The Essential Guide to Understanding Microphones for the Filmmaker

How do you get good vocal clarity in your recordings?

A Brief Intro…

Getting your vocal speech recording right is fundamental to your film-making and content.

As most content and video productions have vocal speech recordings – be it podcasts, film advertising, corporate video or more – it is the core tool in getting your message across.

To get excellent vocal production in your content, you need to start with a good basic “raw” recording.

Think of the “raw” vocal recording as your building foundation – if it is good, anything you add to it in post production using vocal processing software will just enhance the magic and make it sound even better.

In this article I will be starting with the first building block in achieving a good vocal recording – the microphone.

In this article I will cover the following:

  • Explain the basic microphone types.
  • Describe the most suitable microphones for different applications.
  • Highlight what you should look for when selecting a microphone.
  • Demonstrate how to read and understand microphone technical data.
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There are three fundamental things to consider when recording – tick these three boxes and you are well on your way to success:

  1. Pick the right microphone for the application.
  2. Know the right placement of the microphone.
  3. Consider the recording environment for your microphone.

How to pick the right microphone for YOUR production?

In order to impress the seasoned sound engineer and pick the right microphone for the job, you need to know the main three types of vocal microphone on the market – and here they are:

1. Dynamic Microphone.

2. Condenser Microphone.

3. Ribbon Microphone. (Technically a sub-division of dynamic)

There are other types, but these are the main ones and if you own a microphone it will most likely be one of these three.

The different types have different audio qualities and therefore each type will bring something different to your recording.

The names, correspond to how the microphone operates internally.

You don’t need to know the internal operation details unless you are an electronics engineer but in a nutshell, how they capture sound differs by their mechanical & electrical design. This difference in design adds different audio properties.

To summarize microphone operation in one line and to keep this simple –  “a diaphragm” which is a really thin piece of material inside the microphone, vibrates when you project sound at it, this then converts the sound waves of your speech to an electrical signal which can be amplified and recorded.

Here is a detailed overview of the three main microphone types.

Dynamic Microphones

  • The dynamic type is the least sensitive of the three. (Least sensitive in sound design terms means that they won’t pick up every sound in the environment, like your dog snoring next door!)
  • Often, they can be significantly cheaper as their internal mechanics & circuity is not as complicated. Don’t mistake their cheaper price for lack of performance however!
  • Of all the microphone types, they are the most durable and robust. They are used in live stage performances most commonly due the amount of abuse they can take without breaking.
  • They are used in the music recording world for loud instruments, like drum kits as they can absorb the louder sound without causing internal damage.

Condenser Microphones

  • The condenser type is most commonly used in the recording studio.
  • They are superb for achieving clean vocal recording.
  • Be warned that the large diaphragm condensers microphones, due to their excellent sensitivity, will pick up noise in the environment. A large diaphragm condenser is the type of microphone that could pick up the sounds of your dog snoring next door! Ensure you use in a studio or quiet environment.
  • Wonderful at picking up detail and clarity in a recording.
  • Really should be used with a shock mount as they are more sensitive to picking up sound. This is a suspension system within which the microphone is mounted to protect it from noise and vibration.
  • Comparatively more expensive than dynamic microphones and need more care when handling as they are less robust – drop one of these or put it in front of a loud sound and there is an increased chance that you will damage the internal mechanism.
  • Condenser microphones, due to the internal circuitry, needs external power from another source. This is called a phantom power and is typically 48V. Your audio card or audio interface will need to be able to provide a 48V supply to your condenser microphone in order for it to work. You can buy an external 48V phantom power supply if needed however.

Ribbon Microphones

  • The ribbon microphone is similar in operation to the dynamic microphone but has a very thin metal ribbon as part of the internal mechanical design, hence the name. Technically, they are a sub-division of dynamic microphone.
  • Of all the microphone types, ribbons are one of the most sensitive to sound.
  • Being the most sensitive, they really should be used for very quiet and controlled recording environments. They pick up everything!
  • Very fragile. Needs to be handled with care as the metal ribbon can be easily damaged.
  • Recommend only for controlled studio environments or very controlled conditions – for this reason I don’t recommend them, certainly not as a first choice. 

What should you consider when shopping for a microphone?

Ask yourself the following questions:

  1. What sounds am I recording? – (Vocals, musical instruments, sound foley etc…)
  1. Where will I be recording? – (Indoors, outdoors, noisy environment, indoors but still a bit noisy)
  1. Where will I place my microphone? – (Will you be recording a few people sitting around a table with the microphone in the center or will the microphone be placed directly in front of your speaker or of to the side etc…)

If you honestly consider the above three questions and understand the technical data which I am about to explain you will be well on the road to success to picking the right microphone and using it correctly. 

The Right Microphone for Your Content Type

I will give you a brief list of what microphones are good for each application but first, I need to share some of my experience so you don’t make the same mistakes as I did when I first started out or even in later years as a seasoned engineer!

If your focus is vocal clarity, consider the large diaphragm condenser microphone type.

Personally, I would never record vocals on anything but a large diaphragm condenser microphone.

