Condenser Microphones – Page 3

Ribbon and condenser microphones are two types of microphones that are both popular in the studio. Although these microphones are cherished by musicians, engineers, and audiophiles alike, they are different from one another in many ways. What are the differences between ribbon and condenser 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. This quick answer tells us the big picture difference. However, we should be aware of many other differences and generalities between ribbon and condenser microphones. In this article, we'll discuss these differences in detail. Ribbon Vs. Condenser Microphones Tables are an easy way to disseminate information. Let's look at the differences between ribbon and condenser mics in the following table: Ribbon MicrophonesCondenser Microphones Transducer PrincipleElectromagnetic inductionElectrostatic principles Active/PassivePassive or activeActive Frequency ResponseNaturalFlat/extended Transient ResponseAccurateFast Polar PatternsNaturally bidirectionalAll (especially with dual-diaphragm capsule) SensitivityVery low (high if active)High Self-NoiseNo (yes if active)Yes Maximum Sound Pressure LevelOften too high to measureOften within practical limits Transformer coupled outputPassive: always Active: sometimesSometimes DurabilityFragileSomewhat durable PriceModerateCheap to very expensive To read more about ribbon microphones, check out my article Dynamic Ribbon Microphones: The In-Depth Guide. Similarities Between Ribbon And Condenser Microphones As I mentioned above, these two microphone types are commonplace in studios, though condensers are certainly more popular. Other than the fact both types are microphones, that's pretty much where the similarities stop. Though most ribbon microphones are passive, some models are active and contain active circuitries (field-effect transistors, amplifiers, and printed circuit boards) somewhat similar to those found in most condenser microphones. Transducer Principle The greatest difference between ribbon and condenser microphones is the difference in transducer principles. Ribbon mics work on electromagnetic induction while condenser mics convert sound to audio via electrostatic principles. Ribbon 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 simple diagram of a ribbon microphone baffle (transducer element): The ribbon-like diaphragm of a ribbon mic is made of conductive material (most often aluminum). This ribbon is suspended within a magnetic baffle and moves according to the varying sound pressure at its surface. So as the conductive ribbon diaphragm moves within the permanent magnetic field supplied by the baffle, it experiences a change in the field. This causes a voltage to be induced across the ribbon. As the ribbon moves back and forth about its resting position, a coinciding AC voltage (microphone signal) is created. Condenser microphones work on electrostatic principles. To explain this, we must understand that a condenser microphone capsule acts as a parallel-plate capacitor. Here is a diagram of a condenser microphone capsule (transducer element): This capacitor is made up of a movable front plate (the diaphragm) and a stationary backplate. It is permanently charged with a fixed amount of charge, which is 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 proportionate change in voltage. The distance between the two plates is a factor in the capacitance of the condenser capsule. So, as the diaphragm moves according to sound pressure, it alters the distance between the plates and, therefore, the capacitance of the capsule. This alternating capacitance causes an inversely proportionate AC voltage (mic signal) to be created across the capacitor. To learn more about microphone capsules, check out my article What Is A Microphone Capsule? (Plus Top 3 Most Popular Capsules). Active/Passive All condenser microphones are active, meaning that they require power to function properly. Most ribbon microphones (but not all), on the other hand, are passive and do not require power to function. Condenser microphones are always active. All condenser microphones require power to function properly. The active components that require powering 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). Ribbon microphones are typically passive. As mentioned, ribbon mics work on electromagnetic induction, which requires no power to take place. Ribbon mics typically have output transformers which are also passive. A relatively simple circuit of the ribbon baffle and the output-coupled transformer makes up many ribbon microphones. Royer R-121 passive ribbon microphone The Royer R-121 is featured in the following My New Microphone articles:• 50 Best Microphones Of All Time (With Alternate Versions & Clones)• Top 12 Best Passive Ribbon Microphones On The Market However, some ribbon mics are designed with active components to help boost their relatively weak mic signals. These components include vacuum tubes, printed