The vast majority of microphones are either dynamic or condenser mics. These classifications are widely used to differentiate between transducer types, but they also give us a general sense of how the microphone will perform.
What are the differences between dynamic and condenser microphones? The main difference between dynamic and condenser mics is that dynamics convert sound to audio via electromagnetic induction while condensers do so via electrostatic principles. This leads to differences in design and overall sound. Condensers are active, while dynamics are usually passive.
This is only a brief response to a much deeper question. In this article, we'll dive deeper into answering this question and discuss all the general differences between dynamic and condenser microphones.
Dynamic Vs. Condenser Microphones
Tables are an easy way to disseminate information. Let's look at the differences between dynamic and condenser mics in the following table:
|All but bidirectional
|All (especially with dual-diaphragm capsule)
|Maximum Sound Pressure Level
|Often too high to measure
|Often within practical limits
|Inexpensive to moderate
|Cheap to very expensive
To read more about moving-coil dynamic microphones, check out my article Moving-Coil Dynamic Microphones: The In-Depth Guide.
Similarities Between Dynamic And Condenser Microphones
Let's start with the obvious and talk about dynamic and condenser mics both being microphones. That is to say that they are transducers of energy that convert sound (mechanical wave energy) into audio (electrical energy). Both microphones do so with a diaphragm.
Besides mic-specific commonalities in application, polar pattern, address type, and small details, dynamic and condenser microphones have very few similarities. Let's talk about the differences.
Perhaps the most obvious difference between dynamic and condenser microphones is the difference in transducer principles.
Dynamic microphones convert energy via electromagnetic induction, while condenser microphones do so with electrostatic principles.
Dynamic microphones work on electromagnetic induction.
Electromagnetic induction is defined as the production of a voltage across an electrical conductor as that conductor experiences a changing magnetic field.
Here is a simplified diagram of a moving-coil dynamic transducer element:
Dynamic microphones (more technically referred to as “moving-coil dynamic microphones”) have a conductive coil attached to the rear side of their diaphragms. This coil is typically made of copper.
The diaphragm and moving coil are part of the mic capsule or “cartridge” and sit within a permanent magnetic field. This magnetic field is provided by magnets and pole pieces designed to host the coil in a cylindrical cutaway.
So as the diaphragm moves, so too does the conductive coil. As the coil oscillates within the magnetic structure, it experiences this field differently. This changing magnetic field relative to the moving coil causes a voltage to be induced across the coil.
As the diaphragm and coil move back and forth about their resting position, a coinciding AC voltage (microphone signal) is created.
Condenser microphones work on electrostatic principles.
Simply put, a condenser microphone capsule acts as a parallel-plate capacitor.
Here is a simplified diagram of a condenser microphone transducer element:
This capacitor is made up of a movable front plate (the diaphragm) and a stationary backplate. To function properly, the capacitor must hold a fixed charge. This charge can be supplied via electret material, DC bias voltage, phantom power, or an external power supply.
With a fixed charge, any change in capacitance causes an inversely proportional change in voltage. Fortunately, the distance between the two plates is a factor in the capacitance of the condenser capsule.
Therefore, as the diaphragm moves with the sound waves around it, it alters the distance between the plates and causes a coincidental change in the capacitance of the capsule. This alternating capacitance causes an inversely proportionate AC voltage (mic signal) to be created across the capacitor.
All condenser microphones require power to function properly and are, therefore, active. Dynamic microphones are passive and do not require power to function.
Condenser microphones are always active.
All condenser microphones have component(s) that require power to function properly. These components are as follows:
- Vacuum tubes: vacuum tube electronics act as impedance converters and pseudo-amplifiers in tube condenser mics. These tube are most often triodes and require an external power supply to be heated properly.
- Impedance converters: non-tube impedance converters are made from solid-state field-effect transistors, which require less power than tubes, but need power nonetheless. Depending on the mic, this power can be supplied by various methods (electret material, DC bias voltage, phantom power).
- Capsules: “true” condenser microphones require external power to properly charge their capsules. Electret condensers have a quasi-permanent charge on their capsules via electret material.
