Microphones are acoustic-to-electric transducers that convert one form of signal/energy into another. In this case they convert sound/air pressure/mechanical vibration (our voice) into electrical signal and send it down the microphone wire. This level of signal is termed as “Microphone Level” or simply "Mic Level" signal and it happens to be very low. It can also be referred to as Sensitivity (in a non technical sense). Higher the sensitivity, higher the output.
Speakers do exactly the opposite. They convert electrical signal/energy coming from amplifier into mechanical energy by moving parts of speaker that in turn creates air pressure/waves. These waves of air pressure is what we perceive as sound.
Some general rules about microphones …
Pick a microphone that suits your voice the best – according to you. Our recommendations will suit most people in general. It is impossible to find a microphone that fits everyone equally. But you can find one that suites your Imam’s voice the best. Visit your local SamAsh store and test out the various microphones and pick one that you feel sounds best. Remember the general rule, there is no best microphone and there is no best sound. It is all about perception. If someone claims that he has found the best mic, do only one thing, run from him immediately. Some microphones are generally considered better than others and the ones listed here are based on years of testing various microphones for fidelity, clarity, feedback resistance and loudness.
Place the microphone in such a way which gives you the best sound. Speaking slightly over, under the microphone, across the microphone are all good techniques in salaat. This will avoid breadth sounds and popping. Keep microphone as close to mouth as possible but avoid sibilance (the ess sound) at the same time. Microphone position should also be in reference to the room acoustics. Even reflections from microphone stand and mihraab can effect sound considerably. With some experimentation you can find your sweet spot.
If you get too close to a microphone it tends to get boomy / muddy / bassy / sibilant. The low frequencies in your voice get hyped up which is not good. The phenomenon of how the sound changes with change in distance to source of sound (mouth) is called Proximity Effect. Pick a microphone that has least proximity effect within the unidirectional microphones category.
Pick a microphone that is balanced indicated by XLR connector at the back. There are other things you can also consider when buying a microphone like self noise, handling noise etc. Since most major manufactures have solved these problems, we are not going to discuss them here. Another thing, use a Vocal Microphone and not an instrument microphone.
Use slip on pop filters to avoid popping when certain words (or letters) are pronounced. Example “Rabbukum” will generate a pop without a good grill or filter.
Transient Response: A microphones ability to respond to rapidly changing sound wave. A sports car (condenser mic) responds to traffic changes much quicker than a 18 wheeler (dynamic mic). Pick a microphone that has good transient response.
There are various kinds of microphones in use depending on type of application, their durability, sonic signature, response type, polar patterns, design etc. We will discuss all these here and we will recommend what is most appropriate for Masajid. Remember one thing, it is all about the capsule inside the microphone that specifies what type of microphone it is. When we say it is a dynamic, cardioid mic, we are actually talking about the capsule inside the microphone. Wireless microphones will be explained separately as they involve things like RF Interference, Squelch settings etc., which need detailed explanation.
Also please refer to comb filter effect, phase and gain before feedback topics in the introduction section.