Microphone Characteristics: Sensitivity, Frequency Response, Polar Patterns & More

Today we’re going to talk about microphone characteristics. Don’t worry, we won’t get lost in heavy technical stuff like electrical power or advanced specs. The idea is to keep it simple and easy to understand, so that when you need a microphone for something specific, you’ll know which one to choose. Think of this post as a warm-up for next week’s content.

Sensitivity, gain, or volume?

It’s easy to confuse these terms, but they’re not the same. Sensitivity is basically a technical measure (written as mV/Pa or dBV/Pa) that shows how much signal a microphone produces when sound hits it. A mic with high sensitivity will catch even soft sounds, while one with low sensitivity needs louder input to work well.

When a microphone captures sound, the signal it produces is usually very weak. Gain is the knob that boosts that signal so you can actually use it. Setting it right is super important: too much gain adds noise and distortion, too little makes your voice sound hidden.

Volume, on the other hand, just controls how loud the final, processed sound is. It doesn’t change the quality of the recording or the strength of the original signal—it only affects what the listener hears. And here’s the key: turning up the volume won’t fix bad gain. If the audio is distorted, it will still sound bad.

To make things crystal clear, let’s break it down:

• Sensitivity isn’t something you tweak—it’s built into the microphone’s design. That’s why choosing the right mic for the right setting (a quiet studio versus a noisy stage) is so important.

• Gain is the adjustment you make while recording. The goal is a clean signal: no saturation, keeping levels in the green or yellow, never in the red. Some microphones even include a dedicated knob to fine‑tune gain before the mixer.

• Volume, on the other hand, is all about playback. It’s shaped by the listener’s taste and the context, whether it’s streaming, a live concert, or a studio session.

Microphone frequency response

This relates to microphone sensitivity, but they are not the same:

Basically, this is how a microphone’s sensitivity changes depending on the pitch of the sound. It shows if the mic plays back all frequencies equally (flat response) or if it boosts or reduces some—for example, making highs brighter or lows deeper.

• Microphone sensitivity: It is an absolute parameter that indicates the voltage level the microphone delivers under a given sound pressure (usually expressed in mV/Pa or dBV/Pa). It is measured at a reference point (e.g., 1 kHz, 94 dB SPL).

• Microphone frequency response: It is the variation of that sensitivity across the audible spectrum. In other words, it describes how the microphone’s output changes depending on the frequency of the incoming sound.

• You’ll usually see it written as a range (like 20 Hz – 20 kHz) and shown in a graph with a curve.

Some examples:

• A studio mic with flat response: captures everything naturally, great for realistic recordings.

• A vocal mic: often boosts mid frequencies (2–5 kHz) to make voices clearer and more present.

• A mic for bass instruments: extends down to lower frequencies (like 40 Hz) to capture kick drums or bass lines better.

Polar pattern

Polar pattern is basically how a microphone “hears” sounds coming from different directions around it. You’ll often see this explained with circular graphs called polar diagrams, which show how sensitive the mic is in every angle. This detail is super important because it tells you what area the mic will pick up clearly and how well it blocks out surrounding noise.

Microphones don’t all “listen” the same way—they use different polar patterns:

• Omnidirectional: hears everything equally from all directions.

• Cardioid: strongest pickup in front, weaker on the sides, and blocks sound from behind.

• Supercardioid / Hypercardioid: even more focused than cardioid, with a narrow front angle and a small rear pickup zone.

• Bidirectional (figure‑8): captures sound from front and back, but rejects the sides.

• Shotgun / Lobar: super narrow and directional, perfect for movies and broadcasting where you need to isolate sound.

Other things you should keep in mind

It refers to the economic value of the microphone in relation to its quality, features, and durability. It is a decisive factor in the choice, since it must balance the available budget with the user’s technical needs. A higher cost is usually associated with greater fidelity of capture and specialized construction, while more affordable options may be sufficient for basic applications. It also relates to the user’s budget, so it can be classified as high or low cost based on an average.

Cost:

Durability:

Durability means how tough a microphone is when used in challenging situations. It covers things like solid construction, resistance to bumps or falls, protection against moisture or dust, and how well its parts hold up over time. This is super important if you’re using the mic a lot—for example, in live concerts, outdoor recordings, or long workdays.

Versatility is basically how flexible a microphone is. A versatile mic might let you switch between polar patterns, keep a balanced sound, and work with different audio setups. That means you can use the same mic for voice, instruments, streaming, or video production without buying more gear. But keep in mind: some microphones are made for very specific jobs, and because of their design, they won’t be useful in every situation.

Versatility:

This first chapter outlined key microphone characteristics—sensitivity, gain, volume, frequency response, polar patterns, cost, durability, and versatility. Understanding these fundamentals is the first step to informed choices. In the next article, we’ll explore practical applications, showing how to select the right mic for studios, live shows, streaming, and more.