How Are Microphones Made? (Designs, Materials, Production)


Microphones are all around us: in our cellphones and laptops; at live music, broadcast, and presentation venues; and in the mic lockers of those of us who are interested in audio. If you’ve ever wondered how all these microphones are made, this is the article for you!

How are microphones made? Different microphone manufacturers produce their microphones differently. Some design and produce everything in-house while others outsource. Some do everything by hand while others use machines. Through all the differences, though, mics of a given type have the same basic design.

Though it would take ages to describe how each model of microphone is made, this article will go as in-depth as possible about the general designs, materials, and production techniques used to make microphones.


The Components That Make A Microphone

Before we get into the specific designs of specific microphone types, let’s describe the critical components that make up microphones.

Diaphragm

The diaphragm is the most important component of a microphone. In fact, all microphone types (except for the experimental laser microphone) have a diaphragm.

A microphone diaphragm is a thin membrane that moves according the sound waves (sound pressure variance) it experiences. The diaphragm movement basically mimics the sound waves, which allows the microphone to effectively recreate sound as an audio signal.

For more information on microphone diaphragms, check out the following My New Microphone articles:
What Is A Microphone Diaphragm?

What Are Microphone Diaphragms Made Of? (All Diaphragm Types)

Capsule/ Cartridge/ Baffle

A diaphragm, by itself, is no good for anything. It needs to be housed within a body that allows for energy conversion.

Depending on the microphone type, there are different words to describe this housing. Note that the term “capsule” is often applied to any mic diaphragm housing, though “capsule” typically means a condenser’s transducer component.

Moving-coil dynamic microphones have cartridges. The circular diaphragm is tensioned around a ring within the cartridge and a conductive coil is attached to the back side of the diaphragm. The coil sits in a cylindrical cut-out within a magnet.

Shure SM58 Cartridge

As the diaphragm and coil move in accordance to sound pressure, a coinciding audio signal is created across the conductive coil via electromagnetic induction.

Ribbon dynamic microphones have baffles or elements. The long corrugated rectangular ribbon is tensioned and held at each end of its length. The ribbon is made of conductive material and sits within a magnetic perimeter.

Royer R-121
Ribbon Baffle/Element

As the conductive diaphragm moves in accordance to sound pressure, a coinciding audio signal is created across the ribbon diaphragm via electromagnetic induction.

Condenser microphones utilize more complicated capsules. The diaphragm is tensioned around a ring and acts as a movable front plate of a parallel-plate capacitor.

Neumann K67 Capsule

This capacitor sits within the housing of the capsule and requires a fixed charge (supplied externally via powering methods or permanently via electret material).

With a fixed charge, any variation in the distance between the plates (as the diaphragm moves) causes an inversely proportionate change in voltage across the plates. This AC voltage is the first stage of the mic signal.

For a detailed read on microphone capsules, cartridges, and baffles, check out my article What Is A Microphone Capsule? (Plus Top 3 Most Popular Capsules).

Transistor

Though transistors are required in analog-to-digital converter and are sometimes used in the printed circuit boards of microphones, when we discuss the transistor of a microphone, we are typically referring to either:

  • Field-effect transistor (FET).
  • Junction-gate field-effect transistor (JFET).

Both of of these field-effect transistors act as impedance converters (and amplifiers) of the microphone signal. Generally, these FETs/JFETs are positioned immediately after a condenser capsule.

The output signal of a condenser capsule has an incredibly high impedance and is not able to travel though the mic circuitry without degradation. Dropping the impedance is critical.

The transistor’s gate (input) as a high load impedance and easily accepts the capsule’s output signal.

A biasing voltage (from a DC bias voltage, phantom power, USB power, or an external power supply) provides power to the FET/JFET.

The gate signal (from the mic capsule) modulates the current of signal provided by the external powering. The modulated signal has much lower impedance and will likely have a greater voltage.

Transformer

Transformers are commonly placed just before the output of a microphone Though they may be placed in other parts as well, like before the tube of a rube ribbon mic. They are passive devices that provide impedance conversion; voltage increasing or decreasing; DC protection; and sometimes saturation (colouration).

