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.
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.
• 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
• 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
• 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.