Wireless Mic Systems - Which frequencies can I use?

How do wireless systems work?

Wireless systems allow you to transmit an audio signal directly from your mic and instrument to your amplifier or mixer, and receive a monitor signal directly to your In-Ear Monitors. These are often used at public events, on stages for live performances and far too often by bands in the rehearsal studio. Can I buy any wireless system and use it anywhere?

Radio wireless mics, instruments & In-Ear Monitoring systems transmit their signal using radio. There’s a variety of frequency options for wireless systems both with and without a licence. When using radio devices, it is important to use the right frequencies. All wireless equipment share frequency spectrums with each other. There aren’t any specific ranges reserved exclusively for your gear, but there are frequencies that are more suitable for different purposes.

It’s worth noting that the acceptable frequencies differ from country to country. The following information is only relevant to UK users.

Over the last ten years, big changes have been made to the frequencies available for wireless use.

"In 2013 the majority of the 800MHz frequency range was sold to phone companies to allow faster 4G mobile broadband."

Before the changes in 2013, most radio microphones operated in the shared space of Channel 69 or in Channel 70. After the sale, it was made illegal to use Channel 67 through to Channel 69.

Which frequencies can I use?

Licence-exempt frequencies include 173.8 - 175MHz and 863 - 865MHz, Channel 70. The downside of this space is that you may suffer from interference due to other users nearby, otherwise known as intermodulation. Channel 70 is deregulated and free to use, but It’s only possible to fit a maximum of four or five systems into this band, and it’s not ideal for larger systems or for IEMs. A further issue with Channel 70 is that 4G transmission occupies the space immediately below 863MHz, and this can cause further interference.

You are required to purchase a yearly UHF UK Wireless Microphone Licence to use Channel 38 (606.5 – 613.5MHz). The license permits use across the UK for yourself and anyone who is hiring your equipment and will set you back roughly £80. Channel 38 is large enough for up to 12 radio systems, but if you’ve previously used your device on Channel 70, you likely won’t be able to retune it to Channel 38, and vice versa. Again, this space is shared by other uses, so you may encounter intermodulation.

"If you’re buying second-hand equipment, it’s important to make sure you do your research first before nabbing a cheap deal."

The alternative to these shared frequency ranges is a ‘fixed site licence’ or ‘co-ordinated’ frequency Licence. To ensure intermodulation-free use, these frequencies are allocated to specific locations and these specific ranges will be dotted around the spectrum. This license is around £40 yearly.

Beyond UHF and VHF bands, at the higher end of the spectrum is the deregulated, free to use, shared space of 2.4GHz. Many radio mics, like the Studiospares Wireless System and the Shure GLX, are manufactured to operate at this frequency range. I don’t recommend using more than 4 - 6 devices at 2.4GHz.

Useful software

There is some very useful software out there, including Shure’s Wireless Workbench 6. This free to download, time-saving software allows you to focus more on your performance and worry less about assigning your devices. You can scan for available, compatible channels for your Shure device, and manage and calculate your frequencies.

I’m buying a new wireless system, what do I need to know?

• What am I using it for? – is the setup going to be a mic for speech and spoken word or microphones for singers and wireless instrument packs for musicians?
• Do you need to purchase a license? Do you need a big clean, interference-free signal, or can you work with a small, license-free range for a handful of devices?
• Are you intending to travel or tour? Have you checked that your chosen frequency band suits your audio and is it legally compliant with the countries you’re travelling to?
• Is the wireless system second hand? – Can the device be re-tuned? Or is it ‘locked’ to a frequency?

Explore our range of Wireless systems and In-Ear Monitors.