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HELP CHOOSING MICROPHONES
Selecting a vocal microphone can be a
tricky task if you are unfamiliar with such things and even if you are
seasoned performer, a lot comes down to a matter of personal preference as
well as the purpose for which it is being used for. We have produced a
short guide to assist you chose the right microphone.
On the relevant
pages we have also supplied a brief listing of which microphones we offer
are most suitable for specific applications. Of course, as well as
suitability there is also an issue of quality, and that is most commonly
reflected by the higher the price, the better the microphone. We are
always happy to advise as to the most appropriate type for your particular
circumstances.
Microphone Types
There are two main types of microphone – Condenser and Dynamic.
• Condenser
microphones
Condenser microphones tend to have a
broader frequency range and are more accurate in producing sounds at the
top of the spectrum. This very clinical and accurate sound is often
favoured by experienced vocalists, particularly those performing jazz,
blues, folk and less amplified music. They are, however, less robust and
require a phantom power supply to make them work, so they will always need
to be plugged into a mixing desk supplying this power – they can’t be
directly connected to a pair of powered speakers. Condensers commonly come
in two variants – Large Diaphragm which due to their size and extra
sensitivity are chiefly used in a studio environment but do have their
place on quieter stages when classical instruments or an acoustic guitar
needs to be picked up or the vocalist has a soft style of singing; and
Small Diaphragm which are the more common type found on stages and are
suitable for handholding.
• Dynamic microphones
Dynamic microphones offer a narrower
frequency range, which isn’t always the disadvantage that it may seem to
be on the face of it. They tend to sound warmer and richer and are more
forgiving with less experienced vocalists. In most cases they suit louder
vocalists better, and are excellent on noisy stages as their feedback
rejection is higher. They also suit ad hoc speechmaking very well, as the
technique to use the microphone effectively is much less demanding. They
are also very resistant to knocks and need no phantom power supply so can
be plugged directly into a speaker.
Condenser microphone
Dynamic microphone
Polar
Patterns
As well as the type of microphone, you also need to consider the Polar or
pick-up pattern of the microphone. This relates to the direction from
where the sound is picked up. Again they come in various types but the
main variants that concern us here are:
 • Omni or omnidirectional, which have
an even pattern all around the microphone, front back and sides. Omni
microphones are useful in situations where you are trying to mic a small
group of people with one mic (such as a public meeting) but it isn’t
located near to the PA, as the wide pickup pattern makes them more prone
to feedback, or when using a lavalier (lapel) microphone for general
speech so the positioning of the microphone isn’t critical.
 • Cardiod, which
picks up to the front and side but only receives sound from very slightly
behind the mic head. These are the best all round solution for
speechmaking from the hand or for vocals as a solo performer or in a band,
where the stage is less heavily amplified with backline and is positioned
well behind the PA system. They are easy to use for less experienced
performers as they pick up within a good range of the microphone capsule
 • Supercardiod and
Hypercardiod mics reject more noise from the
sides and pick up most effectively from head-on. A small quirk here is
that although there is nothing behind the plane of the capsule to the
sides, there is a tail directly behind the head. This is wider and
longer on a Hypercardiod, and shorter and narrower on a Supercardiod.
These mics tend to be preferred on a noisy stage to aid feedback
rejection, but do require disciplined head-on microphone technique and
therefore are more commonly used by experienced performers. Care also
needs to be taken with positioning of stage monitoring as their tail can
cause feedback. For this reason, monitors are commonly angled to the
performer so they are in the “dead area” of the microphone pick up, either
as singles or in pairs
Wireless Microphone Transmission Types
Whilst all the above is relevant with
regards to the actual microphone there is a further element to consider
when looking at Wireless microphones – the transmission band within which
they work.
Today there are three frequency bands which are most
commonly used: analogue on VHF and UHF and digital on 2.4MHz Wi-Fi:
• VHF
microphones are allowed to operate on only a very narrow frequency band
(between 173.7 and 175.1MHz) which as a consequence is pretty crowded with
traffic and can suffer from overspill from other local shortwave traffic
such as marine, taxi and CB radios. Systems used fixed frequencies and if
by chance that coincides with another user nearby on the same wavelength
you may receive interference. In addition, the narrow band makes it
unsuitable for the use of multiple microphone systems. Reception distance
also tends to be much shorter than with other frequencies. Despite these
downsides, if used in a quiet location without much radio traffic, these
are still a workable and cost effective choice.
 • The UHF
band is where most systems nowadays reside, from entry level all the way
up to professional and broadcast standard. As UHF also tallies with modern
Digital TV frequencies the UK Government have set aside two channels (38 and
70) to enable wireless microphone use. Only the relatively narrow channel
70 (863-865MHz) is available free to air whilst a license is required for
the use of Channel 38 (606-613.15MHz). We can supply systems in both
Channel 38 and 70 and Channel 38 systems come with the licensing fee
already covered by us. Other frequencies are occasionally licensed for
special events (festivals, major sporting events, etc.) dependent upon
gaps in the spectrum in that locality upon application to the Government
agency Arqiva.
UHF systems have the benefit of a longer range of
transmission and on Channel 38 a much wider range of frequencies over
which to broadcast, allowing for the use of multiple microphones at the
same time. Usually, systems’ frequencies can also be adjusted to avoid
interference. Channel 38 tends to be used only on higher end equipment
which is more expensive as a result. However the chance of interference is
relatively small. Channel 70 systems are available at all areas of the
budget but as they are on a free to air frequency which is both much narrower
and more crowded, as a consequence they are more prone to interference and
slightly less reliable. If your wireless microphone use is critical then
it is safer to opt for a higher end Channel 38 system, unless you are in
lightly populated area.
 • Wi-Fi Band
– Recently there has been a trend to move to use the 2.4GHz Wi-Fi band as
this is completely outside traditional RF frequencies. It also has the
benefit of being free to air. Because these systems are digital rather
than analogue, they use much less bandwidth to transmit the same
information, assuring of very high quality sound without companding
(compression and then expansion) that is required to broadcast on VHF and
UHF bands (although some premium UHF systems can sound as good as Wi-Fi due to advanced companding
algorithms).Range also tends to be good and multiple systems can be used
together. They are also very simple to use with frequencies being set by
simply selecting a matching number on the transmitter and receiver or even
allocated themselves automatically by the system using the best available
frequencies. There are, however, some downsides to Wi-Fi. Systems can be
prone to interference from modern local RF traffic such as Wi-Fi routers,
mobile phones, laptops and tablets. When the digital signal is interrupted
it can result in “drop-outs” – breaks in the signal creating a stuttering
effect. Modern systems have introduced many devices and fail safes to
counteract this problem, but if the signal is critical it is advisable to
also hire directional external antennae (which we can supply) and make
sure that the transmitters (handheld microphones or belt packs) are in an
uninterrupted line of sight to the receiver.
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