Recommended microphones for streaming / podcast / youtube

Guide to choosing the best microphone to record voice in studio, for example for live streaming, podcast or for youtube channels.

What do I need to record sound in the studio?

When we speak of ‘study’ we refer to a controlled environment: a room in which we have all the equipment we need, we have power from the electrical network, there is no wind, the external ambient sound is more or less isolated.

In studio what we are looking for is to optimize sound quality.

That is, on the one hand we want to achieve the highest possible fidelity : capture all the nuances and achieve a very clean final sound.

And on the other hand we want the final sound to be as pleasant as possible for our audience.

We will focus mainly on the voice . The same would be applicable if we want to record instruments, although there we would already go into specific questions about each instrument.

As we are going to see, the main element is the microphone, but keep in mind that there are other very important factors that we will see throughout this article.

We will also see what criteria we can follow to choose the microphone that best suits our needs.

Before starting to choose a microphone, we are going to give some hints of what we understand by sound quality and what differences there are between a good microphone and a bad one.

Signal and noise

What do we understand by quality sound or sound quality?

Imagine two people talking in a quiet room. The voice, the sound of one of the people speaking, reaches the ear of the other perfectly. He perfectly understands what he says. You can even set the tone, the nuances …

We would say that this sound has a very good quality.

Now we are going to suppose that we open a window that overlooks the traffic or we are in a room in which the neighbor can be heard shouting or we are in a cafeteria at rush hour … The voice no longer arrives with the same quality, or at least it is affected by other sounds that can distract us or even make us not understand some words or that we have to speak louder to make ourselves understood.

The information, the signal, is the voice of the other person. Noise is everything else, which in some way interferes or prevents us from hearing and understanding clearly.

This signal to noise ratio (SNR) is a very important quality parameter .

There are many sources of noise.

In this example we have seen a direct communication channel in which only sound intervenes.

But in other cases we will have a much more complex channel in which the sound (voice of person A) is converted into an analog electrical signal (voltages), then into a digital signal (numbers), it is processed in different ways, it is transmitted over long distances, it is reprocessed on the receiving equipment, converted to an analog signal again, and transformed into sound that person B.

In this second example we use a representation of the original sound. That representation is known as an audio signal or simply audio.

The degree of fidelity of that sound representation is another important quality parameter.

In the audio world, when it comes to fidelity, it is often referred to as the ‘color’ of the sound.

The color of sound

We start with the first element that represents the representation of a sound: the microphone.

An ideal microphone would be one that picks up sound with perfect fidelity: all the nuances, all the details, etc.

Basically the quality of a microphone is related to its sensitivity (ability to pick up low intensity sounds) and its frequency response (ability to equally pick up all frequencies of the human audible spectrum, from 20Hz to 20KHz)

But there are also other more subtle factors that have to do with the physical construction of the microphone: moving parts, inertia, resonances, etc.

No microphone works as an ideal microphone .

Every microphone, regardless of range or price, leaves a mark on the sound it picks up.

One microphone is said to be more transparent than another when its frequency response is flatter and leaves a more subtle imprint on the sound.

The imprint left by each microphone is often known as color . Each microphone gives a certain color to the sound it picks up.

And the color is also not something static: it depends on factors such as the distance at which the microphone is from the sound source, orientation, etc.

Assuming optimal placement (sweet spot), a microphone is considered good if it is very transparent (very faithful to the original sound) or if it adds a pleasant color to the sound it picks up.

A bad microphone is one that does not pick up sound well , distorts it, or adds an unpleasant color to most of the sounds it picks up.

For each instrument, type of voice or musical style there is a microphone model or a combination of them that best fits and gives it that special color.

For each situation there is a type of microphone that is optimal due to its physical characteristics: polar pattern, sensitivity, tolerance to loud sounds.

Starting from a certain level of build quality and technical characteristics, all the microphones are very good.

The difference between models and ranges would be in those nuances of color and in the specialization.

Some of the positive and negative characteristics of a microphone can be reinforced or corrected by editing the sound, using filters, equalization, etc.

But there are more subtle features that have to do with the physical construction of each mic and are very difficult to correct or emulate in post production.

Some of these characteristics have to do with the principle of operation.

The most widely used microphones are dynamic and condenser microphones .

Dynamic microphones

The sound-collecting membrane is attached to a coil wound around a magnet.

The movement of the membrane in response to sound generates an electrical signal by induction.

The principle is exactly the same as that of a loudspeaker. In fact, a speaker can function as a microphone and a dynamic microphone can function as a speaker.

