Radio mics are mics attached to the head that transmits out frequencies received by the sound desk.
Two types of radio mics are:
I’m aware that it’s probably a controversial opinion, but here’s why. I first saw this mic on a youtube clip of someone as the narrator singing ‘Shoes Upon the Table’ from Blood Brothers. I didn’t know what that thing at the top of his head was. He’s supposed to be an intimidating character, but the microphone is too distracting and it ruins the effect. At least I know what a radio mic was so wouldn’t be too busy asking myself what it was.
Frequencies
There are lots of frequencies, but unfortunately we can’t use them all, and there are less available now due to the government selling them to mobile phone companies. Higher frequencies lead to ultrasonic.
Channel 70 doesn’t need a license, however this could mean others could be using it and there could be radio interference.
Channel 38 is reserved for radio mics, but it requires you to buy a licence.
Channel 54 is licenced for Northbrook, but we can only use it at Northbrook. That means that if we do a show in another location, then we aren’t allowed to use channel 54.
Always ask the Sound Designer/Producer for what channels you can use.
The Receiver
(note: The transmitter is usually from the desk and the receiver is on stage, but with head mics they sort of do both, so it gets complicated)
When you have the receiver, you need to turn it on. Open it and switch it on. Make sure you check the battery level. The batteries will be your worst nightmare.
Then you set the sensitivity. You can do this by going to menu, selecting sensitivity and speaking in a loud stage voice which will register on the transmitter. If the average sound is between (I think) 10 and 20, then you ok. If not then push the + and – buttons until it is.
Next, the sound check. It’s the same as a regular sound check.
You can also use the equaliser to sort out the voice, like it the person has a cold or to sort out popping. Get the person to say pops and plosives to get them to expel their breath onto the mic. If you hear a pop, go fix it. Unfortunately my mic wasn’t popping so I never fixed it myself and don’t know how it is done.