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 hello@dvav.co.uk.