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."

Comments

Easy solution

[Anonymous Coward]

Use yelling. Everyone comes equiped with all the right hardware. No sweat.

Back when I was doing this at school

[Space cowboy]

... which was admittedly about 18 years ago, we were happy to have the very latest technology... microphones and headphones (well, it was on a school-sized budget :-)

To be honest, I'd be surprised if WiFi would help you very much - it'd have to be a VoIP network, which isn't an obvious use of WiFi (the range is too short - most people would simply shout!)

Bluetooth might be an option, but they're basically clever walkie-talkies. Buy some rechargeable batteries and carry them. Sometimes the "clever" solution is the low-tech one...

Simon.

A solution

[The Human Cow]

Some of my friends and I make up the A/V crew at my school, and I came up with an ingenious solution yet to be implemented: a zipline. The A/V booth is about 20 feet higher than the stage and a good 75 feet away, and we decided that a zipline would be the best way to get down to the stage to tell somebody something important.

I guess if you need to tell somebody something who's level with you then you'd have to invest in some model rocket engines or something.

ClearCom?

[Arcady13]

Just buy a few ClearCom headsets. If wireless costs too much for you, get the old-style models and some lengths of XLR cable. Why waste time with all this computer stuff? It just complicates things. Use the simplest solution.

Re:ClearCom?

[elsilver]

Just buy a few ClearCom headsets. If wireless costs too much for you, get the old-style models and some lengths of XLR cable. Why waste time with all this computer stuff? It just complicates things. Use the simplest solution.

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.

An excellent wired/wireless solution

[mdkemp]

For a theater group with which I work, I built an inexpensive intercom system that uses standard corded or cordless telephones. The [simple] schematics I used can be found at http://www.epanorama.net/documents/telecom/telepho ne_intercom.html -- just scroll down to the "Theatre intercom circuit".

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.

Re:This is easy!

[BenFranske]

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.