Advantage:

• They do not need external power, they work as is: without batteries or batteries
• Withstand very high sound levels
• They isolate the sound from the environment very well
• They are very resistant to shocks
• They have a good behavior for the human voice

Disadvantages:

• They do not have much sensitivity
  This is bad for certain applications and good for others, for example it is good to better isolate the main sound source from the environment
• The coil has some inertia and does not respond well to high frequency sounds (the sound is said to lose brightness)
  But the human voice has most of the information in the mid frequencies.
• As their sensitivity is lower, they need more amplification to reach the
  correct signal level. Dynamic microphones need preamps with some gain, with a good amplification margin.
  In some cases they need a specialized preamplifier: fethead / cloudlifter, which would go as the first stage, before the preamplifier of the audio interface, mixing console, etc.

Dynamic microphones are widely used in concerts and situations where you want to isolate, for example, the voice of the singer or the person speaking from other nearby sound sources.

They tend to give a warm nuance, emphasize more the bass and especially the mids, while attenuating the treble (higher frequencies).

Condenser microphones

They have an element, the capsule, which is basically a condenser: two metal plates separated by an elastic element.

The front plate is the diaphragm. The sound makes the diaphragm vibrate and the separation between the capacitor plates is modified, which causes the voltage to vary, generating the electrical signal.

Advantage:

• Very high sensitivity
• Its frequency response is usually very good (very flat)
• They have good behavior for the voice and for a very wide range of instruments
• Since they have higher sensitivity, they don’t need a preamp with such a large gain range.

Disadvantages:

• They need an external power supply to polarize the capacitor and the associated electronics.
  The electret-type ones are built with a factory polarized capacitor, but they need power anyway because they include internally electronics that are responsible for impedance matching.
• They are very delicate to blows
• They are very delicate with very loud sounds. Too loud a sound can damage the microphone.
• They are very very sensitive.
  This, which in principle is an advantage, is also a disadvantage depending on the situation, because they tend to pick up any ambient sound no matter how small.

The main characteristic would be its sensitivity and its frequency response.

They are the ones that are closest to what we might consider an ‘ideal microphone’ from a fidelity point of view.

A good condenser microphone can capture even the smallest detail of a voice or an instrument, all its nuances.

This is good and bad at the same time.

For example, if we are in an environment isolated from external sounds, that is, in an acoustically conditioned studio: we are going to get the best out of an instrument.

But if we are in an environment with other sound sources, it is very possible that all those parasitic sounds will slip through.

Also in the case of the voice, sometimes they are so sensitive that they collect all the small sounds that we make with our mouth while we speak and that can become distracting or even annoying.

Large membrane or small membrane

Large diaphragm condenser microphones tend to sound warmer, said to be more natural or more organic for the voice.

As the membrane is larger, it has a bit more inertia, and the high frequencies are attenuated or lost a bit.

A bit of brightness is lost but a bit is gained in the bass (warmer, darker sound)

Small diaphragm microphones would be the most transparent , in the sense that they pick up the entire frequency range very well.

The color they provide is more subtle and depends on each specific brand and model.

Directionality (sound pickup patterns)

This characteristic applies to all microphones and tells us what the sensitivity of the microphone is depending on the direction from which the sound arrives.

• Omnidirectional
  They collect sound equally in the entire sphere around them.
  They are ideal for example to pick up ambient sound
• Cardioids
  are more sensitive in one direction, a hemisphere really.
  That is, if they are pointing in one direction, all the sound that comes from behind or from the sides will be very attenuated.
  They are said to ‘reject’ sound coming from those directions
• Supercardioid, hypercardioid …
  Different versions of directional microphones, with narrower pickup angles.
  They are typical patterns of shotgun microphones.
• Bidirectional
  Basically they would be like two cardioids united in a single microphone.
  They pick up sound from the front and rear, and attenuate sounds from the side.

Preamplifiers

The electrical signal generated by a microphone is very very very small …

It is of the order of millivolts (mV)

The electronics that process the audio need to work with signals of the order of the volt (about 3 orders of magnitude higher).

It is essential to increase the signal coming from the microphone.

The microphones connect to a preamplifier. The amplification level is called the gain (it would be like the multiplication factor, but in the audio world the logarithmic scale is used in decibels: dB)

It would be, let’s say, the first stage of audio processing and it is one of the most important because at the input the signal is so small that any electronic noise or electromagnetic interference will have a comparable level.

All microphones need a preamp.

In some the preamplifier is a separate element, for example preamps that include a sound interface or a mixing console or an audio recorder.

In other cases the preamplifier and all the additional electronics are included in the microphone body itself: for example in USB microphones.

