Digital Vision - Making a Visual Difference

Which Wireless Microphone solution is best?

We often get asked, which wireless Mic solution should be used in a school?, What’s the difference between C.70 & C.38?, Why do we have to have a licence for C.38?.

Licence free solutions
The solutions below can be operated without the need to purchase a licence.

Channel 70 (863-865MHz) sits on the TV Channel spectrum and is a de-regulated and licence free frequency. Channel 70 offers a maximum usage of 4 microphones or in-ear monitors up to a distance of approx. 50 metres, further distances can be gained with antenna amplifiers. Interference is more common on this frequency from electronic devices such as mobile phones & computers.

2.4Ghz ISM (industrial, scientific & medical) also shares the same band as Wi-Fi, Bluetooth and other wireless devices, the human body absorbs and blocks this frequency and it’s essential to maintain line-of-sight between mic & receiver. Microwave Ovens can produce local interference to this band. like Channel 70 this is also a licence free frequency. In theory, it is feasible to simultaneously operate up to 8 microphones in one location under optimal conditions, however local interference in the 2.4GHz band will often reduce this number to 4 or less.

1.9Ghz DECT (digital enhanced cordless telecommunications) is pretty much the same as the 2.4GHz band in that it’s a very crowded band, mainly sharing its band with cordless headsets and phones.

Licenced solutions
It’s a requirement by law to be in possession of a licence to legally operate radio microphones or in-ear monitors in channel 38, information regarding this licence can be found and purchased from the Ofcom licencing home page, currently this is £75 for a 1 year licence or £135 for a 2 year licence.

Channel 38 (606-614MHz) is the replacement Channel 69 frequency, channel 38 is a licenced band as it sits on the DTV Channel spectrum, a low cost licence will need to be purchased from Ofcom to operate this solution. Radio microphones and in-ear monitors use this band. Channel 38 solutions can support up to 12 microphones or in-ear monitors in a single location.

Hopefully this brief overview will answer the questions you have, if we’ve missed anything please feel free to call us on 01442 620078 or drop us an email