circuit boards, amplifiers, and even impedance converters. Royer R-122 active ribbon microphone The Royer R-122 is featured in My New Microphone's Top 11 Best Active Ribbon Microphones On The Market. Royer Labs is featured in My New Microphone's Top 11 Best Microphone Brands You Should Know And Use. For more information on active and passive microphones, check out my article Do Microphones Need Power To Function Properly? Frequency Response Generally speaking, ribbon microphones have natural-sounding frequency responses, while condenser microphones have very accurate but sterile-sounding frequency responses. Condenser microphones have relatively flat and extended frequency responses, often with slight increases in sensitivity in the upper-frequency range. Many condenser microphones will have a fairly flat frequency response across the audible spectrum (20 Hz - 20,000 Hz). This means they'll capture audio very accurately. Large-diaphragm condensers often have a slight boost in the high-frequency range followed by a slight roll-off at the very high-end. This helps to add presence to the mic signal but may also cause the mic to sound harsh. Neumann TLM 102 (large-diaphragm condenser) frequency response Small-diaphragm condensers benefit from extended frequency responses (sometimes well above the audible spectrum) and a flatter high-end frequency response. Neumann KM 184 (small-diaphragm condenser) frequency response Condenser mic diaphragms are often tuned in such a way that their natural resonant frequencies are diminished in their frequency response. Ribbon microphones have relatively flat frequency responses with gradual, natural-sounding high-end roll-offs. Most ribbon mics have a fairly flat frequency response until their descriptive gentle roll-off of high frequencies. This roll-off is often described as sounding "natural" since our ears naturally lose sensitivity in these upper-frequency ranges. Ribbon microphones are suspended relatively loose in their baffles, and so typically, their resonant frequency is well below the range of human hearing. AEA R84 ribbon microphone frequency response If we look at the history of microphone popularity, we'll see that ribbon microphones fell out of favour in the era of analog tape recording, and condensers took over. This is because the "natural" high-end roll-off of the ribbon microphones would compound with the high-end roll-off of tape. As a result, the ribbon mics sounded very muffled and dull. On the other hand, Condenser microphones were very bright and helped to offset the analog equipment and tape's naturally diminished high-end. Fast forward to the days of digital recording, and we see a resurgence of ribbon microphones. The roll-off of the ribbon mic now sounds fuller and more natural in the sterile recording of digital audio. On the contrary, condenser microphones are criticized for sounding overly bright and even harsh on digital recordings due to their seemingly great high-end frequency response. For more information on microphone frequency response, check out my article Complete Guide To Microphone Frequency Response (With Mic Examples). Transient Response In general, the transient responses of ribbon and condenser microphones are accurate. However, the edge on transient response would have to go to ribbon microphones. Condenser microphones have very fast and accurate transient responses. The diaphragms of condenser microphones are generally very thin and very reactive to the sound pressure variations at their surfaces. This means their transient responses are very accurate. Large-diaphragm condenser diaphragms are typically slightly slower due to their size and weight, while small diaphragms are faster. Unfortunately, some condenser diaphragms are a bit too reactive and portray "overshoot," where they artificially accentuate transients. As with any microphone characteristic, this can be both a pro and/or a con depending on the application. Ribbon microphones have very natural transient responses. The extremely thin yet relatively loosely suspended diaphragm or a ribbon mic typically reacts to transients very naturally. The typical ribbon mic has a transient response that very closely represents the real transients in the sound around it. Rarely is there overshoot, and rarely does the ribbon act slower than the actual sound transient at its diaphragm. Polar Patterns While condenser microphones can easily achieve any polar pattern (and are often multi-pattern), ribbon mics are naturally bidirectional. Condenser mics can have any polar pattern. Condenser mic capsules are easily designed to portray any polar pattern the manufacturer desires. These capsules can be designed with one diaphragm and an acoustic labyrinth to create omnidirectional or unidirectional patterns. Shotgun/lobar patterns are achievable by including a long interference tube in front of the capsule. Condenser capsules can also be designed with dual-diaphragms to achieve the bidirectional