So, your new musical project it’s almost ready, and it’s time to add your voice to it. To choose the best microphone for this, you will have to learn how to navigate hundreds of models. To do this, you need to learn what microphones are, and what characteristics to pay attention to. As soon as you form such pieces of knowledge, you will begin to understand what to buy for your task. There are three main types of microphones used for voice recording: dynamic, condenser, and ribbon.
It is based on a construction of a diaphragm connected to a metal coil inside a magnetic field. Sound waves cause the diaphragm to vibrate, which acts on a coil that generates an electrical signal. Such microphones withstand high sound pressure levels, are less sensitive than other types, and are more resistant to mechanical damage.
They are typically used to record loud sources of sound or strong voices and are more commonly seen in live concerts. Dynamic microphones are versatile, inexpensive, and easy to use, they don’t need phatom power. And to increase the volume level, you can use special compact preamps.
Thanks to its high sensitivity and wide dynamic range, it is the most used recording tool in the studio. It captures the subtle nuances of the recorded audio signal. Inside the case is a thin movable diaphragm, which is located close to the fixed plate. The plate and diaphragm are connected to a power source. This creates a charge between them. When the membrane vibrates from sound vibrations, the distance from it to the plate changes.
So an electrical signal appears, which then needs to be further amplified. As a rule, condenser microphones are made on a valve or transistor circuit and are equipped with active electronics, so they require phantom power (usually +48 V). The size of the diaphragm also varies: a condenser microphone can be with a large, medium, and small diaphragm.
Large-diaphragm microphones (greater than 3/4”) are larger in size. These microphones are suitable for any studio recording. Microphones with a small diaphragm (less than 5/8″) have the highest sensitivity, especially in the upper range, and are mainly used for recording instruments such as acoustic guitars or cymbals. Medium diaphragm microphones (5/8″ to 3/4″) are a compromise solution.
On the one hand, they are also quite sensitive to high frequencies, on the other hand, they give a warm and rich sound, almost like microphones with a large diaphragm.
Used in the studio recording of vocals and instruments, they have a very warm and natural sound. Ribbon microphones work in a similar way to dynamic ones, but instead of a diaphragm, a thin metal ribbon is installed, located in a magnetic field.
The vibrations of the tape from sound waves create an electric current. The design of such microphones is very fragile, and they can be damaged even by strong airflow. Therefore, such microphones are not suitable for field recording or drum track, but they will be able to convey the subtle nuances of the voice and give it a specific vintage color.
Separately, it is customary to single out two more types of microphones: USB and wireless microphones. USB microphones – with the exception of dynamic models like the RODE Podcaster and Shure MV7, these are condenser microphones with a built-in preamp and analog-to-digital converter.
USB microphones connect to a computer or mobile device and record sound without additional hardware. This is convenient and inexpensive, but you need to be prepared for the fact that the built-in amplifier and digital-to-analog converter will be the cheapest. And if such a microphone fulfills the task of recording a podcast or stream, then the device will not be enough for a high-quality studio recording of a professional vocalist.
Wireless microphones or radio systems are a concert solution. The system consists of a microphone with a built-in transmitter and a separate receiver station that receives a wireless signal and transmits it through a wire to the mixer and speakers. The design is needed in order to allow free movement around the stage.
Microphone Pickup Pattern
A pickup pattern is a pattern within which sound is picked up by a microphone. This is one of the main characteristics because it depends on it what possible options for the location of the instrument during recording.
There are three types of microphones based on their directivity: Unidirectional (cardioid, hypercardioid, and supercardioid), Bidirectional, and Omnidirectional (cardioid) microphones that are the most common in studio work. Their front-focusing (heart-shaped) directivity allows you to record sounds in front of the microphone, cutting off unwanted ambient noise.
They are often used in live performances, recording studios, and home studios. Supercardioid microphones have a narrower front signal recording area than cardioid, as well as a small sensitive area on the back. Hypercardioid – microphones with a narrower directivity than supercardioid and a large zone of sensitivity on the opposite side.
A special case of a hypercardioid microphone is a shotgun mic or gun microphone. Directionality is still narrower here, and such a microphone is needed for specific tasks: for example, on filming or when recording a choir. Narrow directivity allows you to cut off unnecessary ambient noise and place the microphone far enough so that the recorded signal does not suffer from the proximity effect.
Bi-directional microphones can record sound from both sides. This orientation is suitable for recording two sources at the same time, such as a duet of vocalists or two instruments. This pickup pattern is not as popular as the others, usually found in ribbon mics, large diaphragm mics, or switchable directional mics.
Omnidirectional microphones (omni) pick up sound from all directions equally. This option is suitable for recording in rooms with very good acoustics, where the sound of the room is as important as the main signal being recorded. But the background noise and feedback cannot be cut off here.
Microphone Sensitivity is expressed in terms of the sound pressure exerted on the diaphragm of the microphone. The measurement uses a standard tone at 1 kHz with a sound pressure level of 94 dB SPL (1 Pascal). The output signal is measured in either mV (millivolts) or dBV (decibels relative to 1 V). The higher this mV value, the higher the sensitivity of the microphone. But in dB, the sensitivity characteristic is a negative number, which means that a microphone with a sensitivity rating of -40 dB is more sensitive than -55 dB, and -55 dB is more sensitive than -60 dB.
Condenser microphones are usually more sensitive than dynamic microphones. Microphones with high sensitivity are needed to record a signal with a low sound pressure level, for example, when recording a voiceover or recording a vocal part.
Microphones with low sensitivity are suitable for recording guitar cabinets, drums, or loud vocals. Frequency response The frequency response of a microphone determines the range of sound that the microphone reproduces and how the output changes over that range.
It is indicated in the form of a diagram, where the frequency range and the balance of these frequencies. For example, if we need to smooth out overly sonorous vocals, then we can choose a microphone with a less pronounced treble response. Or vice versa, a microphone with higher frequencies in the upper register will help to make the voice brighter.
Power Supply Microphones with active circuits, such as condenser circuits, require phantom power. Phantom power is a positive voltage of 12 to 48 volts DC, which is applied to the second and third pins of the XLR cable that connects the microphone. Most audio interfaces, mic preamps, and studio mixing consoles have phantom power. If this feature is not available, you can purchase a separate phantom power supply or preamplifier with +48V supply. Dynamic microphones do not require power.
This indicates the background signal that the microphone itself produces, even if the sound source is silent. Self-noise is measured in dB-A (A-weighting is a method of simulating human perception). More budget microphones tend to have higher noise levels.
This characteristic is important because the noisier the microphone, the more limited you are in how to position it. It will have to be placed as close to the signal source as possible so that the signal is not distorted by background noise. Remember that noise can come not only from the microphone itself, but also from other equipment: a preamplifier, an audio interface, and even a cable.
SPL and dynamic range SPL is the level at which the total harmonic distortion (THD) does not exceed a given value, that is, the volume that a microphone can pick up without noticeable distortion. Typically, the harmonic distortion threshold is 0.5%, but some manufacturers measure it at 1%, which increases the maximum SPL. The dynamic range of a microphone is the range between the quietest and loudest levels it can record.
The dynamic range of a microphone is largely related to its sensitivity. Associated with dynamic range is the headroom parameter. This is the term for the headroom of the signal, which allows you to exceed the nominal and transmit a signal without distortion.
If you had the patience to read this article, I am sure that now you know a lot more about the types of microphones available in the market, what they are good for and which is the best microphone for you.