Microphones are essential pieces of equipment for anything that involves audio. That TV show you're binge-watching? The sound effects are just that good because the engineers chose the right microphones to capture unique sources of sound.

Whether you're looking for an all-purpose studio mic or something more specific, there are a number of factors to carefully consider before making a purchase. Let's jump right in.

1. Microphone Type

There are three primary types of microphones: condenser, dynamic, and ribbon. All three use a different technology to convert sound waves to electrical signals. Because of these different conversion methods, each type of microphone will be better suited for different types of sound waves.

Let's have a look at these microphones and which ones you'll find most useful for your recordings.

Condenser Microphones

M7 Condenser Microphone
Image Credit: Matt Vanacoro/Wikimedia Commons

Condenser microphones include two subcategories: large diaphragm and small diaphragm.

Small diaphragm condenser mics are very sensitive and have an excellent high-frequency response. They're ideal for delicate instruments such as cymbals, hi-hats, and percussion instruments.

Large diaphragm condenser mics are also sensitive to high frequencies but have an overall better frequency response that extends to lower frequencies, which makes them ideal for recording vocals and acoustic guitars. This is usually the mic you'll see in podcasts or recording booths.

There are some downsides to the condenser mic; they're very sensitive which makes them more susceptible to damage, they're expensive, and they need an external power source usually derived from an audio mixer or interface (phantom power).

Dynamic Microphones

Shure SM58 Dynamic Microphone
Image Credit: Nicolas Esposito/Wikimedia Commons

If you're just starting out with any type of audio recording, a dynamic mic is your best bet. They're cheaper than condenser mics and more durable, so they'll withstand a little more abuse if moved around—also perfect for a beginner who might fumble when setting it up.

Because of their higher durability, it makes them less sensitive and requires a higher SPL (sound pressure level) to pick up sound. This makes them ideal for guitar amps, drums, and vocals in live performances. They also don't require phantom power.

Ribbon Microphones

Royer R-122 Active Ribbon Microphone
Image Credit: Alex Regan/Wikimedia Commons

The ribbon mic frequency range is closest to that of human hearing, so its sound output is the most natural compared to other microphones. They're great at picking up delicate sounds, which makes them ideal for things such as ASMR, but they also aid in taming harsher sound waves like that of guitar amps.

The trade-off: they're very fragile, so you need to be careful when handling them. And the conductive ribbon on the inside will get electrocuted if you feed it 48V phantom power—don't make this mistake.

2. Directionality (Polar Pattern)

Microphone directionality, or polar pattern, describes the dB (decibel) sensitivity of the microphone from different angles. This means that some parts of the capsule (the head of the microphone) will pick up sound waves more efficiently, while other areas lack that sensitivity.

There are two main polar pattern categories: cardioid and directional. Both branch off into several unique polar patterns. Let's look at the most common ones and the sounds they're best suited for.

Cardioid

Cardioid Polar Pattern
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This is the most common polar pattern, found in most dynamic mics and some condenser mics, and is best suited for vocals. Its heart shape picks up sound primarily from the front, some from the sides, and has little to no sensitivity to sound coming from the back—this helps prevent feedback.

Hyper-Cardioid and Super-Cardioid

Hyper-Cardioid Polar Pattern
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A hyper-cardioid pattern is a little tighter in the front compared to cardioid and has added sensitivity in the back. Mics with this pattern properly hone in on the sound source, making it ideal for sound in film or an instrument setup, and can also be used for vocals. Just be careful of the added sensitivity at the back.

Super-cardioid has a near-identical pattern to hyper-cardioid, with slightly more sensitivity in the front, and less in the back.

Omni-Directional

Omni-Directional Polar Pattern
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An omni-directional pattern has a 360-degree pickup sensitivity. These mics are ideal for any type of circle formation such as a choir, or for capturing the sound of the entire room.

Bi-Directional (Firgure 8)

Bi-Directional Polar Pattern
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Microphones with a bi-directional pattern have equal sound sensitivity from each side but will reject sound from the front. This is ideal for when you want to record two sound sources at the same time while eliminating other unwanted vibrations. Almost all ribbon mics have a figure 8 polar pattern.

Unidirectional (Shotgun)

Unidirectional Polar Pattern
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You've probably heard of a shotgun mic before. Well, it's named after its polar pattern. This pattern is meant to pick up the sound that it's directly pointed at, as well as sound from far away. You'll often see these attached to the top of a camera during TV recordings or sports events. They're also great for isolating instrument sounds.

3. Proximity Effect

The proximity effect is the increase in low-frequency response whenever the mic gets close to the sound source. You might have noticed how much deeper someone's voice sounds when they're very close to the mic, especially male voices. That's the proximity effect.

The strength of the proximity effect will be determined by the mic's polar pattern. The more variation there is in the pattern, the more prevalent the effect. This means that omni-directional mics don't exhibit the effect at all.

Related: Tips for Recording Studio-Quality Vocals at Home

The proximity effect can be a cool way to thicken up a sound source, but it also poses a problem; the mic will pick up more plosives (consonant sounds like p, t, k, and b). That's why singers often use a pop filter with their mics.

4. Frequency Response

Most microphones have the standard frequency response of 20Hz - 20kHz that correlates with the human hearing range. What matters is which frequencies they're most sensitive to. This is determined by the microphone type and design, and will highly influence the sound output.

Microphone Frequency Response Chart
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Before purchasing a microphone, we recommend looking up its frequency response chart, as well as a frequency response chart of the sound source you want to record, and cross-referencing them. Above are the frequency response charts of a condenser and dynamic microphone.

Keep in mind that you don't always have to use a mic with the same frequency response as the sound source. For example, using a dynamic to record an acoustic guitar will be great for percussive strumming, while a small diaphragm condenser is well-suited for the higher frequencies produced when using a guitar pick.

5. Maximum Sound Pressure Level (Max SPL)

The max SPL of a microphone refers to the loudness of the sound source it can handle before distortion, measured in dB. Again, we recommend cross-referencing the max SPL of the microphone with the maximum dB of the sound source so you can avoid distortion as well as potentially damaging the mic.

For example, dynamic mics have a max SPL of about 160dB, which makes them ideal for recording snare drums that emit between 90dB - 120dB.

6. Connectivity

Microphones can either plug into a preamplifier or a device that has a proper audio input. Preamplifiers can be standalone or built into audio mixers or interfaces. And a device with an audio input can be your computer with an audio jack port.

Of course, different microphones have different types of connectivity, and you need to ensure to get one that can connect to the equipment you have, or you might need to splurge a little to obtain the right equipment. If that's not an option, look into getting an adapter.

Various XLR Connectors
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Most mics use XLR connectivity, which ranges from 3-pin to 7-pin connectors. The number of pins is determined by the mic requirements, such as ground/shield, positive and negative polarity, unbalanced signal, left and right channels, and even LED lights on the mic that needs a power source.

TRS Microphone Cable
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Tip-sleeve (TP) or tip-ring-sleeve (TRS) connectivity is probably something you're already familiar with; it looks like your headphone jack. They come in a variety of sizes.

Related: USB vs. XLR Microphones: Which Should You Get?

Some microphones also come with USB connectivity. These can plug straight into the computer with your DAW (digital audio workstation, aka the program you're using to record and mix). Check out these USB microphones if you're in the market for one.

Choose Your Microphone Wisely

After reading this, you might be overwhelmed by all of the factors to consider when buying a microphone. But, microphones are a pricy investment, and we want you to get the best bang for your buck, as well as avoid damaging it.