pattern and allow multiple switchable polar patterns within the same microphone. Ribbon mics have a bidirectional polar pattern by default. Most ribbon mics on the market today will have a bidirectional polar pattern due to the nature of their design. Bidirectional (figure-8) polar pattern 2-D diagram/graph A ribbon mic baffle works with a suspended, conductive ribbon with its front and back open to sound and its sides closely surrounded by a magnetic structure. Therefore, the ribbon is naturally equally sensitive to sounds from the front and back. Other polar patterns are achievable by altering the acoustic labyrinth around the diaphragm, which offsets or even stops sound from reaching one side of the ribbon diaphragm. To read more on microphone polar patterns, please consider reading my articles The Complete Guide To Microphone Polar Patterns and What Is A Bidirectional/Figure-8 Microphone? (With Mic Examples). Sensitivity Between ribbon, dynamic, and condenser microphones, ribbon mics are generally the least sensitive, while condensers are generally the most sensitive. To read my article on the general differences between all three mic types, check out Differences Between Dynamic, Condenser, & Ribbon Microphones. Condenser mics are very sensitive. As we've discussed, Condenser microphones have internal components that either truly amplify the mic signal or at least boost its levels in other ways. This means that the typical condenser microphone will have a higher sensitivity rating than its passive counterparts. Ribbon microphones are not very sensitive. The majority of ribbon microphones are passive. They rely on a strong magnetic field to induce a decent mic level signal in the diaphragm and a high-quality output transformer to help boost the voltage of the signal. These passive electromagnetic devices do not produce a very strong mic signal and, therefore, ribbon mics do not have very high sensitivity ratings. That being said, some ribbon microphones are active and have similar active components to condenser mics. Active ribbon microphones can have very high sensitivity ratings. This is often a huge benefit since we do not need to rely so heavily on preamp gain to boost high-sensitivity mic signals to line level! For a deeper look into microphone sensitivity, check out my article What Is Microphone Sensitivity? An In-Depth Description. Self-Noise Self-noise ratings belong to active microphones, so condensers and active ribbons all have self-noise while passive ribbons do not. Condenser microphones have self-noise. The active components (impedance converters, printed circuit boards, vacuum tubes) all produce a bit of noise. Quiet as it may be, this noise is picked up by the microphone. But the most relevant issue in terms of self-noise is the noise these active components add to the signal. Any time the mic signal is amplified, there is potential for the noise-floor of the signal to also be raised. Active ribbon mics have self-noise, but passive ribbon mics do not. For the reasons stated above, active ribbon microphones also have self-noise. On the other hand, passive ribbon microphones do not have self-noise ratings because there are no devices in the mics that add noise to the signal. To learn more about microphone self-noise, please read through my article What Is Microphone Self-Noise? (Equivalent Noise Level). Maximum Sound Pressure Level A microphone's maximum sound pressure level refers to the SPL at the mic diaphragm that will cause the microphone to produce a distorted audio signal. Condenser microphones all have a max SPL. All condenser microphones will have a max SPL rating since 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. Ribbon microphones also typically have a max SPL. On the other hand, Ribbon microphones have a max SPL rating that refers to the point when the ribbon diaphragm itself will start behaving non-linearly. It's much easier to "overload" the thin ribbon diaphragm than it is to overload the passive electronics of a ribbon mic. This max SPL rating is often (but not always) above the practical sound pressure levels a ribbon mic would be exposed to. Depending on an active ribbon microphone's inner circuitry and components, we could have a max SPL in the range of possibility. To read into max SPL in greater detail, click through to my article What Does A Microphone’s Maximum Sound Pressure Level Actually Mean? Transformer Or Transformerless? An output transformer helps balance the audio and adjust the mic signal voltage before the microphone's signal is finally outputted. Some condenser microphones have transformers. It used to be that when condenser microphones needed vacuum tube electronics, all condenser mics had output transformers. This was to help balance the audio and provide some final adjustments to the signal before the output. Most often, these were step-down transformers that were used to fix the impedance of the mic signal rather than the voltage (strength). Neumann