A simple transformer is made of a magnetic core and two winding: the primary winding, which connects within the microphone transducer circuit (or at least toward the transducer circuit), and the secondary winding, which makes up the microphone output circuit.

These windings are made of conductive wire and are largely defined by the amount of times they wind around the magnetic core (referred to as the “number of turns”). The conductive windings do not physically touch one another and are therefore not electrical connected, though certainly connected via magnetic induction.

Shure 51A303 Step-Up Transformer

There are two general types of microphone transformers:

  • Step-up transformer (fewer turns in primary winding, more turns in secondary winding): Step-up transformers increase the voltage while increasing the impedance of the mic signal (from primary to secondary). These transformers are used in passive dynamic mics that naturally output low voltages that can handle the increase in impedance.
  • Step-down transformer (more turns in primary winding, fewer turns in secondary winding): Step-down transformers decrease the voltage while decreasing the impedance of the mic signal (from primary to secondary). These transformers are typically used in active mic outputs to drop the impedance to professional levels. Active mic signals generally have strong voltages and can handle the decrease in voltage through the step-down transformer.

Change in voltage (secondary/primary) = turns ratio (secondary/primary).

Change in voltage (secondary/primary) = square of turns ratio (secondary/primary).

For more information on microphone transistors and transformers, check out my article Do All Microphones Have Transformers And Transistors? (+ Mic Examples).

Vacuum Tube

Vacuum tubes are responsible for the same job as the aforementioned transistors. In fact, vacuum tubes were necessary for impedance conversion and “amplification” in condenser microphones before the invention of the transistor in 1947 (though the first FET microphone only came to be in 1964: the Schoeps CMT 20).

The simplest microphone vacuum tube is a triode. Triodes have the following components within their tubes:

  • Heater.
  • Cathode.
  • Anode.
  • Grid.
Electro-Harmonix
6072A 12AY7EH Vacuum Tube

An external power supply is required to power the heater and heat up the vacuum tube.

With sufficient heat, electrons being to flow from the cathode to the anode.

An alternating electrical current, in this case the signal from the mic capsule is applied to the grid of the tube. This grid signal then modulates the flow of electrons from the cathode to the anode (the tube’s output audio signal).

The grid input can accept the high-impedance signal from the capsule. The tube’s output signal has much lower impedance and most often has a stronger voltage (note that this is not true amplification).

Printed Circuit Board

Printed circuit boards are commonly used in active microphones.

Their circuits include:

  • Amplifiers.
  • Passive attenuation devices.
  • Filters.
  • Switches.
Rode NT1 Printed Circuit Board

Body

The body of the microphone holds the entire unit together and provides protection to the inner components of the microphone.

Although bodies are not necessary for the functionality of a microphone transducer, they are critical mic longevity and usage.

Shure SM57 Body/Outer Casing

Grille

The microphone grille could technically be referred to as part of the mic body.

This perforated material protects the mic diaphragm and capsule (or cartridge or baffle) while still allowing sound waves to pass through and interact with the diaphragm.

Neumann U 87 Ai Grille

For more information on microphone grilles, check out my article What Are Microphone Grilles And Why Are They Important?

Output Connector

In order for a microphone to output its signal and send its anywhere, it needs an output connector.

Most professional microphones use XLR-type output connectors. However, there are plenty of mic output connectors on the market:

  • XLR (3-pin, 5-pin, 7-pin, or other variant).
  • TS (2.5mm, 3.5mm (1/8″), or 1/4″).
  • TRS (2.5mm, 3.5mm (1/8″), or 1/4″).
  • TRRS (2.5mm, 3.5mm (1/8″), or 1/4″).
  • RCA.
  • TA3 (mini-XLR).
  • TA5.
  • Tube Power Supply connector.
  • 2501F.
  • Nexus.
  • CB.
  • Tuchel.
Rode NT1-A
XLRM Output Connector

For an in-depth guide on microphone output connectors, check out the following My New Microphone articles:

What Do Microphones Plug Into? (Full List Of Mic Connections).
Why Do Microphones Use XLR Cables?


