The most common type of microphone found in live music settings is the dynamic microphone. In most dynamic microphones, a very thin, light, diaphragm moves in response to sound pressure. The diaphragm's motion causes a voice coil that is suspended in a magnetic field to move, generating a small electric current. They are generally less expensive than condenser microphones (although very high quality dynamics can be quite expensive),and dynamics feature quite robust construction and can often handle very high SPLs (Sound Pressure Levels).Arguably, the most popular brand of dynamic microphone for live use are the Shure SM58 vocal microphones and the SM57 instrument microphones. These are reasonably priced (£ 85 - £100) microphones that have the durability and sound quality to be used by large and small venues, from stages and lounges all the way up to the likes of the NEC arena, Birmingham. Dynamic microphones are very versatile and can be used on most instruments, for studio and live use, making them an all-round good type of microphone. The function of a dynamic microphone is to be durable enough to sustain a live performance and to project the audio that is gone through them out of the monitors and speakers on stage. This diagram below shows the source of sound, from the microphone to the monitors (XLR leads are red, monitor leads are blue):
Ccondenser
Condenser microphones are less commonly used in the live sound environment because of their more sensitive diaphragm and less resistance to high volumes. To mic up an instrument, amplifier or to be used for vocals, a dynamic microphone would be preferable, although it is down to personal preference of the musician and the technician. Condenser microphones require phantom power in order for them to work, which means that for a live situation you may need to enable phantom power on the desk, as well as an optional external backup supply such as a phantom power box. This just means more cables and hardware which is a lot more complicated than just running a dynamic microphone. A popular use for condenser microphones, both in the studio and live performances, is for overheads when miking up a drum kit. Overhead condenser microphones would be used for larger venues, however on a small stage where the drum kit volume is overpowering enough already, overheads will not be necessary. Condenser microphones are more sensitive than dynamics, so using condenser microphones such as the Samson CO2 pencil, or the Shure KSM44/SL will mean that a lot more background noise will be picked up, which is not good when in a live environment. As well as this, feedback will be a concern. As mentioned earlier, condenser microphones are much more sensitive than dynamics and will pick up a larger range of frequencies, meaning that monitor feedback will be much more common. Feedback from a microphone is something that a sound technician would want to avoid at all times, so using a condenser microphone would be strongly not recommended.
Lapel Microphones
Lapel microphones are small, wireless
ribbon microphones that clip onto the performers clothing, allowing for hands
free capability. There are run from the mixing desk into a receiver via an XLR
cable, and from the receiver it is picked up by a radio transmitter that is
connected to the actual microphone head, worn by the performer. Lapel
microphones have a high frequency response and are prone to feedback if
incorrectly positioned on stage (much like most microphones really) but from my
previous experiences, they feedback much easier than any dynamic microphone or
some condensers. Lapel microphones are only practical for live use because of
the one feature that separates them from any other type of microphone, the hands
free capability. It is very common that you see TV presenters, comedians, and
theatrical actors using them because they need there hands to perform and they
need to move around the stage. This diagram below shows how they are routed
through the desk:
The O2 arena, London, holds a large amount of live on stage microphones, however they popularly use AKG dynamic and condenser microphones. As mentioned in previous paragraphs, dynamic and condenser microphones have different purposes for live sound. The O2 arena use similar style microphones to any other venue, even at our school. AKG microphones serve very similar purposes to the shure dynamic microphones, as they are both very diverse, and very good quality. There is no mention of lapel microphones on the website, however they will definitely get used for a large pop/rock venue.
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