However, there is one thing you need to watch out for with large diaphragm condenser microphones – they pick up everything, not just your vocal recording.

So, if you record regularly in a standard town house where a neighbor cuts the grass every second day, you will hear the hum of the lawnmower on your recording, despite closed windows and curtains. I have been there and dealt with the frustration…

Of course, this does depend on the quality of the microphone and you can apply some acoustic treatment to really cut out noise, but please be aware that large diaphragm condenser microphones, although wonderful for vocal recording, are very sensitive and do pick up lots of environmental noise if left unchecked.

TO MAKE LIFE EASY, HERE IS A LIST OF APPLICATIONS AND A CORRESPONDING RECOMMENDED MICROPHONE IF YOU ARE ON A BUDGET.

YOU CAN STICK TO THIS LIST OR USE THE “VIEW FULL SPECIFICATIONS” LINK I HAVE ADDED AS A BENCHMARK TO PICK YOUR OWN.

Microphone Environment 

Where will you be recording?

Considering your recording environment will dramatically improve your recording quality and experience.

The right microphone matched to the right environment will give you a clear vocal recording with minimal interference and external noise.

When considering your recording environment consider:

1 – Environmental Noise Sources

2 – Acoustic Treatment

3 – Outdoor or Indoor Recording

Noise Sources

Avoid noise at all cost.

Noise could be the low hum of your central heating, the high frequency of a neighbor drilling in their garden shed or just the consistent fan noise from your PC….there is noise everywhere! Think about your environment and consider what noise you need to filter out.

If there is noise recorded on your vocal recording it is extremely difficult to reduce and nearly impossible to do without effecting the overall quality of your recording.

Think about it – you are in the middle of a podcast interview, full flow making your point and someone bangs a door shut. That sound of banging a door is interwoven with your vocal speech recording.

Unless you are lucky enough that the bang happened just when you paused or took a breath, you cannot remove that sound of the door banging without removing or degrading some of your vocal recording quality.

There is software and techniques which I can show you to help with improving poor recordings, removing noise and rumble but that is a topic for another day as it is involved.

Sign up to my mailing list or follow me on social media to get a notification when I publish my article “how to clean vocal recordings using post production software”.

Acoustic Treatment

If you are recording indoors, there is a lot of basic acoustic treatment you can use to help out.

There is still a lot of debate among us technical acoustic folk as to how effective vocal shields and basic acoustic foam is in helping the home studio recording engineer or content creator, however, if used correctly, you can make an improvement. It is all about knowledge and using the right tool for the job.

Now acoustic treatment is a really big area that I will explore in detail later. This is a particular passion of mine. For now, consider some basic tools like vocal shields to help drown out and absorb some environmental noise. 

I will be discussing acoustic treatment and vocal shields in greater depth in a future article.  

Sign up my mailing list to get a notification of when this information is released. 

Outdoor Recording

So much recording is done outside due to the massive surge in content creators on location. This introduces a new level of technicality to your recording.

If you are outdoor recording, you really need to purchase a microphone suited to an outdoor noisy, windy environment and factor microphone wind shield accessories cost into your price.

A directional or shotgun microphone often works best in outdoor situations as you point the microphone at the sound source and most of the surrounding noise is ignored or reduced. 

Microphone Placement 

Where is your sound source & where is your microphone?

Every microphone has an optimum position for recording. In this optimum position it will pick up the most sound. 

Every well manufactured microphone will come with what we call a “polar pattern” diagram. 

This shows you the optimum recording position for your microphone i.e. how to position the microphone so that it will pick up the most sound.

When you shop for a microphone online, look out for this pattern.

Here is what they look like and their corresponding names.

And here is how you understand and read these charts:

The black solid line on the diaphragm is the position your sound source should be relative to the microphone so the microphone will pick up the most sound.

You can find out the polar pattern for your microphone by looking at its data sheet.

Let me explain via an example:

Lets assume you are recording an around the table podcast. In this situation you would place your microphone in the middle of a table and everyone would sit around in a circle.

In this situation you need a microphone with an omni-directional polar pattern as it can pick up sound sources from all around the microphone. Some microphones have more than one pattern. Always ensure you physically look at the microphone as some microphones are capable of multiple recording positions and have switches to switch between patterns for optimum recording positioning. 

Frequency Response

The frequency response of a microphone is one of the most important things to check out, however, as it is technical and all “graph like” many just smile and nod and ignore it.

In very simple terms it explains the sound spectrum that the microphone can reproduce. It is often called the sound signature.

Every sound has a frequency. The human ear can hear between 20Hz and 20kHz. Each sound from drums to guitar to vocal will have a frequency that will fit somewhere in that band.

Let me give you an example of an actual microphone and frequency response to help explain how to read the frequency response graph of a microphone.

Shown below is the frequency response of an entry level condenser microphone – an MXL 990.

In an ideal world the graph would be flat – no peaks and no dips – this graph would tell us that the microphone could record sound perfectly – exactly as you are hearing it.  

You will never find a perfect straight line curve as the electronics of the microphone or microphone cables or something in the environment will influence how sound is recorded.