Noise sources

When we have talked about dynamic and condenser microphones we have seen characteristics such as sensitivity, frequency response and ‘color’. All these characteristics would be related rather to fidelity .

Now let’s look at the signal-to-noise ratio part , which is the other important leg of sound quality.

We are going to suppose that the microphone captures a signal very faithful to the sound it receives and we are going to focus on the sources of noise that we can find.

Ambient noise

When we talk about studio recording I think it would be the most important and the most ‘damaging’.

The ambient noise can be the neighbor yelling, the siren of a police car or ambulance, that of the motorcycle, a barking dog …

It can also be the sound of the refrigerator, air conditioning, computer fans …

The ‘pop’ generated by the microphone.

Shock and mechanical vibrations picked up by the microphone.

They are sounds that do not add anything to the ‘information’ that we want to transmit. In some cases they are distracting and in other cases they can become very annoying, such as pops or knocks on the microphone … or the neighbor calling her child for snack.

How to avoid or minimize this type of noise:

• Try to record in an environment as quiet as possible, with closed windows, at certain times of greater quiet if possible …
• Placing the microphone close to the sound source to increase the signal-to-noise ratio
  This is the rule of thumb when using microphones.
• Take advantage of the microphone’s polar pattern in such a way that noise sources are oriented towards the less sensitive part of the microphone (usually the back of microphones with a cardioid, super-cardioid polar pattern, etc.
• More sensitive microphones will pick up more ambient sound as well.
  In environments with some ambient noise, dynamic microphones tend to be more effective at ‘rejecting’ such noise.
• Using pop filters or practicing to get good technique when speaking into a microphone
• Avoid hitting the microphone or its support, cable, etc.
• Attempting to mechanically isolate the microphone from the table (eg by using a mic stand on the floor or by mounting the microphone in an anti-vibration system)

Room reverb / acoustics

Reverberation is echo that occurs inside a room.

Sound waves bounce off rigid surfaces: walls, ceiling, floor… These rigid surfaces are mirrors for sound waves.

The microphone will receive the main wave that comes from the sound source (our voice for example) and also a whole series of reflected waves that arrive with a certain delay (phase shift) and amplitude.

When these bounced waves arrive with great amplitude (especially in the primary reflections), interference patterns are generated with the main wave. Certain frequencies are amplified, in others the waves cancel each other or are attenuated …

The result is equivalent to filtering or equalizing the sound : a distortion that we perceive as ‘canned’ sound, boxed in or as if we were speaking from a well.

If those secondary waves arrive very attenuated or do not arrive with very marked lags, then we have a ‘natural’ reverb that is usually pleasant.

One part of a room’s acoustics depends on its shape and dimensions: resonant modes. They tend to affect mainly low frequencies.

Another part has to do with the fact that there are parallel surfaces (walls to each other, ceiling and floor). Parallel surfaces generate what is known as floating echo: some waves can be reflected many times on these parallel surfaces, hardly losing intensity, until they reach the microphone with a fairly large phase shift and appreciable intensity.

And another part has to do with direct reflections on walls, ceiling, etc. (primary, secondary reflections, etc.) and has to do with the geometry of the position and orientation of the sound source and the microphone.

If we start from a normal room like the one we can have in a house or an office (which has not been designed and built as a recording studio), acoustic conditioning is not something trivial.

Main recommendation: do not spend money buying panels, foams and exotic elements for acoustic treatment. It won’t work for you. You may change the acoustics slightly, but if the starting acoustics were bad it will likely still be bad. If you want to do a serious acoustic conditioning, ask a specialized company for a quote.

What can I do if the acoustics in my room are bad?

The worst case scenario is usually: recording in a small, very square (symmetrical) room, with bare walls, with the microphone located in the geometric center and with the sound source far removed from the microphone.

We will try our best to improve that scenario:

• Rule of thumb: place the microphone very close to the sound source We
  maximize the signal ratio (voice for example) to noise (sound waves reflected by the room)
• Choose a microphone with a directional pattern (cardioid for example)
  This eliminates or attenuates a good part of the reflected waves
• A dynamic microphone is less sensitive and generally works better in this environment.
  Dynamic microphones ‘reject’ those reflected sounds more if we apply the golden rule: with the microphone close to the sound source.
• A small room (such as a bathroom or a small kitchen) will surely give us more problems than a large room
• Avoid bare walls
  An empty room will likely have very poor acoustics.
  In a normal room with furniture, decoration, curtains, paintings… all these elements help to reduce the ‘destructive’ reverberation.
  Shelves with books work very well because they generate a random diffusion, at least in medium and high frequencies.
• With the low frequency resonant modes we cannot do much, but if we notice that the sound has a problem in the bass we can try different positions of the microphone. Sometimes moving the microphone an inch can make a perceptible change because we had it right at one of the resonant nodes. Shotgun type microphones are often more prone to these types of problems. Bass traps can work, but it can also happen that you spend money on items that don’t solve your specific problem in the end.

