are no batterys to buy, and no interfearance.
The audio quality is as good as anything out there, the system is full duplex, so you can talk over each other. It uses standard xlr cable, so if you have a house snake you can just run it along that.
Try to get a used system, the equipment lasts forever.
My only warning about clearcom is to make shure that you don't have any short's in you cables, they can bring down the whold system. Also be cautious running it along with electrical cables, they can induce hum.
We use clear com during all our major preformances. We back it up with gmrs, wihch is another option, think of gmrs as being super walike talkies, the big benifit of gmrs is that you are assigned your own channel by the fcc, and the range is a few miles.
The wired clear com is still the standard in the entertainment industry, gmrs is also popular for non preformance comunication, but almost evryone I know of uses wired clear com for preformance.
Get the most basic clear com unit you can find, and a few headsets, you can expand to more headsets when you need, they'll be available just about forever.
Well art is art isn't it, but then again water is water; and east is east; and west is west; and if you take cranberries
I do tech at my HS (sound), and we have both clearcoms and those cheap radio shack things. The radio shack wireless system sits in the boxes, unless we absolutely need another headset. The clearcoms work excelently, no interference. Only thing is they're like $500 per beltpack & headset, so it can get costly. Our sound system was installed with one in the sound booth, light booth, and stage left. I later added one for stage right/pit (in a musical). Right now I'm working on getting the school to shell out the $7000 I want for wireless microphones...
Considering ClearComm vs. Telex, I would go with Telex. It is compatible with ClearComm (unbalanced), but more importantly, it is balanced, so you will have less noise in the system. Also, the standard connectors are balanced 3-pin XLR, meaning they are compatible with balanced audio cables (However, I would buy a separate set of cables for intercomm use, and make them a different color, like blue - Clark Wire & Cable. This makes it easier to identify which cables are audio and which are intercomm and also ensures you won't use a beat-up intercomm cable for audio!). Also, Telex beltpacks are more rugged (metal, not plastic), and they look better! Look at Full Compass for intercomm hardware. They have good prices. Hope some of this is useful.
FreeHeel
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
My school always used Clear-com's. They're not incredibly cheap, but certainly better than a PC. You also don't need to go all out and get a real base station...the portable one does nicely. BenFranske is right that people need to be all over the place, but they don't always have to be connected. We had someone on each side of the stage, the people running the boards, and the stage manager all connected. The stations are wired together, but it shouldn't be hard to find someone to run the XLR for you, or you can just run it through your normal audio snake.
I work on my schools television station. Anything big like recording the school plays we usually do FRS radios. I've seen other setups use the unused 2-pairs of wire in the CAT5 network ports in the school as the local loop in a homebrew intercom system.
Use those Motorola radios that get like 1 mile range. They're like $50 for a pair plus $10 for some headsets to plug in. That's what most high school theaters use, cause they're cheap, work well and are simple to operate.