The Microphone Of Tomorrow
Who doesn’t love a bucket?
In the ever-expanding landscape of algorithms and data collection machines, the marketers of today are finding some crazy ways to distinguish and categorize people, products, and even businesses in order to a fit a mold by which they are more easily understood. As we witness the convergence of consumer and professional tools, how can we limit our businesses to a single moniker?
Is Nike an apparel, sportswear, or a media company? Is Microsoft a consumer electronic, software, or enterprise business? Is Hooke Audio a headphone, microphone, or technology company? It seems that software and the cloud have made once separate business markets cohere into one large consumer-driven bucket. Ten years ago, Nike: the technology company, would have seemed a laughing matter, but today they are as steeped in media as Microsoft is in sport accessories.
If the iPhone camera contains over 200 parts, how many parts will be included in the iPhone microphone of tomorrow?
Here is a quick breakdown of the microphone’s core components
A microphone is an acoustic-to-electric transducer or sensor that converts sound into an electrical signal.
FIRST, THE PICKUP PATTERN
A camera has the ability to shoot on a wide angle lens, macro lens, or super focus lens, each of which covers a certain width of visuals. The same goes for audio.
Omnidirectional microphones pick up sound from almost every direction equally. Even the best omni models, however, tend to become directional at higher frequencies, so sound arriving from the back may seem a bit “duller” than sound from the front. The physical size of the omnidirectional microphone has a direct bearing on how well the microphone maintains its omnidirectional characteristics at very high frequencies. If your mic handle is wider than the capsule picking up the sound, you’re going to have some blockage in the audio pickup. That’s why it’s best to have a thin handle to allow the mic capsule to exist unblocked. Like a selfie stick getting into your photo, there will be blockage.
Directional microphones are designed to pick up sound from the front, while tending to reject sound that arrives from other directions. This effect also varies with frequency, and only high quality microphones are able to provide uniform rejection over a wide range of frequencies. Some subtypes of directional mics are:
Cardioid: narrow pick up angle
Subcardioid: even narrower pick up angle
Hypercardioid: SUPER narrow pick up angle
Bidirectional: designed to adequately pick up sound in front and directly behind mic capsule
SECOND, THE TYPE
Arguably there are 9 different types: dynamic, condenser, ribbon, carbon, piezoelectric, fiber optic, laser, liquid, and MEMS. I’ll breakdown the three most popular:
The most popular mic on this planet is a dynamic microphone
1. Dynamic Microphone
Dynamic microphones work using a crazy little thing called electromagnetic induction. When a human or object makes sound, they emit acoustic pressure waves. These acoustic pressure waves are what make microphones tic. In the dynamic microphone’s case, a small movable induction coil positioned in the magnetic field of a permanent magnet is attached to the diaphragm. When acoustic pressure waves enter through the windscreen of the microphone, the sound wave moves the diaphragm. When the diaphragm vibrates, the coil moves in the magnetic field, producing a varying current, this current is what’s sent though cables and eventually amplified.
2. Condenser Microphones
The condenser microphone is sometimes also referred to as a capacitor microphone or electrostatic microphone. In this case, the diaphragm acts as one plate of a capacitor, and the acoustic pressure waves produce changes in the distance between the plates.
Condenser microphones span the range from telephone transmitters through inexpensive karaoke microphones to high-fidelity recording microphones. They generally produce a high-quality audio signal and are now the popular choice in recording studio applications.
Edmund Lowe using a ribbon microphone
3. Ribbon Microphones
Ribbon microphones use a thin metal ribbon suspended in a magnetic field. The ribbon is electrically connected to the microphone’s output. When acoustic pressure waves enter this mic and vibrate the ribbon, the magnetic field generates the electrical signal. Ribbon microphones are similar to moving coil microphones in the sense that both produce sound by means of magnetic induction.
THIRD, THE CONNECTORS
Microphones have an electrical characteristic called impedance, measured in ohms (Ω), that depends on the design of connectors coming out of the microphones.
The output of a given microphone delivers the same power whether it is low or high impedance. If a microphone is made in high and low impedance versions, the high impedance version has a higher output voltage for a given sound pressure input. Most professional microphones are low impedance, about 200 Ω or lower. Professional vacuum-tube sound equipment incorporates a transformer that steps up the impedance of the microphone circuit to the high impedance and voltage needed to drive the input tube.
Low-impedance microphones are more often used because 1) using a high-impedance microphone with a long cable results in high frequency signal loss due to cable capacitance, which forms a low-pass filter with the microphone output impedance, 2) long high-impedance cables tend to pick up more hum (and possibly radio-frequency interference [RFI] as well). Nothing is damaged if the impedance between microphone and other equipment is mismatched; the worst that happens is a reduction in signal or change in frequency response.
2. Digital Microphone Interface
The AES 42 standard, published by the Audio Engineering Society defines a digital interface for microphones. These microphones directly output a digital audio stream through an XLR or XLD male connector. Digital microphones may be used either with new equipment or with appropriate input connections that conform to the AES 42 standard.
FOURTH, THE PROTECTION
Windscreens are used to protect microphones that would otherwise be buffeted by wind or vocal plosives from consonants such as “P”, “B”, etc. Most microphones have an integral windscreen built around the microphone diaphragm.
1. Microphone Covers
Most often made of soft open-cell polyester or polyurethane foam because of the inexpensive, disposable nature of the foam. One disadvantage: covers can deteriorate over time given the flexible material that makes up the cover.
2. Pop Filters
Pop filters or pop screens are used in studio environments to minimize “pops” that the mouth creates when recording. A typical pop filter is composed of one or more layers of acoustically transparent gauze-like material, such as woven nylon. It’s stretched over a circular frame and a flexible mounting bracket to attach to the microphone stand. The pop shield is placed between the vocalist and the microphone.
Blimps (also known as Zeppelins) are large, hollow windscreens used to surround microphones for outdoor location audio, such as nature recording. They can cut wind noise by as much as 25 dB, especially low-frequency noise. The blimp works by creating a volume of still air around the microphone. It’s the ultimate in reduction against wind noise. The microphone is often further isolated from the blimp by an elastic suspension inside the basket. This is great mainly for rattling that may occur when moving the microphone.
The Microphone of Tomorrow
All of the microphone technologies I listed above have existed for decades, yet none of them work universally, affordably and seamlessly with smartphones. How can we expect consumers to care about sound if we don’t give them any control? If we don’t give them any opportunity to experiment with the technologies listed above?
The microphone of tomorrow will be one that works with smartphones, VR headsets, and the internet. And it will do a lot more than just capture sound. It will give you, the consumer, the opportunity to capture your own sound. It will give you professional control at an affordable price. We use so many of the 200 parts in the iPhone camera every day of our lives. Every one of them is essential to getting the perfect shot with relatively little set up. It tells you: “anything’s possible — take that shot.” I want the same for sound. No concert too loud, no memory too quiet, no microphone too complicated or expensive.
The microphone of tomorrow is one that is as accessible, portable, stylish, and affordable as that 200 part camera on your phone. We can do it, and it starts with getting the heck out of mono.
From One Ear To Another,
Hooke Audio Founder