Radio Mics

This page will introduce you to the use of radio mics in the studio.

Introduction
Setting Up
Fitting the Mic
Microphone Etiquette
Best Sound
How to Fit the Mic (link to mic placement page)
In the Gallery

(Issues related to their use on location can be found under the location filming pages.)

IMPORTANT

Radio mic frequencies are subject to strict regulation through licences. The frequencies on our radio mics must not be changed.

As with all equipment, please take care of the radio mics. The transmitter belt packs get a lot of use and should be treated with care so that the mics, clips, cables and connectors do not get damaged.

Introduction

The Bath Spa TV Studios are equipped with a set of six Sennheiser personal radio mics, sometimes called lapel mics, clip mics or lav mics (short for lavalier). A small microphone capsule is attached to the contributor’s clothing using a small crocodile clip and the wire is hidden under their clothing. It goes to a belt pack transmitter which is powered by two AA batteries. This fits either on a belt or waistband, goes in a pocket or can be held in a pouch tied round the speakers’ waist.

The transmitter sends a radio signal to a receiver in the TV gallery via aerials on the walls of the studio. (The radio mics do not work as well in Studio B as in Studio A.)

Setting Up

The batteries are fitted in the belt packs by opening the front panel. Squeeze the two buttons on the side of the unit and the panel will drop down.

Fit the batteries, observing the correct polarities.

Unlike in some battery-powered devices, the batteries both go in the same way round.

Switch on the belt pack by pressing and holding the ON/OFF button - inside the flap - for a couple of seconds until the screen lights up.

The screen shows the frequency the transmitter is using at the top, the battery strength at the bottom and the audio input from the mic at the left.

The red “LOW BATT” light is misleading: it flashes when the batteries are low…. when it is steady the batteries are fine!

The number – 1 in this case – shows it is radio mic No 1 in our set of six.

Each transmitter pack uses a different radio frequency which is matched by one of the receivers in the gallery. These should not be changed.

Fitting the Mic

In a lot of TV work it is acceptable to be able to see the clip mic but for drama it will need to be hidden beneath clothing. (See below.)

It should be the sound operator’s job to put the microphone on the presenter, guest or artist. They will probably have more experience and knowledge of how to fix the mic than its user and will be able to avoid some of the problems of using personal clip mics.

The tiny microphone capsule is omni-directional – it picks up sound with equal sensitivity from all directions. So in terms of sensitivity it doesn’t matter which way up it is fitted.

But the holes in the top of the capsule mean this end is more likely to pick up plosives when people are speaking. These are the pops and bangs from mouth noises or wind/breath hitting the capsule, and can sound awful.

Mounting the capsule so that it looks ‘upside down’ avoids these unwanted noises and because of the mic’s omni-directional sensitivity has little effect on the sound it picks up.

The capsule can be removed from the clip and mounted the other way up so that it can be clipped to either lapel or a shirt/blouse with left or right opening. Just loop the cable through the jaws of the clip, but don’t nip it or it can be damaged. In fact take care when handling the cable at any time – its small size makes it easy to damage.

The transmitter pack has a clip for attaching it to a belt or waistband. Or it can be put in a pocket.

DO NOT place it on the contributor’s chair or in their lap. When they stand up it will hit the floor which is obviously not good for it.

The cable should be loosely coiled up and hidden under clothing, in a pocket or tucked in the waistband. Allow for some movement so that the cable is not pulled tight at either end as the wearer moves about.

Click for further information on mic placement...

Microphone Etiquette

These mics are called personal for a reason – they are designed to be fitted close to a person’s body and this can cause difficulties and embarrassment when they are being fitted.

Ideally the cable needs to be hidden underneath clothing – another possible embarrassing factor when approaching a guest and asking if you can ‘mic them up’.

Do not attempt to pin a personal mic on someone without asking if you can, or telling them what you need to do.

Where to place the Mic - with this type of microphone we need to think of two things; position for best sound and how to get it there and fix it. The standard clip will work in most cases.

Best Sound

The mic should be about 10-15cm from a person’s mouth, and if it is not going to be central then you need to think which way the person will be facing during their appearance in your show. If they are being interviewed and the interviewer will be on their right, then their microphone should be on their right too. Obviously, the reverse applies if the interviewer is on their left. Similarly, if they are the presenter their mic should be on the side nearest their guests.

Do not put the mic under a person’s chin – you will get muffled sound.

Do not ‘hide’ it in a scarf (unless it is very lightweight) – muffled sound.

Avoid necklaces/jewellery – they can bang or scrape against the mic.

Placing the mic under a jumper or top can cause noises from rubbing.

How to Fit the Mic

The best approach is to assess from afar where the mic needs to go – on a lapel, under the shirt or blouse etc – and then explain to the contributor what you need to do to pin the mic where you want it.

People wearing jackets are easy – the mic is pinned to the lapel and the transmitter pack can often go in an inside jacket pocket. Just make sure to coil up the excess cable and put that in the pocket too.

People wearing only a shirt or blouse can be trickier. The easiest way is to take them away from everyone else in the studio and ask them to thread the mic and cable up their top and bring it out in the right place. You can then position the mic properly.

If an actor or actress needs a mic fitting under tight clothing this should all be done in the dressing room or green room – i.e. in a private setting – by someone the artist is happy to have help them.

If you need to completely hide the mic – perhaps for a drama – there are sticky patches available which can be used to stick the mic under clothing or even to the actor’s skin. But rustling from clothing is a big problem which can be more or less serious depending on the type of fabrics worn, how tight they are and the action required in the scene.

Warn the person wearing the mic that:

● they can be heard by other people at any time, so should be discrete

● they might forget they are wearing it

● to remove it before going to the loo

For additional information on mic placement, follow this link - Mic Placement

In the Gallery

The radio mics need receivers to pick up the radio signal and output the audio. In Studio A gallery, the six receivers are mounted to the left of the sound mixing desk.

They are switched on using the two switches underneath them.

They are numbered 1 to 6 and each receiver picks up the signal from the corresponding transmitter pack.

In the window you can see the matching radio frequency, if the transmitter is muted and its battery level.

It also shows:

The strength of the radio signal (RF)

and audio signal (AF).

If the panel is red, it means the transmitter pack is switched off.

The outputs of the radio receivers appear on the sound jackfield/patchbay. From there you can plug them to inputs on the Studer Vista sound desk.

IMPORTANT

The radio frequencies we use are governed by law. We are only allowed to use certain frequencies and so you must not change the frequencies on the radio mic transmitters.

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