Don’t get obsessed with this.

If you are going to record spoken voice, for your podcast or for your video, or you are going to broadcast live: the main objective is that the voice sounds good and that it is understood well.

Nothing happens because there is some natural reverb, in fact a voice without reverb would give a ‘dead room’ feeling.

Noise in the audio signal

We have already commented that the electrical signal generated by a microphone is very small.

In these early stages it is very easy for electrical noise to reach levels similar to that of the audio signal.

What kind of noise can be added to the signal?

• The microphone itself generates a level of electrical noise
• The cable that connects the microphone to the preamplifier works like an antenna: it picks up an electromagnetic signal from the environment and converts it into an electrical signal.
• The connectors, if they do not make good electrical contact with each other, act as noise generators (micro discharges -micro sparks- that translate into electrical noise)
• The power supplies of the equipment, if they are not well isolated, introduce noise (the typical humm at the frequency of the electrical network and its harmonics)
• The preamplifier and the electronics that handle these small signals introduce noise, for example thermal noise.
• If the amplification of the signal is not completely linear (proportional regardless of the input amplitude), distortion occurs. This would rather enter the fidelity part, but hey, we can also consider it noise.
• Converting the signal from analog to digital introduces a small error, which is also known as conversion noise.

Once we have the digital audio signal, all subsequent processes work with numbers.

It is the advantage of working in digital. No more noise is added to what was already there initially.

What can we do to avoid or reduce electrical noise?

• Choosing a microphone of a certain quality
  Especially in condenser microphones you can notice a big difference between a poor quality one and an acceptable one
• Use shielded cables to connect the microphone and, if possible, balanced cables (systems)
  If the system is not balanced, try to avoid using very long cables
• The XLR connectors and connectors 1/4 offer greater contact surface
  connectors 3.5mm often give more trouble
• The quality of the preamplifier is important
  For example preamplifiers integrated computers are usually pretty bad
  A typical interface audio input current range usually include very good preamps

Recommended microphones for voice recording

As we have discussed, our goal is to record voice in the best possible quality within a reasonable budget.

The cut-off price for this type of microphones would be around 100 euros (from 80 to 150 to put a margin that includes more variety).

Below that order of magnitude, it is difficult to find microphones that offer reasonable quality.

Above, of course, we will find very good microphones, but the difference in quality will be more subtle and will probably only be noticed using studio monitors (calibrated speakers) or headphones of a certain range.

Any of the microphones we are going to recommend offers more than enough audio quality for most projects.

Remember that you can also use lavalier microphones in the studio, even for direct, streaming, etc.

But in general, a studio microphone will give you a higher level of quality.

XLR microphone or USB microphone?

If you want something practical and uncomplicated, choose a USB microphone of a certain quality .

If you want to go a little further, I recommend an XLR microphone with a sound interface.

With an XLR microphone you enter the world of the professional sound range, even with a basic equipment: connectors, cables, signal levels, way of working …

You have more control over all stages and can learn much more about sound and its treatment.

In addition, the sound interface helps you integrate audio from other sources: guitar, keyboards …

Conventional microphones (XLR)

With XLR microphones we also need a sound interface that takes care of:

• Power the microphone if it is a condenser microphone (48V phantom power)
• Includes balanced XLR connections to minimize interference from cables
• Includes different preamplification stages depending on the input signal (microphone, line, high impedance …)
• All keypad, dials and channel management electronics
• Analog to digital converter (ADC)
• Additional sound signal management functions depending on the make and model
• Electronics to encode and send the digital signal through the USB bus to the computer

Although it may seem very cumbersome and complex, the truth is that the connection and use of a sound interface is very simple, at least the basic use that we will normally do in our voice recordings.

Advantage

• Much more flexibility
• In general, better sound quality (it will depend on each specific model) compared to a USB microphone
• We have more control of the analog signal before passing it to the computer
• We can use different microphones depending on the situation and we can use several microphones at the same time if our interface has several input channels.
• These microphones can be used everywhere, we only need a portable recorder with XLR connectors
• You can test and expand your equipment in a modular way: microphones, interface, mixing console …

Disadvantages

• Initial investment may be a bit higher (compared to USB)
• The initial connection and start-up can be a bit scary, but they really are very simple equipment to use.
• The equipment is more bulky with respect to USB microphones: microphone + cable + sound interface …

Recommended XLR microphones