The best you can hope for is a microphone with a “flatter” curve and you will not find such  a microphone until you hit the really expensive top end of the market and microphones such as the Neumann U87. (My favorite microphone of all time!) 

Here is how you read the graph:

The chart has dB (sound level) on the Y -Axis (that is the axis going up) and has Hz (Hertz – frequency) on the X-axis (that is going across).

Remember, we are assessing this microphone for its ability to record human vocals. It is important to know that the male vocal range is around 80Hz to 180Hz and the female is around 160Hz to 250Hz.

Reading the chart from left to right you can see that the curve is below 0dB until it hits 50Hz. This tells me that this microphone will struggle recording sounds below 50Hz. This is the frequency range of deep bass so as a vocal recording, it does not effect my application. Plus it means that my microphone will not pick up any low rumble noises so this is good.

Between 50Hz to 300Hz it is pretty “flat” (i.e. no dramatic peaks or dips in the curve) so therefore, should capture male and female voices very well without dramatically adding to or changing the sound. 

If you follow the curve from left to right you can see it starts to go up at around 6kHz to 10kHz.

Having a boost in this region will add a crispness and definition to your vocal recording so can be a very good thing.

In this particular microphone, the MXL 990, it adds brightness and clarity and I find it great for recording low male vocals as it just gives it that bit of brightness which I like. 

And that is it – you have read your first frequency response curve! Don’t panic if you still don’t get it. Sometimes, just trust your ears as they are always the best measure.

Finally – before purchase double check the following:

1. Connections 

Remember to always check the connection type required for a microphone and ensure it is compatible with your recording equipment.

2. Phantom Power

I mentioned this earlier but I am going to say it again as so many forget – if you buy a condenser microphone you will need a phantom power supply of 48V to power it.

Your audio card or audio interface may be able to supply this, however, if not you can buy an external phantom power source.

One of the best microphones on the market is the Neumann U87 and it is one of my favorites.

At a cost of around £2500 however, it is out of reach for most content creators.

Did you know that you can short term hire high end microphones for a low cost? Hire can be as little as £20 per week.

Have a look in your local area for professional sound hire outlets. There are many in the UK which allow you to hire high end microphones before committing to purchase.

NEUMANN U87

[VIEW FULL SPECIFICATION

PRICE £2200 – £2500

CONCLUSION

The first step in producing good vocal recordings, is to start by capturing a clean, dry recording of the vocal.

Clean and dry means no noise and effects – only the voice without interference should be audible.

To achieve this, you need to start by picking the right microphone and to pick the right microphone you need to understand a few basics.

Firstly, there are three main microphone types, namely, “Condenser”, “Dynamic” & “Ribbon”.

There are others, but these are the top main three and if you own a microphone already it will most likely be one of these.

These three microphones differ mechanically in how they pick up sound. As a result, each type has advantages and disadvantages when applied to different recording scenarios.

In a nutshell, for recording high quality vocals I recommend a large diaphragm condenser type, however be aware that they are a sensitive microphone and will be more prone to picking up external noise.

Condenser microphones are great for studio or quieter atmosphere recordings but not good for picking up vocals in noisy environments as you will hear everything.

Dynamic type microphones are more robust and durable than the condenser type and won’t pick up every detail in the environment, hence why they are used for live performances. However, they are less sensitive, and you will not get the detailed clarity or brightness that often sounds great on vocals. Still a great option however.

The ribbon type microphone, a sub-division of the dynamic type, is the least common and personally I don’t recommend this type of microphone.

Some people love ribbon microphones but for the average filmmaker and content creator, it is too delicate (i.e. easily broken) and requires a very quiet and controlled recording environment. 

In my opinion, it does not achieve anything special over a condenser microphone for low budget recording.

When choosing your microphone, always consider your recording environment and application.

Consider any external noise that you need to filter out, be it the sound of your PC fan in the studio or wind noise when recording outdoors.

Picking your microphone for your recording environment will set you well on the road to success.

When buying a microphone be sure to check out the data sheet and look out for the “polar pattern” and “frequency response” curve. 

The polar pattern tells you the optimum position from which your microphone will pick up the most sound. 

The frequency response curve will tell you how well the microphone will pick up certain frequencies. 

The male vocal range is around 80Hz to 180Hz and the female is around 160Hz to 250Hz so ensure the curve is above 0dB in this frequency range and without any sharp peaks or dips.

Finally, do not forget that you need to connect your microphone to your recording gear so ensure you check all your cables & connections before purchase.

In addition, condenser microphones need an external 48V power supply to operate. This can be supplied by some sound cards and audio interfaces, but if not, you will need to buy an external 48V power supply.

At the end of the day, I always end by saying “trust your ears”. There are so many opinions out there on what sounds good, but sound is so subjective, always trust your own ears.

Do you have a microphone that you love and want to shout about? Please comment and let me know.

If you found this article useful, please consider sharing and helping other filmmakers and content creators capture great vocals recordings by understanding their microphone. 

About the Author

Louise Byrne BEng, MSc.  has been a professional engineer and music producer since 2008.  A member of the Audio Engineering Society she divides her time between designing pro audio equipment for the music industry and writing music for visual content & artists.

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