How to choose a mic: The basics

You’d think a mic would be easy to choose. Learn all the hidden complexities before buying this game-changing instrument.

Content is king

That goes without saying. But the medium that the content is carried along matters as well. The mics, the music, the setup, the location: everything fits together to make your show what it is.

Some people get by without any real setup. Like a crazy guy ranting in his pickup truck, or a guy following people around saying it’s “story time”. Those things work because of the novelty, but after the 50th angry truck guy, the novelty fades off.

Sadly, the awareness of the crap and lazy production quality begins to build up.

Then there’s also the really well-produced stuff that is made to look like it’s just an angry guy randomly ranting. Jonathan Pie, anyone? He turns off the camera, rips off the mic, and starts a raging monologue to the viewer. It’s like a camera and mic aren’t still trained on him and you’re his pal standing off-camera. But if you’re watching his clear face and listening to his crisp voice, they very much are.

Just getting by

As the creator, you control the production. Maybe it’s better to go cheap and build up, or maybe it’s better to start off as high quality as possible. This all depends on your aims, ambitions, and appeal. But it’s generally better to have a high level of production and look low budget. You don’t want to actually just have a bad level of production because you don’t know what you’re doing.

It is possible to just get by on the cheap without knowing what you’re doing and be immensely successful. The odds of doing that though are one in a billion (mazel tav to you if you’re one of those) and it takes a whole lot of luck.

The rest of us need to work at it. And working at it means research and making the right choices.

One of the first and easiest thing we have control over? Mics.

In this guide, we’ll first talk about the fundamentals of how microphones work. Then in the next part, we’ll go over dynamic mics and condensers, along with a few other variants. It’s important to know the basics before taking the plunge and making a purchase.

Condenser mic in a studio

Condenser mic in a studio

How does a microphone work?

In general, microphones work the same way as your ears. Sound vibrates a membrane, which transmits an electric signal that’s read and translated by your brain. The same goes with a microphone: sound vibrates a diaphragm or ribbon which then transmits an electric signal.

The electric signal might then be amplified and left for your brain to work out. Or it might be sent to a computer to be translated and manipulated further. What’s amazing to me is how many layers of membranes a signal must travel through before you can sit back in your couch and enjoy the latest beats from Grimes.

Understanding that basic bit of physics, we also need to learn a few other factors before throwing down a pile of dough and making sure it won’t be our latest paperweight. Read on for these primary bits in determining the right mic for you.

Directionality

This refers to which direction the microphone picks up incoming sounds. There are essentially three types of directionality: omni-, bi-, and unidirectional.

Omni-directional mics pick up everything around them, 360 degrees. This is the best for recording ambient sounds or if your music group was practicing and needed a quick and easy set up. Or perhaps you’ve got a group of vocalists and you all need to crowd around a single mic.

If you’re a podcaster on a budget and want to record conversations with several people, this might be the type for you.

Omnidirectional microphone

Polarity pattern of an omnidirectional mic

Bi-directional mics read anything on two opposite sides of it. If you were looking at a compass, it would pick up North and South but not East and West. They’re often called “Figure-8” mics, because they pick up things in the shape of that number.

These are also not a bad option for podcasters who are just planning to have one guest at a time and want to sit on opposite sides of a table, and it can also be beneficial for single podcasters, depending on how the room is treated.

Unidirectional mics pick up sounds from only one direction. For the majority of uses for YouTubers and podcasters, unidirectional is the best as it can maintain focus on one direction, and thus, one speaker or object, and it can cut off most of the background sounds that aren’t in that direction.

It doesn’t stop here though, as there are several types of unidirectional mics.

Unidirectional mics

There are four kinds of unidirectional mics:

Subcardioid mics pick up over half the sphere, which is why they’re also called “wide cardioids”. Or as I like to call them and annoy engineers, “half-omnis”. These are great for a group of singers or quiet stage settings.

