Raspberry Pi

The Brief

The brief was to implement a wireless system into the theatre’s existing wired communications system to allow floor and fly crew members to have access to the wired communication system. The current system implemented at the theatre was one-way communication, using an FM transmitter. The FM transmitter took an audio feed from the existing JANDS compatible communications system. The FM Transmitter then broadcast this audio via an FM signal to mobile phones with FM receivers built-in. This meant that the floor and fly crew could hear the audio on the Communications system, but they were unable to talk back, which became a real issue at times for the stage manager and technical staff.

The Problems

The current mobile phones were old and starting to fail. Screens were failing, the headphone jacks on the side of the phone were flaky and the signal at times was flaky and full of static and other background noise. The theatre only had a limited number of these phones and with the failings, left them with only 4 working units. This was not enough, especially when musicals are playing in the space, as crew numbers on musicals are quite large. COVID has also become an issue for the sharing of devices and headsets, so it would be great to come up with a solution that also addresses this issue.

Can we work with the existing solution?

We investigated the existing system and whilst we could have looked at improving the signal quality at cost, it didn’t solve the issue of not having enough receivers to go around. We investigated the option of buying more phones with FM receivers in them, but it would seem that there are very few phones, generally non-smartphones, available with FM receivers built into them, and those that we could find were still quite expensive. Surely there is another option?, sure, let’s look at regular FM transistor radios or headsets with FM receivers built in. Turns out these are nearly as expensive as the phones. Not an option for our budget.

Either of these solutions would still only allow for a one-way listening-only wireless communications system. It also doesn’t address the COVID issues with sharing and sanitising common-use headsets.

An alternative solution

To address the COVID sharing and sanitising issue, it became obvious that we needed to implement a solution where individual crew members could use their own devices and headsets with the solution.

Our solution should be an improvement on the existing system, by allowing two-way communication. It needs to run on a multitude of devices, phones, tablets, laptops etc, to allow ease of access to the solution, and it should have a low cost of implementation.

Introducing SonoBus

SonoBus is an easy-to-use application for streaming high-quality, low-latency peer-to-peer audio between devices over the internet or a local network.

We contemplated utilising an old phone or tablet as the main communications interface but decided that for better usability and a more professional solution we would use a desktop computer to host the SonoBus session. The theatre managed to source an old Apple Mac Mini for this project. We loaded SonoBus onto the Mac Mini and after connecting to the internet we had a working SonoBus instance on the Mac Mini. We tried to utilise the inbuilt audio jack, but this introduced noise into the system. The solution, the Behringer Uphono Ufo202, is a low-cost analogue to digital interface. We could then split the existing Communication Systems audio into and out of the digital interface. This enables us to also use the system for other purposes utilising the onboard audio jack.

The theatre has its private group on SonoBus allowing crew members to join the same group utilising the Sonobus application on their own devices. After tweaking some settings and setting priorities the crew now has a two-way, wireless communication system for an extremely low cost.

The Future:

The theatre is currently testing the system and after a few tweaks of the original settings, is happy with the outcome. We may look to install Sonobus on a Raspberry Pi to replace the Mac Mini, freeing it up for other future tasks.

For further information or to book us to help with your integration of this product, please contact us via email: show [at] donhardt [dot] au or reach out to us on Facebook or Instagram.