Introduction
There are broadly two types of radio microphones available:
The handheld microphone houses transmitter, battery,
microphone and aerial in the same body. The lavalier
microphone can be "hidden" on the actor. |
Sennheiser
Evolution radio mic system. Handheld mic, transmitter pack
for lavalier mic and receiver. |
Lavalier
Microphone
The Lavalier radio microphone system consists of two main parts:
1) Transmitter
2) Receiver.
The transmitter
(containing a battery) is placed within the actors costume, and
has a microphone head (or capsule) and an aerial
connected to it. Many types of capsules are available, but the
industry standard is the Sennheiser MKE-2.
Placing
lavalier microphone capsules
Most
microphones are supplied with spring clips to attach the microphone
to the lapel, tie or other part of clothing. This is fine where
you are recording voice, or for TV/video. For sound reinforcement
(e.g. in a stage musical) the microphone must be much closer to
the mouth to get maximum gain (volume) out of the system. There
are broadly two positions that are used.
1)
Forehead / hairline / wigline
The
microphone is placed at the edge of the hairline on the forehead.
Surgical tape applied over the cable and body of the capsule can
be made up to match the skin tones surrounding it.
2)
Over the ear
This
position can be better for sound quality and can enable a better
"fixing" of the microphone onto the head. Earloop is
available from specialist suppliers (flesh-coloured florists wire)
which can be tied to the microphone cable just below the capsule.
This makes a fixing in the over-ear position much more secure.
The best place is around 2cm from the ear towards the mouth. Make-up
can be applied to tape used to secure the mic in place.
Boom
microphones
Some "pop" musicals use boom microphones which end up
near the mouth and are worn on a band around the back of the head.
These aren't suitable for all applications though.
Using
tape
The standard tape used on radio mics is surgical tape,
available from chemists. Sometimes there are problems
sticking this to some skin types, so you may need to try
more specialist surgical tapes (3M make "Dermablend")
which has better adhesion and takes make-up well.
Be sure not to get make-up onto the actual head of the
microphone. Scotchguard spray can sometimes be used to
waterproof the head of the microphone to reduce possible
sweat damage.
Setting
up and Using Radio MIcs
See
the excellent pages on MM Productions' website
http://www.mmproductions.co.uk/radio1.html
Radio
Signal
Two different radio frequency (RF) signal ranges are in use with
radio mics.
VHF (Very High Frequency) Cheaper, prone to signal dropout,
lower quality.
UHF (Ultra High Frequency) More expensive, higher quality
signal.
NB:
The above comments are not suitable for all applications and types
of microphone. Be sure to check with the supplier / owner of the
microphone before doing anything which may cause damage.
sound