20 MAY 2017

written by Mike

INTRO

TO MICROPHONES

In this article, I want to share with you an overview of a recording microphone. Microphones or mics are the basic instruments of capturing sounds. You have one inside your laptop, your phone and your camera. Even in a smart watch.

Before we dig deeper in microphone placement techniques and various recording tips you need to learn more about mics.

What is a condenser? Dynamic?

When you work with professionals and experienced sound engineers, you will learn that choosing the right microphone is number one thing one the list. Every audio professional will have their preferred mic, and least favourite too. Whatever you want to do you will need to understand basic characteristics of a recording microphone. So, let’s start with that.

When it comes to elemental features of a mic, three things matter.

A transducer, frequency response and directionality.

I. Transducer

A transducer in a microphone transforms acoustic energy (e.g. your voice) into electrical energy. How a microphone registers sound depends on a type of a transducer. Two main ones are Dynamic and Condenser.

Dynamic

Dynamic microphones are quite cheap to build and robust.

So how do they work?

Dynamic mic operates on small electrical generator built from a diaphragm, voice coil and magnet. Let’s say you are recording yourself for a YouTube channel. The force of your voice, as a sound wave, makes a diaphragm vibrate. The diaphragm can be described as a thin membrane hidden behind microphone’s metallic mesh.

At the rear of the diaphragm is a voice coil, a coil of wire, which also vibrates. A small magnet forms a magnetic field around that wire. Physics. The movement of that coil within the magnetic field generates electrical signals that correlate to the force of your voice. Because dynamic microphones can survive in the toughest environments, they are number one choice for live performance.

It is almost impossible to overload a dynamic microphone. Good examples are Shure SM58 we use them for live sound and Shure SM57 another classic and cheap microphone. If you don’t know which one to buy you should get SM57. It will do the job.

Shure SM7B is a classic dynamic microphone used by sports commentators and radio presenters.

Have you ever wondered how is it possible that they shout their heads off, and the sound stays clear?

In most cases, Shure SM7B is the answer. My favourite dynamic microphone would also be Beyerdynamic M201. A smooth sounding mic that works great on a snare but also on some louder singers.

Condenser

Condenser microphones are a bit more complicated than dynamic, more sensitive and more expensive (well, it depends…).

The basics of a condenser mic lie in a capacitor.

The force of your voice will resonate a thin metal or metal-coated membrane that sits in front of a rigid backplate. The space between the two contracts and the motion produces electrical signals.

Now, the biggest difference between dynamic and a condenser is that the latter requires additional power to run. There are two ways to power up your condenser microphone.

First one is with batteries, second, we call phantom power. Phantom power runs through the microphone cable from the interface e.g. mixing desk or audio interface. Condenser microphones are sensitive and delicate. They also produce more noise than their dynamic siblings. Maximum sound level specification means that if you shout into a condenser, there is a high probability that the recording will distort.

Good condensers are great in capturing a wide dynamic and frequency range. Try recording an acoustic guitar with a condenser and then with a dynamic microphone. You will hear that condenser will capture the smallest nuances and movements of the guitar.

A classic pair of condenser mics would be AKG 414. Sound engineers often use them as overheads for drums and choirs.

Neumann U87 is a classic studio microphone used for vocals. It is the first choice for ADR recordings or dubbings. Recording sound on sets also requires a sensitivity of a condenser. Microphones such as Sennheiser MKH-416 combine a subtlety of a condenser transducer and a robustness of a dynamic microphone. Remember also to buy a pop shield and keep an eye on a noise level.

II. Frequency response

Frequency response it the reason every music producer, sound engineer or a foley recordist has a preferred microphone. Transducer decides how the sound is captured; frequency response chooses what to capture.

Let’s say you recorded your dog. If your recording sounds 100% the same as your dog in real life, it means that the microphone that you used has a flat frequency response. It didn’t change the sound. Microphones with the flat response are used for measuring acoustics of space and can be quite expensive. Also, you don’t want to use them on your recordings.

Why not?

Well, the sound of a microphone can make your recording better. It can add depth and warmth. It can capture smooth low frequencies or sharp high frequencies. It can omit frequencies that you don’t want. Some microphones will add punch to your drums or presence to vocals. Other times you may wish to use a microphone with a detailed response.

You don’t want to omit anything when recording a wide frequency instrument such as piano. Before using a microphone check its frequency response and its desired use. It’s also good to experiment with different settings.

III. Directionality

The last one on our list is directionality.

Directionality describes the most sensitive side of a microphone. Polar patterns describe how a microphone will pick a sound and what is its best position for it. There are quite a few polar patterns to choose from, but today I will focus on three main ones.

Omnidirectional

The omnidirectional microphone will register sound at all angles. The polar pattern covers 360 degrees. It means it will pick up the sound from the back as well as from the front. With the same intensity. These polar patterns are great if you want to capture an ambience of a place, something like an inside of a cave.

Another use is to leave an omni in the room as a so-called ambient mic. You can then add this additional layer to your mix later on.

