Intercom

[dogcop]

Good evening all.

Time for a bit of brain picking.

We are looking to source a talkback system for our church in order for the stage manager / producer to talk to soundies and lampies during our services.

 

The system would be preferred to be wireless.

 

What do you use, where can I get them from,how do they work and price ? :)

 

When I say how do they work, I quantify that statement by meaning can you buy 4 headsets all on the same frequency as a closed system or do you have to buy extra belt packs or receivers. I hope you get the gist ?

 

Any help would be appreciated

 

Andy

[Ben Langfeld]

Why do you want the system to be wireless? Your board ops shouldn't have to move, so that's them on wires, so your stage manager is the only one who would have to move. The two biggest (as in most used) systems are Canford's TecPro (in this country) and ComClone (in america). As far as I know, there are wireless interfaces for both companys systems, so what you would do it setup your wired network (power supply + beltpack for each board op) at FOH, along with the wireless tx/rx base station. Your SM would then use a wireless beltpack. The other alternative, if it's a long run between FOH and the stage, is to put the tx/rx base in the wings and run a single mic cable from FOH.

 

Hope that's of some help.

 

See here for more info.

[Neil Frazer]

The common wired systems are Tecpro and Clearcom. Wireless options include Telex Radiocom, a high end full duplex wireless comm system that uses one frequency to transmit comms to all the beltpacks and individual frequencies to recieve comm from each of the beltpacks. it is possible to connect wired and wireless together if necessary.

 

Another option is to use Motorola radios in duplex mode. You would have to have them programed to work in this way but they work well if used with a headset. You would also need a base station and antennas. Again it is possible to integrate this with a wired system.

 

Whichever wireless option you go for you will probably need a licence to use the frequencies.

 

My question is do you really need wireless? It cost a lot more than wired.

 

tecpro availiable from canford audio

Clearcom availiable from Autograph Sales

telex

 

PS. I've never herd of comclone and I work in america...

[mac.calder]

ComClone is a name given to clearcom clones (usually based on schematics available on the net)

[paulears]

it is important to note the differences between simplex, semi-duplex and full duplex.

 

Simplex radio is single frequency operation - as many as you like, but only one can transmit at a time. In practice people constantly talk over each other. When you transmit, you cannot receive anything - silence in the cans of the person talking. In use, people on the intercom ring have to make a concious decision by prodding the call button, or a manual tx button on the sm desk, to tranmit the audio on the intercom ring - AND switch it off, ready for the reply - this is difficult to make work properly, if the ring is switched to tx and somebody forgets to switch it off again, then the outstation can't reply. Not very good.

 

Semi-duplex uses two frequencies one for receive , the other for transmit. The advantage being that intercom audio can be transmitted permanently. All the receivers hear the audio on the intercom ring. Pressing transmit, or using the awful auto tx facilities returns the outstation audio to a separate receiver, going to the ring for everybody to hear, including other radio users. The only real disadvantage is that you have to push a button - auto tx waits for sound and keys the transmitter, resulting in the first syllable being clipped. Users often develop a pfff in front of their first word to ensure it gets through, as people on 'real' comms get really fed up with hearing "..oh" - "was that go?", "..ess", "why didn't you say so, I didn't get it", "..ugger"

 

Full duplex is the goal - exactly the same as on a wired outstation. Much more difficult. In analogue radio systems this means a different frequency for each oustation - every set receiving on the same one. This is difficult to achieve with available channels already being squeezed. Digital systems allow data to go both ways, sent in small packets, with a system of checksums to make sure what is received is valid. So even when a few clash, the system knows and repeats them - the data gets reconsituted into proper audio. There are a number of problems with digital - main one at the moment is cost, but that will get better - the ones I've tried (which oddly are now not about any more) suffered from poorer quality audio. The snag is data rate - reduce it to make the system workable, means poorer resoluton and a narrower frequency response. You could do it with CD quality 16 bit data - great hif-fi quality comms, or you could do it at a low bit rate, band limited, but this would be tiresome to listen to for a long while. At some stage we will get a happy half-way with good quality and cheap prices - just not yet.

 

Last thing - as in audio systems, there is nothing as reliable as a piece of wire between source and destination. Radio can be good, but NEVER as good. It can come close, but even ignoring the technical aspects, the damn things run off batteries, which need charging. How many people have never picked up a radio handset, done a quick radio check with somebody else, and by the time you have walked to the place you want to be, not experienced a battery going flat?

[Ben Langfeld]

Oops, sorry, that was a typo. I did mean ClearCom. Apologies...

