Microphones come with a whole lot of technical and confusing sounding specifications. Ultimately, what matters to people most is how they sound. But not all sounds are created equally, nor are all microphones. Different types of microphones and different specs of the same type of microphone handle certain sounds better than others, and some are just better built.
Understanding those specs can give you some idea of microphone suitability for your video and audio projects before you’ve even heard them, but what do they all mean? In this video, Andrew from Deity talks us through the five most common microphone specs and what they mean.
This is the range of frequencies a microphone can “hear”. Normal human hearing is in the frequency range of 20Hz to 20,000Hz (20KHz). So, we should just get a microphone that does more than that and we’re good. Right? I mean, anything outside of those, we can’t hear anyway. Well, not exactly.
Sometimes, those low sounds can be detrimental to our audio. That’s why some microphones start picking up sound at a relatively high 50Hz or contain a switchable high-pass filter, to help eliminated unwanted bass and rumble that might otherwise be picked up. And microphones that go into much higher frequency ranges are just expensive overkill.
The main thing to understand is where the sound you want to record sits in the frequency spectrum, and that the microphone you’re looking at is capable of picking up that range of frequencies.
These illustrate how the microphone picks up sound coming in different directions. There are all kinds of different patterns like Omni, Figure 8, Cardioid, Hypercardioid, Shotgun and more, which all “hear” sound differently depending on the direction it’s coming from.
Omnidirectional microphones hear everything around them, and each sound source’s loudness is based on their proximity to the microphone. With something like a shotgun mic, it tries to pick out sounds that are dead ahead of where it’s pointing, while blocking out the sounds coming other directions. The others types of pickup pattern sit somewhere in between to suit a range of different circumstances.
The self-noise of a microphone influences two other major factors that are important to know when choosing a microphone. Those are the microphone’s dynamic range (the ratio of the loudest to quietest sounds it can pick up) and the signal-to-noise ratio.
Different types of microphone have different levels of self noise, but typically, the lower the self noise, the wider the dynamic range and the stronger the signal to noise ratio, making for cleaner sounds.
SPL (Sound Pressure Level)
This also contributes to the dynamic range of the microphone. It’s a measure of how much sound it can pick up before it just hears too much and can no longer cope. Basically, with this, the higher the better is often where you want to look, although certain microphone types will be limited. If you use an extremely high SPL dynamic microphone, though, your recorder may start to clip before your microphone does.
This doesn’t directly have anything to do with the microphone’s sensitivity or how good it sounds, it’s all to do with how much power it draws when in use. If you’re using phantom or battery-powered microphones.
Mostly, this is an important spec to know for practical workflow reasons. If you’ve got two high current phantom-powered microphones going into a small handheld recorder, for example, you might end up changing the batteries every half an hour. And you may end up having microphones that try to pull more current than the recorder can even offer.
Listen to them – Not really a spec
The most important factor is just listening to microphones to hear how they sound for yourself. When I was first looking into microphones, more years ago than I care to remember, I took my Tascam DR-100 recorder and BeyerDynamic headphones around the microphone manufacturer stalls with me at what used to be the Broadcast Video Expo so that I could plug in several microphones I was considering and then hear the difference for myself.
This allowed me to immediately discount several microphones that didn’t look bad on paper, but sounded quite awful in my setup. It helped me to spend my money wisely. And I still have and use a couple of those microphones today.
Which microphone spec confuses you the most?