- Printed circuit boards: PCBs encompass the main circuitry of a microphone. Some condenser microphones have PCBs and some PCBs require power in order run their active components (like amplifiers).
Dynamic microphones are nearly always passive.
Dynamic mics work on electromagnetic induction, which requires no power.
Even output transformers, which are common enough in dynamic mics, are passive and require no power.
The caveat here is in dynamic digital/USB microphones. In these special cases, the internal analog-to-digital convert (and in some cases the headphone amp) do require power to function, making these dynamic mics active.
The Rode Podcaster is featured in the following My New Microphone articles:
• Top 20 Best Microphones For Podcasting (All Budgets)
• Top 9 Best USB Microphones (Streaming, PC Audio, Etc.)
To learn more about transistors and transformers, check out my article Do All Microphones Have Transformers And Transistors? (+ Mic Examples).
For a full article on the differences between active and passive microphones, check out my article Do Microphones Need Power To Function Properly?
Typically, dynamic microphones have limited and coloured frequency responses, while condenser microphones have very accurate but sterile-sounding frequency responses.
Condenser microphones have relatively flat and extended frequency responses.
Most condenser microphones will have a fairly flat frequency response across the audible spectrum (20 Hz – 20,000 Hz). In other words, they're capable of recreating sound as audio very accurately.
Large-diaphragm condensers will often have a slight boost in the high-frequency range followed by a slight roll-off at the top end of their frequency response. This helps to add presence to the mic signal but may also cause the mic to sound harsh.
Small-diaphragm condensers benefit from extended frequency responses (sometimes well above the audible spectrum) and a flatter high-end frequency response.
It's also worth noting that condenser mic diaphragms are often tuned so that their natural resonant frequencies are diminished in their frequency response.
Dynamic microphones have relatively limited and coloured frequency responses.
All dynamic microphones perform poorly in the very top-end of the audible frequency spectrum. It's not entirely uncommon for a dynamic microphone to have a high-end roll-off under 15 kHz (though the human hearing range typically goes to 20 kHz).
This isn't all bad, though, since this lack of high-end can yield results that are much less harsh than some condensers. That being said, it's often the case that a dynamic mic will lack that high-end brilliance or “shine” due to its lack of sensitivity in upper-frequency ranges.
More than the lack of high-end, dynamic mics are also often coloured. This means that some frequencies are more represented than others in the response of dynamic microphones.
This colouration is due to factors like the diaphragm weight and the acoustic labyrinth of the capsule/cartridge. In other words, the resonant frequencies of the capsule and the cavities within that capsule play a role in colouring the mic's frequency response. It's also true that some weaker frequencies (particularly in the high-end) will have a relatively difficult time moving the heavy moving-coil diaphragm.
To read an in-depth article on microphone frequency response, check out my article The Complete Guide To Microphone Frequency Response (With Mic Examples).
Though the transient response is a specification that is rarely discussed, it is important in describing the sound of a microphone. Condenser mics generally have fast transient responses, while dynamics are known to have slow transient responses.
Condenser microphones have very fast and accurate transient responses.
Condenser microphone diaphragms are generally very thin, lightweight, and reactive to sound waves at their surfaces. Therefore, their transient responses are very accurate.
Large-diaphragm condenser diaphragms are typically a bit slower due to their size and weight, while small diaphragms are faster.
Unfortunately, some condenser diaphragms “overshoot” their transient information. This happens when a mic is too reactive and artificially accentuates its transients. As with any microphone characteristic, this can be both a pro and/or a con depending on the application.
Dynamic microphones have slow transient responses.
Dynamic microphones have relatively heavy diaphragms that react more slowly to transient information due to inertia.
It's not entirely the diaphragm that is heavier, though the dynamic diaphragms are often heavier and thicker than condenser and ribbon diaphragms in order to hold the conductive coil. Rather, it's the attached coil that really adds weight to the dynamic mic diaphragm.
The slowness of the moving-coil dynamic diaphragm yields an almost compressed sound. Not only is the mic slower to react, but its diaphragm also takes longer to stop oscillating.