Basic Designs And Common Materials

Now that we understand the basics of the key components of microphones, let’s get into the designs and materials used to construct the main microphone types.

In this section, we’ll discuss the basic design principles and the materials used in the follow mic types:

Though I go into detail here, I discuss how each microphone types function in greater detail in my article How Do Microphones Work? (A Helpful Illustrated Guide).

Moving-Coil Dynamic Mic

Heil PR40 Moving-Coil Dynamic Mic

Heil Sound is featured in My New Microphone’s Top 11 Best Microphone Brands You’ve Likely Never Heard Of.

The basic design of a moving-coil dynamic microphone involves the following:

  • Diaphragm with conductive coil attached. The diaphragm is typically made of polyester film (Mylar is a common brand) while the conductive coil is typically copper.
  • Magnets and pole pieces. The magnets are often made from high-quality rare earth Neodymium or ferrite. The pole pieces can be made from the same material or soft iron (in order to create the odd magnet shape).
  • Cartridge housing (including rear ports if applicable). The cartridge housing is typically made from non-conductive material like hard plastic and non-magnetic metals. There is also typically acoustic foam within the housing (most often polyurethane).
  • Lead wires. Like most electrical wiring, the microphone lead wires are insulated copper strands.
  • Output step-up transformer (if applicable). Transformers are made from conductive coil windings (copper) wound around a magnetic core (ferrite/iron).
  • Output connector. Generally made with gold- or silver-plated contacts.
  • Body. The body/case material is often made from durable non-magnetic steel or stainless steel.
  • Grille/cap. Made from a metal mesh “wire-cloth” (brass and steel are common. Iron has been used in older mics).
The Basic Flow Of Energy Through A Moving-Coil Dynamic
Moving-Coil Dynamic Microphone Transducer

The basic transducer design of a moving-coil dynamic microphone has a diaphragm with an attached conductive coil. This coil sits in a cylindrical cutaway within a magnet with the one magnetic pole to its interior and the other magnetic pole to its exterior.

As the diaphragm moves according to sound pressure, so too does the attached coil (hence the name “moving-coil”). As the coil moves within the permanent magnetic field, it experiences a changing magnetic flux and a voltage (mic signal) is induced across it via electromagnetic induction.

Step-Up Transformer
Primary Winding To The Left
Secondary Winding To The Right

The relatively weak AC signal from the moving-coil is typically sent to the primary winding of the step-up transformer.

The AC voltage in the primary winding causes a changing magnetic flux within the magnetic core of the transformer. This changing flux then induces a larger voltage across the secondary winding, since the secondary has more turns than the primary.

The “output” of the transformer (the voltage across the secondary winding) is carried to the microphone output.

For more information on the moving-coil dynamic microphone design, check out my article Moving-Coil Dynamic Microphones: The In-Depth Guide.

Ribbon Dynamic Mic

AEA R44CE Ribbon Dynamic Mic

AEA is featured in My New Microphone’s Top 11 Best Microphone Brands You’ve Likely Never Heard Of.

The basic design of a ribbon dynamic microphone involves the following:

  • Conductive ribbon-like diaphragm. Ribbon diaphragms are most often made of a thin corrugated aluminum ribbon. Some ribbons are coated with gold to prevent oxidation. Some other ribbons are made of strong plastic polymers coated with aluminum.
  • Magnets and pole pieces. The magnets are typically made of ferrite or powerful neodymium. The pole pieces require high magnetic permeability are often made of soft iron or alloys such as Permendur and Hyperco 90.
  • Baffle/element housing. The baffle is made up mostly by the magnets and pole piece. The entire housing is often held together with steel or hard plastic.
  • Lead wires. Like most electrical wiring, the microphone lead wires are insulated copper strands.
  • Output step-up transformer (if applicable). Transformers are made from conductive coil windings (copper) wound around a magnetic core (ferrite/iron).
  • Output connector. Generally made with gold- or silver-plated contacts.
  • Body. The body/case material is often made from durable non-magnetic steel or stainless steel.
  • Grille/cap. Made from a metal mesh “wire-cloth” (brass and steel are common. Iron has been used in older mics).
The Basic Flow Of Energy Through A Passive Ribbon Dynamic
Ribbon Dynamic Microphone Transducer

