Implementing Talkback Functionality

This question relates to creating a talkback circuit that incorporates 2 ATEM switchers and 4 older model Blackmagic Studio Cameras(SDI in and SDI out connections only - no ethernet connection)…

The situation is this:
I have a setup with 1 ATEM switcher (HD Television Studio HD8) that is used for camera management – “shot picking”. This Switcher sends a “production feed” to the input of a second ATEM switcher (HD Constellation 2 M/E) that is used to manage graphics associated with the live production– insert lower thirds, etc..
My current cameras (older model Blackmagic Studio Cameras) have SDI in and out ports and jacks (1/4” and .206 jacks) for aviation headsets. Before introducing the newer HD Television Studio ATEM switcher I was using an older ATEM switcher that had the same kind of “aviation headset jacks” and sent and received talkback over the SDI links.

With the move to the newer ATEM “camera switch” all talkback appears to go through the talkback jack on the back of the switch – just like on the HD Constellation 2 M/E.

I have looked at the pin-out diagrams for the talkback cable in the Blackmagic manuals and while creating a properly “pinned” cable is not problem, I still have the problem (or I believe that I have a problem) of interfacing the cameras with the newer RJ-45 talkback setup - I realize that I will need adapters to adapt the aviation headsets to the 5 pin DIN jacks on the switchers.

Ideally, I would like to be able to tie both switches into the same Production and Engineering talkback circuits and would be able to have all cameras on the “hotloop” AND would like to be able to offer a headset (and get verbal responses from) to a couple of sound engineers who are operating sound boards – the ability to have a 3.5 input jack into the hotloop for input from a couple of wireless headset wearers would be a plus.

I realize that this is a slightly (perhaps very) convoluted setup, and I would be grateful for any advice. I realize that I may need additional hardware – brand and model recommendations will be appreciated.

[Gary Adams]

Hello Thomas. I can help a bit. The cameras get their talkback through the SDI cables to the ATEM. You do not need to modify headsets since they already work in the cameras. The Aviation headsets will not work on the 5Pin XLR in the switchers and cannot be modified to do so easily. You can use one of the many industry standard headsets from intercom vendors if you like. You can interconnect both switchers through the RJ45 talkback connector. There is no cable for this as you must make a cable that carefully connects outputs to inputs. One thing was not in your description but do not directly connect a camera to both switchers or there will be feedback. That could be turned off on one switcher. Even the SDI connections between switchers should have their talkback channels turned off to prevent feedback. I hope this helps.

Gary

Gary,

Thank you for the information and clarification.

I can easily construct a cable to connect the RJ-45 connectors on the back of the two ATEM switchers using the pinout in the manual....Since I am interconnecting two ATEMS, I think I understand your post to mean that I will need to designate one ATEM as the "Primary" unit (the one that the cameras connect directly into) and the other as the "Secondary" unit and create what is essentially a crossover cable to interconnect the units, rather than using a cable with the same pinout on each end?

Concerning the aviation headsets....I have seen some aviation headset (.25" and PJ-068 plugs - the same headsets that work with the older Blackmagic studio cameras) to 5-pin Male XLR adapters on the market....Do you know if anyone has had success in making these work? If I can avoid it, I'd rather not have to discard my existing headsets.

When I mentioned a crossover cable in my previous post, I am curious if I will need to connect the Eng TX+ pin of the talkback connector on the"Primary ATEM" (the one the cameras are plugged into) to the Eng RX- pin, (and etc.), on the Talkback connector on the "Secondary ATEM"

We are shifting to Shure BRH440M-LC headsets to plug into the two ATEMS. This will give us native 5-pin XLR headsets.

[Gary Adams]

Hello Thomas. Usually Tx+ would connect to Rx+ and so on. In a mono system like this reversing the polarity would have little effect but be consistent. So yes connect Tx to Rx. Plus to plus and minus to minus. I hope that helps.

Gary