Radio Frequency Scanning and Software

Part of putting on any large scale show is having ample radio microphones that work and are able to talk to each other. How do radio engineers know if they are working and able to talk to one another? Part of that is making sure all of them are on the right frequencies and not interfering with other sources.

Other sources of audio that could interfere with the quality of the show are as different as each show that is put on in theatres. These other sources are put into categories to make it easier to identify where they could be coming from. This is part of spectrum management and one of the first steps a radio engineer will do as part of their preparation process.

Audio engineers will use a radio frequency spectrum analyser to visualise the frequencies of their devices so they can measure the strength of the signal over frequency bands. Most  shows in America operate between 400-600 megahertz while most shows in Europe operate between 470-698 megahertz. To put this into perspective, most television stations around the world operate from 300-700 megahertz. This means that, naturally, television stations are going to be the largest problem for setting up frequencies for wireless microphones. 

Radio engineers use what is called ‘white space’ which is the unused frequencies between everything that is being used on the frequency band, like television stations. The easiest way to set up wireless microphones in these white spaces is to cluster all the wireless microphones needed to one end of the band and all the in-ear monitors to the other while keeping any spares and back ups to somewhere in the middle. This helps separate what is needed in the show with a quick set up and can be easily found later if there are any issues.

These days there are lots of applications and hardware to help find these white spaces that shows rely on for their microphones. However, major city areas have the most difficult time finding these white spaces as they are in the centre of where the signals are originating from. Shows on Broadway, the West End, Paris, Sydney and Hong Kong have specific equipment they use to ensure their shows won’t receive interference from the bustling cities they call home. 

The most common way to get this specialised software is directly from the companies the microphones were from. Sennheiser uses their Sennheiser Wireless Systems Manager (WSM) that allows companies to remotely control and monitor their wireless systems. Shure uses Wavetool and Wireless Work Bench (WWB). RF Venue uses the RF Explorer. Sony Pro uses DWX Wireless Studio. These are some of the best companies where some of the best in the business utilise some of the best equipment.

While scanning frequencies is one of the first steps taken for radio engineers, once they have found the white spaces they can use there are still several steps that need to be taken before the wireless microphones are ready for opening night.

All images used were created by the author.

Drew Janine

Live Sound Engineer -EUROPE

Janine has always been a part of music and performing. The first show that inspired her to go into theatre was the Velveteen Rabbit which she saw as a child, and Drew works to keep that magic alive as working behind the scenes in theatre as a live sound engineer. When Drew was accepted into an internship program for audio engineering at a recording studio, she jumped at the opportunity. That was at the start of 2020 and so much has happened since then, both in her career and in the world. Since then, Drew has taken several opportunities to work at recording studios, concerts, festivals, and even large theatres while spending time on tour across the North American continent and Europe. Drew’s favourite by far though has been the chance to work on Broadway and West End shows, as this was a dream come true. Drew is honoured to get to share these experiences from being inside the entertainment industry and hopes to inspire others to continue working in theatre.

Back to Home