KM 84 (1966) condenser microphone has an output transformer The Neumann KM 84 is featured in the following My New Microphone articles:• 50 Best Microphones Of All Time (With Alternate Versions & Clones)• Top 12 Best Vintage Microphones (And Their Best Clones) Early solid-state condensers also had transformers. However, in the late 1970s, manufacturers began opting for transformerless output designs. Neumann KM 184 (1993) condenser microphone has a transformerless output The Neumann KM 184 is featured in the following My New Microphone articles:• 50 Best Microphones Of All Time (With Alternate Versions & Clones)• Top 12 Best Vintage Microphones (And Their Best Clones)• Top 11 Best Solid-State/FET Condenser Microphones Neumann is featured in the following My New Microphone articles:• Top 11 Best Microphone Brands You Should Know And Use• Top 11 Best Studio Monitor Brands You Should Know And Use These designs were made of solid-state electronics that could potentially reduce noise and certainly reduce cost and real estate within the microphone. High-quality transformers have not dropped much in price over the ages, but transistors and other solid-state components continue to become cheaper. Today, there are many condensers on the market with and without transformers. Nearly all ribbon microphones have transformers. All passive ribbon microphones have step-up transformers to boost the ribbon diaphragm's low-level signal and help protect the microphone from unwanted DC voltage (like phantom power). However, like the solid-state condensers above, some active ribbon microphones are designed with balanced, transformerless output circuitry rather than transformers. I should note that active tube ribbon mics typically do have output transformers, like their tube condenser counterparts. To read more about transformers (and transistors, for that matter), please check out my article Do All Microphones Have Transformers And Transistors? (+ Mic Examples). Durability At the beginning of this article, I mentioned the popularity of both ribbon and condenser microphones in the studio. Although studio microphones do not need to be the most durable, it's still an important aspect of microphone longevity. Condenser mics are typically pretty durable, while ribbons ofter require a bit more caution and care when in use and when not in use. Most condensers are durable. Although I would never recommend foul play with any microphone, most condensers are built to last. This is particularly true of the solid-state (FET) condenser microphones. The printed circuit boards are stationary and durable; the condenser capsule is typically fairly resistant to damage, and the entire mic is covered with the mic body and grille. Some multi-pattern condensers may be at higher risk of damage since they have more moving parts. However, in my experience, solid-state condensers will last a long time so long as they aren't subjected to high humidity or physical damage. Tube condensers, on the other hand, are less durable. Vacuum tubes are made of glass and are relatively 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. Ribbons are fairly fragile. Ribbon diaphragms are notoriously fragile. The benefit of passive ribbon mics is that they are fairly resistant to temperature and humidity. However, the downside is that their diaphragms can be easily stretched or snapped. Sharp particles in the air have been known to tear a ribbon diaphragm or two, so care should be taken when moving a ribbon mic around. Shorting the connection to a ribbon mic when any DC bias or phantom power is on the line can also damage the ribbon. It's best to avoid hot patching a ribbon mic altogether. Price Ribbon and condenser microphones both have wide price ranges, though the condenser microphones easily out-range the ribbons. 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 ribbon microphones: Ribbon microphone prices range from under $100 for consumer-grade ribbon microphones to multiple thousand dollars for the high-end (mostly active) ribbon mics and vintage models. For more information on the price of microphones, check out the following My New Microphone articles: How Much Do Microphones Cost? (With Pricing Examples) and Top 20 Most Expensive Microphones On The Market Today. Related Questions What are the differences between condenser and moving-coil dynamic 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. To learn about the differences between condenser and moving-coil dynamic mics in greater detail, check out my article Differences Between Dynamic & Condenser Microphones. What are the differences between ribbon and moving-coil 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. For more information on the differences between moving-coil and ribbon dynamic mics, check out my article Differences Between Moving-Coil & Ribbon Dynamic Microphones. For an in-depth read on dynamic microphones, check out my article Moving-Coil Dynamic Microphones: The In-Depth Guide.