The basic transducer design of a ribbon dynamic microphone has a conductive ribbon-like diaphragm with an attached conductive coil. This diaphragm is attached at each end of its length and sits within a magnet with the one magnetic pole to its left and the other magnetic pole to its right.

As the diaphragm moves according to sound pressure, it experiences a changing magnetic flux and a voltage (mic signal) is induced across it via electromagnetic induction.

The relatively weak signal (typically even weaker than a moving-coil dynamic signal) is always sent through a step-up transformer (discussed above) in order to increase the voltage, and therefore the strength of the mic signal.

The Basic Flow Of Energy Through An Active Ribbon Dynamic

There are some active ribbon microphones on the market that benefit from internal amplifiers (whether solid state or tube). Though these are not your typical ribbons.

The amplifying components work basically the same as in our other active microphones, which we’ll get to next.

For more information on the ribbon dynamic microphone design, check out my article Dynamic Ribbon Microphones: The In-Depth Guide.

Electret Condenser Mic

Rode NT1-A Electret Condenser Mic

Rode is featured in My New Microphone’s Top 11 Best Microphone Brands You Should Know And Use.

The basic design of an electret condenser microphone involves the following:

  • Diaphragm (front plate) with electret material and/or conductive material attached. This is one plate of the parallel plate capacitor capsule. The diaphragm is most often made of thinly stretched polyester film (Mylar is a common brand) with a conductive material on the surface (see gold sputtering). Older mics sometimes include extremely thin metal foil on top of their diaphragms (which were made from Stryoflex plastic, PVC, and other materials).
  • Backplate (with electret material and/or conductive material attached if it isn’t attached to the diaphragm). This is the other plate of the parallel plate capacitor capsule. The backplate is often made of solid brass.
  • Electret film: The electret material is typically quasi-permanently charged Polytetrafluoroethylene (Teflon is a common brand)
  • Conductive material: The conductive material of the capsule is typically in the form of gold sputtering on the diaphragm
  • Capsule housing (including rear ports if applicable). The capsule housing is put together with plastic and brass tensioning rings, insulating rings (often made of teflon), and metal screws.
  • Lead wires. Like most electrical wiring, the microphone lead wires are insulated copper strands.
  • Impedance converter (FET or JFET). The FET/JFET impedance converters are made like other transistors: with semi-conductive material (typically silicon) within a case.
  • Printed circuit board (if applicable). A PCB uses one or more copper sheets laminated onto and/or between non-conductive sheets. Electrical components (resistors, capacitors, amps, etc.) are mechanically supported and electrically connected in the PCB.
  • Output connector. Generally made with gold- or silver-plated contacts.
  • Body. The body/case material is often made from durable non-magnetic steel or stainless steel. Electret mics are often used in larger electronic devices that simply feature a microphone. In this case, the “microphone body” would be the body of the larger device.
  • Grille/cap. Made from a metal mesh “wire-cloth” (brass and steel are common. Iron has been used in older mics). Sometimes this grille/cap is non obvious, hidden, or non-existent (like with laptops and smartphones).
The Basic Flow Of Energy Through An Electret Condenser
Condenser Microphone Transducer

All condenser microphones work on electrostatic principles. I’ll describe them quickly here, beginning with equations.

V = Q / C

Voltage (V), which is our mic signal, is equal to the charge (Q) divided by the capacitance (C) of the parallel-plate capacitor.

The charge (Q) is fixed. In electret mics, the capsule is permanently charged by electret material. In non-electret mics, an external power source (phantom power of a PSU) supplies the fixed charge.

