The subcardioid or “wide cardioid” microphone polar pattern is a lesser-known cousin to the famous cardioid pattern. Knowing about this polar pattern and its pros and cons will certainly aid in mic selection and understanding, whether you're an amateur or professional.
What is a subcardioid/wide cardioid microphone? A subcardioid (aka wide cardioid) microphone has a polar pattern that resembles the midway point between an omnidirectional and cardioid pattern. It is unidirectional (most sensitive to on-axis sounds) but will also pick up sound with clarity from every direction (though with less amplitude).
In this in-depth article, we'll discuss the subcardioid/wide cardioid microphone polar pattern in great detail to answer any questions you may have about subcardioid microphones!
The Subcardioid Polar Pattern
A picture is worth a thousand words. Let's start with a diagram of the cardioid microphone polar pattern:
I like to imagine the wide cardioid as a cross between an omnidirectional pattern and a cardioid pattern.
The subcardioid polar pattern is unidirectional since it is most sensitive in only one direction. However, unlike the other major unidirectional pattern, the subcardioid does not have any null points.
Instead of null points and lobes of sensitivity, the wide cardioid pattern is simply less sensitive to sounds from the back compared to the front. This allows wide cardioid mics to sound relatively natural, like omnidirectional mics, while retaining some of the upsides of being unidirectional.
Subcardioid Microphone Generalities And Characteristics
- No null points
- No lobes of sensitivity
- Roughly 3 dB less sensitive at the sides (90° & 270°)
- Roughly 10 dB less sensitive at the rear (180°)
- Exhibits relatively little proximity effect
- Fairly resistant to vocal plosives
- Relatively natural-sounding polar pattern
- Prone to feedback (low gain-before-feedback)
- Not an overly popular primary microphone polar pattern
- A natural occurring pattern in the high-end of omnidirectional mics
- Great for close and distance-miking
- Becomes more directional at higher frequencies (becoming more cardioid or even supercardioid)
- Becomes less directional at lower frequencies (may take the shape of an omnidirectional pattern)
- Works on the pressure-gradient principle
- A 7:3 ratio of an omnidirectional and bidirectional pattern (superposition)
No Null Points
Unlike the other common directional polar patterns, the wide cardioid has no null points.
However, just because there is no angle of sound rejection, the subcardioid pattern still has a point where it is least sensitive. This point happens to be to the rear (180°), where the typical subcardioid mic is roughly 10 dB less sensitive than 0° on-axis.
No Lobes Of Sensitivity
The subcardioid mic resembles the midway point between a cardioid and omnidirectional pattern and exhibits no lobes of sensitivity.
The subcardioid polar pattern is unidirectional even though it doesn't have the null points or lobes typically associated with unidirectional mics.
Unidirectionality means the subcardioid is most sensitive in only one direction, which is on-axis at 0°.
Roughly 3 dB Less Sensitive At The Sides (90° & 270°)
Although the subcardioid pattern is unidirectional, it is not overly directional. It is indeed the most sensitive on-axis. However, its sensitivity only drops about 3 dB at its sides, which means it isn't overly directional.
If we were to base our angle of acceptance on a 3 dB drop, the typical subcardioid would have a very wide acceptance angle of 180°!
Roughly 10 dB Less Sensitive At The Rear (180°)
The typical subcardioid pattern is roughly 10 dB less sensitive in the back than in the front. This helps subcardioid mics to exhibit some of their inherent directionality.
Exhibits Relatively Little Proximity Effect
The subcardioid mic will exhibit proximity effect since it is a pressure-gradient-type microphone pattern. However, its relatively omnidirectional polar response helps minimize the proximity effect to some extent.
This is due to the limitations imposed on the sound waves travelling through the acoustic labyrinth on their way to the rear of the subcardioid diaphragm.
To learn more about how the proximity effect works, check out my article What Is Microphone Proximity Effect And What Causes It?
Fairly Resistant To Vocal Plosives
Again, because the subcardioid polar pattern is based on the pressure-gradient principle, it will be sensitive to vocal plosives. However, due to the nature of the wide-open polar pattern, it will likely resist vocal plosive overloads better than the other directional polar patterns.
This is, again, due to the limitations imposed on the sound waves travelling through the acoustic labyrinth on their way to the rear of the subcardioid diaphragm.
For a more in-depth discussion on vocal plosives and how to eliminate them in your microphone recordings, check out my article Top 10 Tips For Eliminating Microphone Pops And Plosives.
Relatively Natural-Sounding Polar Pattern
Like the closely related omnidirectional polar pattern, the subcardioid sounds very natural. This is partly because of the following points:
- No null points or lobes of sensitivity.