When it comes to polar patterns, condenser microphone design makes it easy to achieve any polar pattern and even makes it possible to design mics with multiple polar pattern options. Dynamic mics, conversely, will generally only have one polar pattern and cannot be bidirectional by the nature of their design.
Condenser mics can have any polar pattern.
Condenser microphone capsule designs single-diaphragm and dual-diaphragm models. Manufacturers use different amplitudes and polarities as well as acoustic labyrinths to create all sorts of polar patterns and even options for multiple polar patterns in a single microphone. Shotgun/lobar patterns are achievable by including a long interference tube in front of the capsule.
Dynamic mics can have any polar pattern except bidirectional.
Depending on the acoustic makeup of the capsule/cartridge, a moving-coil dynamic mic can have an omnidirectional or a unidirectional polar pattern.
The limiting factor that prevents dynamic microphones from achieving the bidirectional (figure-8) polar pattern is the coil on the reverse side of the diaphragm. Since the diaphragm's backside holds a coil and must be seated within a magnetic structure, it makes it impossible to have both sides of the diaphragm be equally open to sound waves.
Note that although an interference tube could be designed in front of a moving-coil dynamic mic, dynamics are not typically built as shotgun mics. Shotgun mics are always condensers.
To read more about microphone polar patterns, check out my article The Complete Guide To Microphone Polar Patterns.
Sensitivity ratings refer to the signal level a mic will produce when subjected to a certain sound pressure level. In general, active microphones (like condensers) are very sensitive, while passive microphones (like dynamics) have low sensitivity.
Condenser microphones are very sensitive.
Condenser microphones are active, meaning they have powered internal components that either truly amplifies the mic signal or boost its levels in other ways.
So condenser microphones will typically have higher sensitivity ratings. Their output levels will be relatively high when exposed to a certain sound pressure level.
Dynamic microphones are not very sensitive.
Dynamic microphones are passive, and their transducer principle (electromagnetic induction) doesn't create, by itself, a great amount of voltage as the diaphragm moves in reaction to sound waves.
Even with the boost of an output step-up transformer (which not all dynamic mics possess), the output is relatively low when exposed to a certain sound pressure level.
In other words, dynamic microphone signals will need more gain than condenser microphone signals in order to get boosted to line level.
For a deeper look into microphone sensitivity, check out my article What Is Microphone Sensitivity? An In-Depth Description.
It is only active components that add self-noise to microphones. This self-noise is apparent in the mic signal itself and negatively affects an active microphone's signal-to-noise ratio.
Condenser microphones have self-noise.
Active condenser microphone components (impedance converters, printed circuit boards, vacuum tubes) add self-noise to the mic signal. Any time the mic signal is amplified, there is potential for the noise-floor of the signal to also be raised and for self-noise to be apparent.
On top of that, but to a much lesser extent, the active components also produce a bit of noise. Quiet as it may be, this noise is picked up by the microphone.
Dynamic microphones do not have self-noise ratings.
Although all microphones will have some sort of noise-floor, dynamic microphones do not have a self-noise rating. This is because there are no active components that introduce noise to the microphone signals.
Instead, we must watch out for electromagnetic interference in dynamic microphones. We must also choose cleaner preamplifiers to boost dynamic mics' relatively low output signals to avoid excessive signal noise.
So although dynamic mics do not have inherent self-noise, we must be aware of general noise in their signals nonetheless.
To read more about microphone self-noise, check out my articles What Is Microphone Self-Noise? (Equivalent Noise Level).
Maximum Sound Pressure Level
Maximum sound pressure level refers to the SPL that would cause a microphone's signal to begin distorting.
Condenser microphones all have a max SPL.
All condenser microphones will have a max SPL rating. This is because it's easy to calculate the point at which their internal circuits will get overloaded. Often, this max SPL rating is in a practical range for actual sound sources a mic may be required to capture.
Note that it's extremely rare for the actual diaphragm and capsule of a condenser microphone to get overloaded. Max SPL, then, refers strictly to the point at which the signal will begin distorting within the internal circuits of the mic.