Therefore, to create a voltage (V) or mic signal, we need to alter the capacitance C. This will cause an inversely proportionate change in voltage (mic signal).

C = ε0(A / d)

The Capacitance (C) of the parallel-plate capacitor is equal to the electric constant (ε0) times the area of the plates (A) divided by the distance (D) between the plates.

The electric constant (ε0) is constant, as is the area of the plates (A). It is the distance between the plates that may vary the capacitance.

So varying the distance between the plates changes the capacitance which causes a voltage (mic signal) across the plates. This is the basis of all condenser microphone capsules.

As the diaphragm (front plate) moves, a mic signal is produced across the plates and taken away via electrical leads.

This signal, like all condenser capsule out signal, has very high impedance and requires an impedance converter if it is to be properly outputted from the mic. In electret mics, a JFET is typically used for this job.

Basic Picture Of An FET/JFET

Without getting into too much detail (this article is getting long), the capsule output is sent to the gate (G) of the JFET. The gate acts to modulate the current between the source (S) and drain (D), which is provided via external voltage (DC bias, phantom power).

The gate has a high input impedance and can accept the capsule’s signal. It outputs a signal (that is modulated by the gate) at a much lower impedance and greater voltage.

This signal, after running through a printed circuit board (if there is one) is outputted from the mic.

Electret Microphones Within Other Devices

Consumer Electret Mic

Note that electret condenser microphones are the most common type of microphone in the world. We don’t only find electret capsules in studio mics and lavaliers. We find them in consumer electronics, cell phones, hearing aids, laptops, etc.

When designed into other electronics, electret mics obviously do not require an outer standalone shell of a body.

However, there is still need for the capsule (diaphragm, backplate, housing), the lead wires, the impedance converting FET or JFET, and a grille/cap.

The mics is still likely connected to a printed circuit board and/or analog-to-digital converter. These components are arguably part of the electronic device and simply have the microphone feed audio into them.

True FET Condenser Mic

Neumann KM 184 True FET Condenser Mic

Neumann is featured in My New Microphone’s Top 11 Best Microphone Brands You Should Know And Use.

The basic design of a true FET condenser microphone involves the following:

  • Diaphragm (front plate) with electret material and/or conductive material attached. This is one plate of the parallel plate capacitor capsule. The diaphragm is most often made of thinly stretched polyester film (Mylar is a common brand) with a conductive material on the surface (see gold sputtering). Older mics sometimes include extremely thin metal foil on top of their diaphragms (which were made from Stryoflex plastic, PVC, and other materials).
  • Backplate (with electret material and/or conductive material attached if it isn’t attached to the diaphragm). This is the other plate of the parallel plate capacitor capsule. The backplate is often made of solid brass.
  • Conductive material: The conductive material of the capsule is typically in the form of gold sputtering on the diaphragm
  • Capsule housing (including rear ports if applicable). The capsule housing is put together with plastic and brass tensioning rings, insulating rings (often made of teflon), and metal screws.
  • Lead wires. Like most electrical wiring, the microphone lead wires are insulated copper strands.
  • Impedance converter (FET or JFET). The FET/JFET impedance converters are made like other transistors: with semi-conductive material (typically silicon) within a case.
  • Printed circuit board (if applicable). A PCB uses one or more copper sheets laminated onto and/or between non-conductive sheets. Electrical components (resistors, capacitors, amps, etc.) are mechanically supported and electrically connected in the PCB.
  • Output step-down transformer (if applicable). Transformers are made from conductive coil windings (copper) wound around a magnetic core (ferrite/iron).
  • Output connector. Generally made with gold- or silver-plated contacts.
  • Body. The body/case material is often made from durable non-magnetic steel or stainless steel.
  • Grille/cap. Made from a metal mesh “wire-cloth” (brass and steel are common. Iron has been used in older mics).
The Basic Flow Of Energy Through A Transformerless True FET Condenser
The Basic Flow Of Energy Through A True FET Condenser With An Output Transformer

Unlike the previously mentioned electret capsule, the true condenser capsule requires an external voltage to polarize its parallel-plate capacitor. Other than that, the capsules work basically the same and require the same kind of FET/JFET impedance converter for their output signal.