[GridGirl]

Last panto we hired in a couple of sets of radio cans - I think they were DigiTalk, something like that? Whatever they were, they integrated perfectly happily with our TecPro system (but the radio mic receivers didn't like the cans transceivers being anywhere near them!). They were a lifesaver in a lot of ways (stopped me from clotheslining myself and several cast members!) but they were also a PITA in other ways. We were using rechargeable batteries (obviously!) and we never knew how long the batteries would last - me and the other guy using radio cans always had a spare set in our pockets, because they'd die without warning. Some shows one set of batteries would do fine, some shows it was three sets. Something else they'd do is just stop working - if I unplugged the headset, took the batteries out, put the batteries back in, switched the unit on and plugged the headset back in (you had to switch the unit on before plugging the headset in - go figure!), they'd work again. I would definitely have preferred wired cans, but it was just not practical for what I was doing on the show. I did have a set of wired cans by my pyro controller as a backup in case the radio cans spat the dummy at an important moment though, and they got used more than once.

 

What I'm getting at is that IMHO, wired cans are cheaper and more reliable and often easier, depending on the application!

[dogcop]

thanks for all the advice so far its really helpful.

I've checked some of the makes and models you have suggested and to b honest they are going to be too expensive - bearing in mind we are a church and the pressure to spend what limited resources wisely.

 

However I was thinking that in my real job in law enforcement we use radios all the time. Has anyone ever used a walky talky set with headset for talk back from FOH to teccies.

Looking at prices its going to be cheaper to get three handsets and and three headsets rather than a professional wired in system. Obviously make sure that the frequencies aren't the same as the radio mics - now that would be hilarious !!!

 

I only say that because we hope to move to a new venue in a couple of years which would have a professional talkback system installed from new, so in effect this is a stopgap for the next 2 years.

 

ANy ideas whether this would work ok or have I missed anything blindingly obvious.

If this case is ok any suggestions with a budget of 300 quid

[peternewman]

If price is an issue we managed to get the ASL Intercom stuff cheaply from 10 out of 10, certainly it was cheaper than the TechPro stuff, and it's stood up to use once so far okay. Also you can swap from a master station to a power supply unit to save money.

[Tomo]

However I was thinking that in my real job in law enforcement we use radios all the time.

Airwave no doubt!

The cost of the actual handsets would terrify you, and they are totally reliant on mobile phone masts.

Has anyone ever used a walky talky set with headset for talk back from FOH to teccies.

Yes - and hated it.

Licence-free cheap kit is awful, and half-duplex which will require your users to use proper radio protocol - while you won't have any trouble, your fellow volunteers may find it difficult.

 

I only say that because we hope to move to a new venue in a couple of years which would have a professional talkback system installed from new, so in effect this is a stopgap for the next 2 years.

Well, the Tecpro and Clearcom base stations are simple rackmount systems (2U IIRC), and are therefore very easy to transfer between venues.

The headsets and beltpacks are obviously portable, and such systems are expandable as budget becomes available.

 

You needn't bother installing the cable in your current venue - all you have to do is run a single XLR cable to FOH for the FOH crew, and sit the base station wherever convenient.

In many situations you can use one line in the audio multicore.

[Johnno]

Could you use ordinary mobile phones?

[Big_L]

Mobiles might not be such a good idea as they can cause interference when they recieve and make calls, the infamous 'de de du de de du' noise!

 

Lewis

[paulears]

you've got to decide what you want them for - occasional cues? as in can we start? - yes! or complex show running cues.

 

There is nothing to stop you using walkie talkie style radios, as long as you can live with the fact that if somebody has the ptt button pressed, nobody else can talk, no matter how urgent. Do you actually have a hand free? hiding behind a piece of scenery ready to push with both arms does make pushing a button a bit iffy. I know plenty of theatre with the stage crew on motorola radios and the static people on real comms - it works, and with care and attention, quite well. Given choice, I'd have a wired system, but most things can be pressed into service. The things to avoid are pmr 446 units - only a small amount of channels that can be used, and in a built up city area, you even get people who chat on them for hours on end, which does wreck your cues a bit.

[Peter Chivers]

As well as the famous two systems (TecPro and ClearCom) CPC also supply some budget wired intercom systems. I don't know if these are compatible with either of the big two, but for a self contained church they may just fit the bill.

[cedd]

I've just got drawings and pcb layouts off of the net for the comclone system. Looks nice but was just wondering if anybody else had built a set from these drawings and resources? Don't want to set out and buy everything (as I may as well buy all the bits for a full set of 5 or so) if there are issues with it working.

 

Reliable?