We’ve all experienced being struck by a musical idea or a compelling sound but without access to the high-quality audio equipment we’d ideally like to capture it with. It’s all too easy to let a moment of inspiration slip past because we think we don’t have the perfect tool on hand, but thanks to the phones most of us carry around in our pockets, this doesn’t have to be the case. With the ubiquity of smartphones and their constantly improving technologies, we should never have an excuse not to capture a moment of inspiration again.
At Loop 2021, Liz Teutsch, musician, audio engineer and educator, joined us from Jazztone Studios in Valencia, Spain, offering a two-hour deep dive into the basics of microphone technology, and tips on how to make the most of the tools we have available to us. In this workshop, with the assistance of musician and songwriter Gÿe, Liz demonstrated that with a bit of knowledge about the way microphones work, we don’t have to feel stuck without expensive equipment: the microphones in our devices can do more than we might have imagined.
Here we bring you video from Liz’s original workshop at Loop, covering foundational microphone knowledge, a mic comparison with some unexpected results, and some strategies for getting the most out of whatever recording situation you might find yourself in.
What is a Microphone?
To begin the workshop, Liz started us off with some basic microphone knowledge. In the video below, Liz explains how microphones respond to the vibrations of air molecules across the range of human hearing, from 20Hz (frequencies so low that we can feel them more than hear them), to 20,000Hz (frequencies so high generally only young people can hear them). Microphones are our tool for converting these vibrations into electrical energy, and each functions slightly differently, according to their polar (or pickup) pattern, their frequency response, and the microphone type.
Polar (or “pickup”) patterns
The Polar Pattern (also known as the Pickup Pattern) of a microphone is a description of how that microphone responds to a sound in a 3-dimensional space. Some microphones pick up sound 360 degrees around them while others reject sound at certain angles. The three most common types of Polar Patterns are:
Omnidirectional: These microphones pick up sound equally from all directions.
Bi-directional / Figure 8: A bi-directional microphone picks up sound equally from the front and the rear of the microphone, but will reject sounds coming in from the sides.
Cardioid: A Cardioid microphone picks up sounds directly in front of it, but sensitivity is reduced as the sound source moves around to the sides, to a null point directly behind the microphone.
In the video below, Liz and Gÿe demonstrate these three polar patterns, with Gÿe singing while moving around a microphone with a switchable polar pattern. Notice how the sound changes as Gÿe’s position in relation to the mic changes.
If you’re hoping to record multiple sources at once – for example, a group of singers – choosing an omnidirectional microphone will allow you to arrange the group around the microphone. However, in other situations where you want to exclude certain sounds, choosing a directional microphone can help you to reduce bleed in your recordings. By pointing the ‘null point’ of a microphone at a sound source you do not wish to record – which could be anything from another instrument in a band setting to a noisy air conditioner – you can reduce this ‘bleed’, or unwanted sounds.
Frequency Response
Different kinds of microphones respond to the frequency spectrum differently, with certain styles of microphone emphasizing or diminishing certain frequency bands and changing the resulting sound quite dramatically. In the video below, Liz walks us through some basic differences between some common types of microphones, in order to better understand their frequency responses.
Dynamic (or Moving Coil) microphones are very durable and can handle high Sound Pressure Level (SPL), meaning they’re great for live sound applications. They’re most commonly a cardioid polar pattern, meaning that they are directional and will exclude sounds they are not pointed towards. They often have a prominent midrange, and have a limited high frequency response, meaning they don’t capture a lot of high end sparkle.
Ribbon microphones on the other hand are extremely fragile, so are more commonly found in studios than in live sound situations. They most commonly have a Figure 8 / Bidirectional polar pattern, and are described as having a ‘warm’ sound, with a prominent low end and limited high frequency response.
Condenser (or Capacitor) microphones are more durable than Ribbon microphones, but usually require phantom power in order to operate. They capture a lot of detail and clarity, with an extended high frequency response, and can distort or overload at high SPL, so are more common in studio settings.
In the video below, you can see this knowledge in action, as Liz and Gÿe perform a microphone shootout with four different mics; a Dynamic, a Ribbon, a Condenser, and a Smartphone. A microphone comparison like this is commonly done is studio settings, and is especially useful for vocalists, as each voice is so unique that testing multiple options is the best way to determine the optimal microphone to use.
As anticipated, the AKG 414 (a condenser microphone) had a bright, crisp presence, the Coles 4038 (a ribbon mic) had a darker tone, while the Shure SM58 (a dynamic mic) had a noticeable presence in the upper midrange. The sound of the iPhone 7 stood up remarkably well, with a prominence in the 1-2k speaking range, and a hyped high end. Liz also noted that the complete dropoff above 17k means that these mics don’t capture any real upper end sparkle.
The Recording Environment
Regardless of whether you have a selection of the most expensive microphones at your disposal, or if you’re recording your sound with your smartphone, it’s important to know how your recording environment will affect your recordings. In the video below, Liz and Gÿe demonstrate some simple ways that you can take some control over your environment.
Generally speaking, larger rooms tend to have more reverb (a cathedral as opposed to an office, for example), but this isn’t always the case. The number of surfaces in a room, and the reflectiveness of the material of those surfaces, will also have a profound effect on the resonance and ambience of the room. A bathroom, while small, will have many reflective surfaces lending the room a pronounced reverb (as demonstrated in the video below). Liz suggests clapping or singing while listening in a new space, to familiarize yourself with the sonic qualities of the room.
Environmental noise is also an important element to account for when recording with any microphone. While including or featuring some environmental noise in your end result can be a creative choice, sometimes this noise can be less than ideal. A noisy air conditioning unit, or a window out onto a busy street can be mitigated by intelligently using the tools you have; for example, by excluding certain sounds through the use of directional microphones.
You may be happy with your space as it sounds, but sometimes you may want to ‘treat’ the space so it better suits your needs. As demonstrated in the video below, it’s possible to add absorbent material to a reverberant space in order to reduce the resonance of the space. In this video, Liz and Gÿe use a rug and comforter draped over some mic stands to attenuate the pronounced reverb in the studio bathroom, and the difference between the two recordings is striking. Then, by putting Gÿe and the smartphone microphone entirely under a blanket, they demonstrate exactly how to achieve an almost completely dry vocal sound using only the most basic of materials.
Creative Recording
Armed with this knowledge, it’s possible to capture performances and sounds with even the most basic of equipment. Liz and Gÿe took what they’d learned about the microphone in Liz’s smartphone and made a series of recordings in various spaces around the studio. All the audio you will hear in the next video was captured with Liz’s smartphone, with the intention that Gÿe would take the sounds away and incorporate them into one of his upcoming tracks. The end result of this recording session is Gÿe’s latest single ‘MUV’.
With this knowledge in hand, we hope that you’ll never again feel hampered by a lack of expensive recording equipment, and that you’ll feel ready to use whichever microphone you have on hand – even the one in your smartphone – to capture your next idea, wherever you are.