From there, the mics signal may run through a printed circuit board.

Step-Down Transformer
Primary Winding To The Left
Secondary Winding To The Right

Many true condensers (particularly older models) use step-down transformers at their outputs.

Although these transformers reduce the voltage of the signal at their outputs (secondary windings), the benefit of impedance adjustment is well worth it.

Note that in transformerless microphones, the output is adjusted via solid state circuitry rather than a transformer.

Tube Condenser Mic

AKG C 12 VR Tube Condenser Mic

AKG is featured in My New Microphone’s Top 11 Best Microphone Brands You Should Know And Use.

The basic design of a tube condenser microphone involves the following:

  • Diaphragm (front plate) with electret material and/or conductive material attached. This is one plate of the parallel plate capacitor capsule. The diaphragm is most often made of thinly stretched polyester film (Mylar is a common brand) with a conductive material on the surface (see gold sputtering). Older mics sometimes include extremely thin metal foil on top of their diaphragms (which were made from Stryoflex plastic, PVC, and other materials).
  • Backplate (with electret material and/or conductive material attached if it isn’t attached to the diaphragm). This is the other plate of the parallel plate capacitor capsule. The backplate is often made of solid brass.
  • Conductive material: The conductive material of the capsule is typically in the form of gold sputtering on the diaphragm
  • Capsule housing (including rear ports if applicable). The capsule housing is put together with plastic and brass tensioning rings, insulating rings (often made of teflon), and metal screws.
  • Lead wires. Like most electrical wiring, the microphone lead wires are insulated copper strands.
  • Vacuum Tube. The vast majority or tubes have glass envelops (though some are made of ceramic or metal). Tubes have glass-to-metal seals based on borosilicate glasses. The triode is the basic microphone tube and is built with a heater; cathode; anode; and grid (all of which are made from metal).
  • Printed circuit board (if applicable). A PCB uses one or more copper sheets laminated onto and/or between non-conductive sheets. Electrical components (resistors, capacitors, amps, etc.) are mechanically supported and electrically connected in the PCB.
  • Output step-down transformer (if applicable). Transformers are made from conductive coil windings (copper) wound around a magnetic core (ferrite/iron).
  • Output connector. Generally made with gold- or silver-plated contacts.
  • Body. The body/case material is often made from durable non-magnetic steel or stainless steel.
  • Grille/cap. Made from a metal mesh “wire-cloth” (brass and steel are common. Iron has been used in older mics).
  • External power supply unit. An external power supply unit is required to heat the tubes in tube microphones (they also polarize the capsule). PSUs convert the AC power mains to the DC voltage the mic needs. They do so with transformers, capacitors, and other electric devices.

Tube microphones are typical of the externally-polarized condenser type (though there are some tube ribbon microphones on the market).

Royer R-122V Tube Ribbon Mic

Royer is featured in My New Microphone’s Top 11 Best Microphone Brands You Should Know And Use.

The capsule works the same as any other externally polarized capsule except it gets its polarizing voltage from an external power supply rather than phantom power. Phantom power is not strong enough to run a tube microphone (particularly due to heating the vacuum tube).

Basic Triode Vacuum Tube Diagram

The high-impedance output signal from the capsule requires an impedance converter. This is where the tube comes in.

The tube (pictured above) has a heater (H), which takes power from the PSU and heats the tube up. The cathode (K), once heated, starts emitting electrons, which flow to the anode (A).

The capsule signal is connected to the grid (G). The AC signal alters the gate, which in turn modulates the electron flow from the cathode to anode.

The “tube input” at the grid takes in the high-impedance capsule signal and uses it to modulate a lower-impedance and higher-voltage “tube output” signal at the anode.

This tube output is then sent to an output step-down transformer than effectively adjusts the impedance of the output signal while also balancing it for effective transmission.