Unidirectional

As you probably guessed, unidirectional microphones will register sounds from one particular direction more than from others. Most popular will be a cardioid, a heart-shaped polar pattern. It will pick up less ambient sound than an omnidirectional microphone, and it works great when you want the focus.

For example, if you wish to record a dialogue on set you don’t want to capture a technical crew that is chatting in the corner. Unidirectional microphones are made for this kind of stuff.

Bidirectional

Bidirectional microphones are sensitive at front and back but omit material from their sides. They are great for vocal duets and individual stereo recording techniques such as mid-side, M-S.

This polar pattern is used when you want to dismiss unwanted sources of sound. As I mentioned before these are helpful on movie sets, during live music recordings or any environment with more than one sound source. Correct microphone placement is a skill in itself, and I will share with you some advice on that in another article.

To know your equipment is essential.

How it all works and why you want to use it?

These are the questions that you need to ask yourself before making any decision. Microphones are everywhere. You don’t have to know all the details and technical specs of their build, but don’t be ignorant. When it comes to selecting the right gear, ignorance is not bliss.

04 MAY 2017

written by Mike

SOUND RECORDING BASICS

Throughout the years, capturing sounds has evolved in a dramatic way. From phonograph to a microphone in a mobile phone. From analog to digital.

People still use analog recording, but I will focus on a few aspects of digital recording. Digital recording is the most common, cheapest, and easiest method of capturing needed sounds.

Sound recording can be fun, exciting, hectic, tiresome, laborious and unforgiving gig. But with a few guidelines and basic knowledge, the difference between amateurish and well sounding production can be huge.

Just try to remember last Internet video that you watched.

Was a picture quality good?

What about the sound?

How many times do you have to play with your volume control when switching between videos?

How noisy are the recordings of that famous vlogger you follow?

The forgotten art of quality sound recording tells a difference between a wannabe Internet star and a professional.

RECORDING EQUIPMENT

The simplest setup for recording sound would be a microphone, cable/lead and a sound recorder. Connect the microphone via cable to the recorder and voila!

Of course, there is a lot more to it, and professional recording sessions are much more complicated. But the basic principles stay the same.

Let’s have a quick look at the basic three components of the setup.

Microphone

There are a lot of heavy, big books on microphones alone. But to have a good understanding of the subject we can distinguish two types of microphones: dynamic and condenser.

Condenser microphones are bit more sensitive than dynamic. You can use them to record vocals in the studio, wide range instruments such a piano or violin. DPA Microphones debunks some of the myths here. 

Cables/Leads

Most common cables used to connect a microphone to the recorder are XLR balanced connectors. They can carry the sound over a long distance without inducing any unwanted noise.

USB cables that connect a microphone to the computer are also popular.

Sound Recorder

The subject of sound recorders is wide as the sea but just try to think about it for a second. Anything that can capture a sound is a sound recorder. A mobile phone is the most common one; a simple stereo recorder like Zoom H4N can be handy too. At the professional end, there are a lot of different kinds of sound recorders.

Small, portable ones we use for interviews. The medium we can use for recording dialogue on a movie set. Recorders from Sound Devices have a good opinion.

For a beginner, a simple, direct USB microphone will do but even a basic setup through audio interface will always get you a superior quality.

TECHNIQUES

Techniques of recording audio are an art in itself. There is a choice of correct microphone, the placement of the microphone, recording levels and setting. These are only a few variables that a good sound engineer has to take into consideration. It is important to research the techniques that someone else used for the recording that you want to do.

Using an unusual placement or setup can lead to unexpected and often exciting results. Like using a “trash mic” for example. Every recording requires a different approach. It is important to have an open mind but also a good knowledge of basic procedures.

Have your standard set up in place and then another one as an experiment. And if you are just starting that will often be the case.

COMMON RULES

Like in everything experimenting and learning from mistakes is a great thing. But there are a few standard rules that you should apply if you want your recording to sound awesome.

Be wise when choosing the microphone

– it can mean a great difference to a general sound of your recording.

Use intelligent microphone placement

– remember the last time when you had to raise the volume to the maximum to listen to that famous vlogger? Or maybe you had to turn it right down?

Know your set up

– microphone, cable, and recorder. Using USB microphones is fine but even with the most basic audio interface connected to your computer the results will be much better.

Know your volumes

– a quiet recording will result in a noisy recording. Turn the volume up, but record too loud and the distortion will ruin your work.

Always record more than you need

– you will have more options to choose and also a backup if something happens to the original recording.

Do a test and listen back to it

– going back to the placement and choice of the equipment. It is always better to get it right at the beginning rather than trying to correct it later on.

Know your basics

– audio recording can be a complicated subject. The basic knowledge of recording, compression and EQ will make a big difference to your final project.

Have fun!

– Experiment and have fun with the process. The more you learn hands on, the better your projects will sound in the future.

It doesn’t matter if you are working on your Internet video channel, making a family holiday video or recording an interview at work. Follow these simple rules and each one of your productions will be better in the end.

Next time when you watch something, focus on listening. Not only on music but also on dialogue and ambience.

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