Dynamic microphones rarely have a max SPL.
The diaphragms and passive circuitry of dynamic microphones are practically immune to being overloaded.
Though there are often theoretical max SPLs for dynamic mics, these sound pressure levels are impractical in any normal application and are most often omitted from dynamic microphone specifications sheets.
For a deeper look into what is included on microphone specifications sheets, please consider reading my article Full List Of Microphone Specifications (How To Read A Spec Sheet).
For more reading material on max SPL, check out my article What Does A Microphone’s Maximum Sound Pressure Level Actually Mean?
Durability is an important factor when taking microphones on the road or when using any mic in less-than-ideal situations (extreme weather, temperature, and humidity, as well as in physically demanding or rough applications).
Though condensers are often built to last, the dynamic microphone family is home to the most durable microphones on the planet.
Most condensers are durable.
Although I would never recommend foul play with any microphone, most condensers are designed with longevity in mind.
This is particularly true of the solid-state (FET) condenser microphones. The printed circuit boards are stationary and durable; the condenser capsule is most often designed to be resistant to damage, and the entire mic is covered with a protective mic body and grille. In my experience, solid-state condensers will last a long time so long as they aren't subjected to high humidity or physical damage.
Multi-pattern condensers and mics with other switches are likely at a higher risk of damage due to having more moving parts.
Tube condensers are less durable. Vacuum tubes are made of glass and are fairly fragile. They are sensitive to temperature and can break if exposed to prolonged cold. Additionally, vacuum tubes will eventually wear out while solid-state electronics will last much longer.
Dynamic microphones are durable.
Dynamic microphones naturally have the toughest capsule/cartridge design. On top of that, their simple passive circuitry is extremely resilient and will not become damaged by reasonable temperature or humidity levels.
Shure, a famous microphone manufacturer that makes the world's greatest dynamic microphones (in my humble opinion), has several videos of their legendary SM57 and SM58 dynamic mics being put to the test.
In these videos, they set the mics on fire; freeze them; drive over them in a tour bus, and drop them from a helicopter. The results were a few dents and scratches, but the microphones remained fully functional, proving the durability of [at least the two most famous] dynamic microphones on the market.
Price and budget are always factors to take into consideration when buying and using microphones. Condenser microphones have a wide price range, while dynamic mics have a smaller range.
The price range of condenser microphones:
Condenser microphone prices range from less than $0.01 (for bulk orders of cheap electret mics) to well over $10,000 (for vintage tube condenser microphones). There are condenser microphones at every price point in between these two loosely defined limits.
The price range of moving-coil dynamic microphones:
Dynamic microphone prices range from under $10 for consumer-grade microphones to just shy of $1,000 for high-end dynamic mics.
For better resources on microphone pricing, check out the following My New Microphone articles:
• How Much Do Microphones Cost? (With Pricing Examples)
• Top 20 Most Expensive Microphones On The Market Today
What are the differences between condenser and ribbon microphones? The main difference between ribbon and condenser mics is that ribbon mics convert sound via electromagnetic induction, and condensers do so via electrostatic principles. Ribbon mics have conductive ribbon-like diaphragms and simple circuitry, while condensers have active capsules and complex circuitry.
To learn more about condenser mics, ribbon mics, and their differences, check out my article The Differences Between Condenser And Ribbon Microphones.
What are the differences between moving-coil and ribbon dynamic microphones? In moving-coil dynamic mics, the mic signal is induced across a conductive element (coil) attached to a diaphragm. With ribbon mics, the diaphragm itself acts as the conductor. Moving-coil mics benefit from better durability, ease of use, and lower prices, while ribbon mics sound much more natural.
To read more about the differences between moving-coil dynamic and ribbon dynamic mics, check out my article Differences Between Moving-Coil & Ribbon Dynamic Microphones.
For more information on ribbon mics, check out my article Dynamic Ribbon Microphones: The In-Depth Guide.
Choosing the right microphone(s) for your applications and budget can be a challenging task. For this reason, I've created My New Microphone's Comprehensive Microphone Buyer's Guide. Check it out for help in determining your next microphone purchase.