Lavalier Mic

Sennheiser MKE2 Lavalier Mic

Sennheiser is featured in My New Microphone’s Top 11 Best Microphone Brands You Should Know And Use.

The basic design of a lavalier microphone involves the following:

  • Electret condenser capsule or moving-coil dynamic cartridge. These capsules/cartridges are designed in the same way as the aforementioned electret capsules or moving-coil dynamic cartridge, but much smaller.
  • Housing (including rear ports if applicable). The housing is also designed the same, only smaller.
  • Impedance converter JFET (if electret). These JFETs are made with semi-conductive material (often doped silicon).
  • Lead wire(s) and cable. Lavaliers generally have a cable attached to the microphone. This cable has one or more signal wires (insulted copper) and a shield/ground wire (also copper). The cable is also insulated.
  • Output connector. The output connector of lav mics are sometimes XLR and sometimes not. Regardless, they are most often either solid brass or plated with gold or silver.
  • Body. The body is also small and typically made of hard plastic or metal.
  • Grille/cap. The small cap/grille is often removable and can greatly alter the frequency response of the mic capsule.

These small microphones typically come with clips to attach to clothing. They also typically connect to a wireless transmitter.

For a related read on lavalier microphones, check out my article How And Where To Attach A Lavalier/Lapel Microphone.

Shotgun Mic

Schoeps CMIT5 U Shotgun Mic

Schoeps is featured in My New Microphone’s Top 11 Best Microphone Brands You Should Know And Use.

The basic design of a shotgun microphone involves the following:

  • Condenser capsule (electret or true) or moving-coil dynamic cartridge. Condenser microphones can have condenser capsules or moving-coil dynamic cartridges.
  • Capsule/cartridge housing. As with any microphone, these capsules/cartridges sit within the body of the mic in proper housing.
  • Lead wires. The microphone lead wires are insulated copper strands.
  • Impedance converter FET or JFET (if condenser). These transistors are made with semi-conductive material (often doped silicon).
  • Printed circuit board (if applicable). A PCB uses one or more copper sheets laminated onto and/or between non-conductive sheets. Electrical components (resistors, capacitors, amps, etc.) are mechanically supported and electrically connected in the PCB.
  • Output step-down transformer (if applicable). Transformers are made from conductive coil windings (copper) wound around a magnetic core (ferrite/iron).
  • Output connector. Generally made with gold- or silver-plated contacts.
  • Body. The body/case material is often made from durable non-magnetic steel or stainless steel.
  • Interference tube. The interference tube extends the body outward from the front of the diaphragm. It is typically made from the same material as the body and has slits along its length with perforated mesh which allows sound to enter.
  • Grille/cap. Made from a metal mesh “wire-cloth” (brass and steel are common. Iron has been used in older mics).

The interference tube of these microphones make them very long and narrow. Various ports in the tube cancel out various sound frequencies that reach the mic from different angles. By cancelling these sound waves before they reach the diaphragm, a high directional “shotgun” polar pattern is achieved.

For more information on shotgun microphones, check out my article The Lobar/Shotgun Microphone Polar Pattern (With Mic Examples).

USB Mic

Blue Yeti USB Mic

Blue is featured in My New Microphone’s Top 11 Best Microphone Brands You Should Know And Use.

The basic design of a USB microphone involves the following:

