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It
is most important to select the right microphone
for the job. This will vary with the application – for example speech,
vocal, or instrumental – and type of meeting. Your choice of
microphone will also be influenced by the number of people present, the
extent to which they will be expected to participate, and the
size and acoustic nature of
the venue.
It
is always better to speak within 6-18" of the
microphone. It is, therefore, best to use either a clip-on or a
hand-held microphone. The
latter may be held or fixed to a table or floor stand.
To focus more clearly on the speaker, use a unidirectional
microphone. This will focus your speech and
reduce noise and reflections from around the room. Seminars
/ group activity
One
or two well-placed fixed microphones may suffice: for example, a single
boundary microphone for a small group of maybe six people at a round
table. Or an overhead, hyper-directional (rifle)
microphone may be focused on the group from a distance – but
the microphone position is critical and more than one microphone may be
necessary. How effective
this will be depends on room acoustics, the distance of group members
from the microphone(s) and
how well they speak up.
Multi-microphone
systems are ideal for group use - where practicable and affordable. They
require additional equipment to mix the signals from all the
microphones. Ferrosound have developed a single line, multi-microphone
system, which enables members of a
group to have their own clip-on microphone,
at relatively low cost. However,
it is often more affordable and simple to deploy one or two suitable
boundary microphones. Ferrosound
can custom-make very discrete wireless versions for free standing on
conference tables where trailing cables are not desirable. Reception,
registration, cross-counter & similar applications
Microphones
need to be carefully chosen and deployed
for this type of local loop system. Where possible, Ferrosound select
and place microphones so as to provide benefit for people on both sides
of the counter or reception/registration desk. We have also developed a
portable local loop system, which is superior to any similar portable
loop system on the market.
Wireless
microphones are widely used in churches, clubs, entertainment venues,
conference and lecture rooms.
They also provide a safe, option for use in homes and centres for
older people, where trailing microphone
leads may be hazardous. Wireless
microphones for use in these applications operate on two frequency bands
– VHF
and UHF.
In each band there are a number of frequencies available for
public use, for which no licence is required, provided the equipment is
type-approved. VHF wireless microphones are now very widely used in all these venues – so there is always the chance of interference between systems. This occurs when venues within range of one another (up to 100 metres) are using the same frequency channel. More expensive systems are multi-frequency, so it is a simple matter to select another frequency. The lower cost systems are pre-set to the frequency of your choice, so it is necessary to replace the whole system in order to change the frequency channel. The
more expensive, UHF wireless microphones are
generally better quality and less prone to interference.
The UHF band is also less crowded.
Moreover, even budget UHF systems are available with multiple
frequencies, so it is a simple operation to switch from one channel to
another, when necessary. A
Wireless microphone system comprises
an ordinary microphone (any type), a transmitter and a receiver.
Each system requires its own radio
frequency, or channel, in the same way that broadcast radio &
TV does. The transmitter
may
be built into a hand-held microphone, as an integral unit, or into a
small case, which may be clipped to a belt or placed in a pocket.
In the latter case, a
separate microphone
is
plugged into the transmitter.
This microphone may be
clipped to clothing or built into a headset. Transmitter packs require a
good quality alkaline battery, usually 9v PP3. Battery life is typically
10-12 hours. The
wireless
receiver
is usually housed in a case, which is free standing or rack-mounted, and
requires dc power from a small mains power supply unit.
Receivers may also be very compact, battery-powered, pocket-sized
units for mobile use. In
this field, there are two types of wireless microphone system, the
diversity and the non-diversity type.
The diversity
system
employs two aerials and is more reliable in larger venues. It also
reduces interference between radio signals when more than one radio
microphone is in use The less sophisticated non-diversity
receiver costs less and may be fine in smaller venues, or where only one
system is in use. Ferrosound
can source and supply any wireless microphone system on the market. This
enables us to provide a truly custom service, tailored to our
Customer’s application and budget.
The best guide to price is to spend as much as you can afford! Budget
range microphones supplied will be good quality, reliable products.
However, they may not include useful features available on higher
priced microphones. For
example, it is very useful to have low
battery indicator,
which is generally only available on more
sophisticated microphones. It is also useful to have multi-channel
systems,
so channels can easily be switched to avoid interference from other
users, should that occur. Multi-channel
systems also allow more flexibility in the use of the actual microphone
(transmitter). And, of course, it is important to consider sound
quality –
especially with hearing loop systems, where the user
requires the best quality possible. The more
sophisticated systems provide more useful features and
higher sound quality – but they cost significantly more.
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