They’re probably not good for a home podcasting studio as they’ll pick up your heavily-breathing, potato chip-eating friend standing over your shoulder watching you in awe and wonder.

Subcardioid

Polarity pattern of subcardioid microphones

A supercardioid is often what you’ll see on a movie set or a camera. It has a super tight angle of detection, and the sides are cancelled out almost altogether.

This might sound great, but when you’re at the desktop and trying to get comfortable, it’s definitely not ideal, as it’s the least flexible on angle and you won’t be able to move your head or shift your position the slightest.

Polarity pattern of supercardioid microphones

Polarity pattern of supercardioid microphones

Then there’s hypercardioids, which is like a supercardioid on steroids. They pick up sound from the rear and the front, but have an even tighter pickup angle with almost no leakage from the sides. The drawback though is that sound leaks in from the opposite end.

Hypercardioid microphone

Polarity pattern of hypercardioid microphones

Lastly, the plain jane cardioid mic is the most common mic and probably the type you’ll want to get for YouTubing and podcasting. It picks up sounds in roughly a heart shape, and is easily the best for microphone beginners and home studios

Cardioid microphone

Polarity pattern of cardioid microphones

Frequency response

The frequency response curve indicates which frequencies the microphone picks up best, and tells you quickly whether the mic is more suitable for vocals or instruments. For a vocal mic, you’ll want one with a range from 80 Hz to 15 kHz.

That said, different vocal mics perform differently at smaller frequency ranges, even though their overall response might be the same. For this, you should check the response curve.

In general, the flatter the curve, the truer the reproduction, and if you’re recording at home or in a studio, with less sounds to intrude, you’ll want a flatter response curve. If you’re recording on the road, then you’ll want something with a bit of a boost at the mid-upper range so that it truly focuses on your voice’s dynamics and cuts out cars and hums.

Sensitivity and SPL

To put it short, sensitivity refers to how soft a sound a mic can faithfully pick up and how loud it can pick up until it clips. A mic that can pick up very very soft sounds, for instance, will probably clip easily with loud noises.

Digital and analogue mics interpret sensitivity in different ways, and even different companies have different methods of measuring this.

You’ll on occasion see the acronym SPL, which stands for Sound Pressure Level. This is a relative loudness measurement reference, from the loudness of a jet engine to that of a whisper. Microphone companies like Audio-Technica often state their sensitivity in dB, comparing it to the SPL standard.

Reading sensitivity

The dB measure of the sensitivity will always be in negative numbers, and the closer it gets to 0 the more sensitive it is. If you’re doing ASMR for instance, then you’ll want that number as high (closest to 0, remember we’re dealing in negatives) as you can get.

Some things to keep in mind:

  • Condenser mics tend to be more sensitive than dynamic mics
  • More sensitive doesn’t mean better or worse
  • Location and situation is a large factor in how sensitive a mic you need

Location and sensitivity

A podcaster or YouTuber sitting at their desk might want a more sensitive mic so that he doesn’t have to lean in all the time. If you treat the room right, then you won’t have to worry about outside sounds too much and you can keep the mic off screen.

On the other hand, if you don’t have a nicely treated room, there’s a lot of outside sound going on, or a lot of people involved (like Joe Rogan, who often has three to five people in a show), you might want a less sensitive mic.

If you’re outside, you might want a more sensitive mic as long as it has a really tight directional shape, like a shotgun mic that you might find on camcorders or at movie sets.

But maybe you’re a one-person act and will just carry a mic close to your mouth, then you’ll want something with a lower sensitivity so it won’t pick up all the ambient sounds and will go softer on the pees and esses.

The mic that’s right for you

The main lesson here is to understand the situation you’ll be recording in, and apply that to what kind of mic you’ll need. There is unfortunately no “one mic fits all”, but at least if you understand the various measurements, then you can figure out the one that’s right for you.

Stay tuned for the next blog to understand the difference between condenser mics and dynamic mics.

2020-07-14T09:09:32+00:00July 27th, 2020|Podcasting, YouTube|0 Comments