  • Condenser capsule (electret or true), moving-coil dynamic cartridge, or ribbon baffle/element. USB microphones can have any type of capsule.
  • Capsule/cartridge/ribbon housing. These capsules are held within the proper housing.
  • Lead wires. The microphone lead wires are insulated copper strands.
  • Impedance converter FET or JFET (if condenser). These transistors are made with semi-conductive material (often doped silicon).
  • Printed circuit board (if applicable). A PCB uses one or more copper sheets laminated onto and/or between non-conductive sheets. Electrical components (resistors, capacitors, amps, etc.) are mechanically supported and electrically connected in the PCB.
  • Analog-to-digital converter. ADCs are implemented as integrated circuits, which uses electrical circuits and many transistors on a “chip” of semiconductor material (most often silicon).
  • Audio interface. The USB mic acts as an audio interface with digital ins (from computer) and outs (from mic) as well as analog ins (from mic transducer) and outs (from interface to headphone amp).
  • Headphone amp (if applicable). The headphone amp is made of its own amplifier circuits, which hosts amps, transistors, and other electrical components.
  • Output connector. The output connector is a digital USB port. The connections are typically made of brass (copper /zinc alloy) plated with nickel or sometimes gold.
  • Body. The body/case material is often made from durable non-magnetic steel or stainless steel.
  • Grille/cap. Made from a metal mesh “wire-cloth” (brass and steel are common. Iron has been used in older mics).

To read more about USB mics (and digital mics in general), check out the following My New Microphone articles:
How Do USB Microphones Work And How To Use Them
Are Microphones Analog Or Digital Devices? (Mic Output Designs)

In-House Vs. Outsourcing

Some microphones are designed and produced completely in-house while others have most of their parts brought in from other manufacturing companies.

As is the case with most manufacturing, Chinese and other Asian-made microphone components can be purchased at a fraction of the cost (and effort) or producing these components in house. These components are often inexpensive clones and work perfectly well.

The other case for outsourcing is to purchase a microphone component that is better than what the mic manufacturer could design and produce in-house.

Commonly outsourced microphone components include:

  • Capsules (AKG CK12 and Neumann K47 and K67 clones are commonly outsourced for microphones). Thiersch is another common capsule brand.
  • Tubes (common brands include Hiller, Telefunken, General Electric. Electro Harmonix, Joint Army Navy (JAN), Sovtek).
  • Transformers (common brands include Jensen, TAB-Funkenwerk, Haufe, HAHN).

The main benefits of producing the microphone components in-house is quality assurance and the ability to design the components to work exactly how the manufacturer wants them to within the mic design.

This, of course, increases costs in labour, design, and materials, but will often produce a better microphone design.

By Hand Vs. Machines

Some manufacturers assemble their high-end microphones by hand to ensure quality.

Other manufacturers that sell large quantities of microphones at lower price points used machines in the assembly of their microphones. This helps to reduce labour costs and keep the microphone prices low.

That being said, machines are certainly used to help those “hand-built” microphone manufacturers. For example, individual components like the microphone body, grille, capsule, etc. benefit from the high precision of machines.

Once machine-built to spec, though, these components are assembled together by hand, which is very delicate work.

Some “built-by-hand” manufacturers include:

  • Neumann.
  • AKG.
  • Royer.
  • Bock Audio.
  • Cascade.
  • Peluso.
  • sE Electronics.
  • Soyuz.
  • Chandler Limited.
  • Applied Microphone Technology.
  • Many other boutique microphone manufacturers.

For more information on the brand above, check out my article Full List Of Microphone Manufacturers.

To read about the best mic brands in the world (in my opinion), check out the following My New Microphone articles:
Top 11 Best Microphone Brands You Should Know And Use
.
Top 11 Best Microphone Brands You’ve Likely Never Heard Of
.


How was the microphone invented? Though controversial, History tells us the first microphone was invented by Alexander Graham Bell and was developed for use with the telephone. The microphone was originally made of a diaphragm; wire; liquid transmitter (acid); brass rod; battery; and secondary wire and diaphragm (the speaker).

For a deeper read into the invention and reinventions of microphones, check out my article Who Invented The Microphone And Who Invented Each Mic Type?

Why are microphones called microphones? The term ‘microphone’ can be broken into ‘micro’ and ‘phone.’ Micro (from Greek mikros) means “small” and phone (from Greek phone) means “sound” or “voice.” Microphone translates to “small sound,” which is accurate, as the microphone deals with small audio signals.

For an in-depth explanation of the term microphone, check out the following My New Microphone articles:

Why Are Microphones Called Microphones?
What Is A Microphone? (Mic Types, Examples, And Pictures).

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