basic talkback system

[Tigglet]

I have been looking for a way to talk to people backstage without spending a fortune. it was suggested to me last week that all I needed was 2 headsets and wire it in using the aux send and return feature on my mixing desk (LEM compact 12-8) I have several spare channels as well as aux send and ret for aux 1 and aux 2. I need help working out several things

 

1 what headset to go for canford do their own for £85 ea

 

2 what connectors to put on the headset as I will need to run them 50-100m I think I need balanced for the mic section at least

 

3 on the desk how do I wire it up. my channels each have balanced and unbalanced inputs the aux send and ret are 1/4 inch jacks.

 

I must add that I am a teacher who has been dropped with the pleasure of doing the technical side of the school theatre so I am learning on the job so to speak.

 

Thanks for any help or ideas.

 

ABT :huh:

[henny]

I have been looking for a way to talk to people backstage without spending a fortune.  it was suggested to me last week that all I needed was 2 headsets and wire it in using the aux send and return feature on my mixing desk (LEM compact 12-8) I have several spare channels as well as aux send and ret for aux 1 and aux 2.  I need help working out several things

 

1 what headset to go for canford do their own for £85 ea

 

2 what connectors to put on the headset as I will need to run them 50-100m I think I need balanced for the mic section at least

 

3 on the desk how do I wire it up.  my channels each have balanced and unbalanced inputs the aux send and ret are 1/4 inch jacks.

 

I must add that I am a teacher who has been dropped with the pleasure of doing the technical side of the school theatre so I am learning on the job so to speak.

 

Thanks for any help or ideas.

 

ABT :huh:

<{POST_SNAPBACK}>

 

 

 

one v cheep / simple option involves using phones,

 

connect in parrell 2 phones (pins 2/5 in a phonesocket) and 9v pp3

 

there you have it , full duplex coms with sidetone, the only thing to bare in mind is the more phones the bigger psu u need

[paulears]

Reading between the lines, I'm guessing that what you want to do is to be able to talk from behind the desk to some people wearing headsets on stage, and to hear them.

 

I you want it to be a reliable, but workable bodge, then your idea is basically ok. Take a headset with two earpieces (for ordinary stereo). These need fitting with a conventional stereo plug, to go in the mixer phones output. Wire the headset mic to a desk input with fader off, and prefade send up. At stage end, runing off the send, use a small (hi-fi type) amp capable of a few watts (20w would do). Take the speaker output via a 20 Ohm resistor (something between 2 and 5 watt rating would do) direct to each headset. The mic output from the headset simply gets plugged into a normal mic input, going back to the desk. Many headsets may only have an unbalanced output - connect pin 1 & 3 to ground, signal to pin 2 - no phantom. On the desk, the send sticks your voice into the headsets, and once you have their mics plugged into desk inputs (with fader off, as above) you can press the pfl/solo button to hear them. If the stage end headset connections are made in a small diecast box, you could fit a mic on/off switch.

 

It is a lot of work, and as you say, the headsets are not quite budget items, so adding in an extra £100 ish for a bp111 or similar, may simply just be better value. If you build it yourself, the boxes, headsets, cabling still have a price. The advanage of this system is that you can use the desk pfls as usual when you need to. The disadvantage is that the individual stations get no side tone or ability to hear the others unless you also send a bit of them back via the send, and then things start to get a little more complex. I have done this before, but have to admit that it isn't anyway as simple as buying the proper thing.