- Typically a fairly consistent pattern.
- Little off-axis colouration or attenuation
- Little proximity effect
Prone To Feedback (Low Gain-Before-Feedback)
Because of the slight omnidirectional nature of the subcardioid and its lack of null points, the polar pattern is quite prone to feedback in live sound situations.
Even though the ideal subcardioid is unidirectional, it is still sensitive, in some capacity, to sounds from all directions. This is a recipe for feedback in live sound reinforcement situations.
To read more about microphone feedback, check out my article 12 Methods To Prevent & Elminate Microphone/Audio Feedback.
Not An Overly Popular Primary Microphone Polar Pattern
There aren't a whole lot of subcardioid or wide cardioid microphones on the market. I'd say they are probably the least popular polar pattern.
However, many microphones exhibit subcardioid-like pickup response patterns at low frequencies, which we'll get to soon.
A Natural Occurring Pattern In The High-End Of Omnidirectional Mics
As omnidirectional microphones get more directional at higher frequencies, they often exhibit a pattern close to the subcardioid.
Great For Close And Distance-Miking
The natural-sounding pickup of subcardioid mics makes them a great choice for close and distant mic placement.
Close-miking with a subcardioid mic is great for a natural, slightly directional sound with little to no proximity effect or risk of plosive overloads. The subcardioid mic will also pick up much of the acoustic environment along with the intended sound source.
Distance-miking with a subcardioid is great when we want to increase the directionality of an omnidirectional microphone-based technique. For example, swapping out the omnis in a spaced pair with subcardioids will help to reduce the room sound while maintaining a similar character of the main sound source(s).
Becomes More Directional At Higher Frequencies
As with all microphones, subcardioid mics naturally become more directional at higher frequencies. Oftentimes a subcardioid mic will exhibit a more hypercardioid-like pattern at the upper end of its frequency response.
Becomes Less Directional At Lower Frequencies
In reality, subcardioid mics will likely become more omnidirectional at lower frequencies.
Works On The Pressure-Gradient Principle
Subcardioid microphones work on the pressure-gradient principle. This basically means that the two sides of a subcardioid mic's diaphragm are open to external sound pressure.
An acoustic labyrinth is required to delay and dampen the sound waves around the rear of the diaphragm before they reach the diaphragm. This is what ultimately creates the omnidirectional-like pattern of the subcardioid!
Related article: Pressure Microphones Vs. Pressure-Gradient Microphones
A 7:3 Ratio Of An Omnidirectional And Bidirectional Pattern
A cardioid can be explained as a 1:1 superposition of an omnidirectional pattern and a bidirectional pattern.
It's much more difficult to visualize abstractly, but a subcardioid polar pattern could then be described as a 7:3 ratio of an omnidirectional pattern and a bidirectional pattern.
How Is The Subcardioid Polar Pattern Achieved?
The subcardioid/wide cardioid is achieved with the pressure-gradient acoustic principle, which has both sides of the microphone diaphragm open to external sound pressure.
The front side of the microphone diaphragm is completely exposed to sound waves. The rear side, however, is encompassed by an acoustic labyrinth that limits the sound waves' ability to reach the diaphragm.
This results in the subcardioid microphone being more sensitive to sounds coming from the front and less so to the rear.
Note that there are no null points in this polar pattern. The subcardioid is similar to an omnidirectional mic in that way. In fact, many omnidirectional mics take on a more subcardioid pattern at higher frequencies (since microphones naturally become more directional at higher frequencies).
How Is The Subcardioid Polar Pattern Achieved In Multi-Pattern Microphones?
Some multi-pattern microphone capsules, like the famous AKG CK 12, offer subcardioid or wide cardioid options.
Multi-pattern mics typically utilize a dual-membrane capsule with back-to-back cardioid diaphragms/”capsules.” The various polar pattern options are obtained by combining the signals of the two diaphragms in varying phase and amplitude relationships.
To achieve the wide cardioid polar pattern, these capsules combine the two cardioid patterns in equal polarity but with greater amplitude of the front-facing mic signal than the rear-facing mic signal.
When Should You Use A Subcardioid Microphone?
Although subcardioid is an uncommon microphone polar pattern and likely won't be chosen for many applications, there are some instances where using a subcardioid mic would be greatly beneficial.
Best Applications For Subcardioid Microphones
- In any situation that would require a slightly more directional omnidirectional microphone.
- To capture a sound source and the sound of the acoustic environment.
- For single sources in isobooths where less proximity effect is wanted.
- For single sources in isobooths to reduce the risk of vocal plosives.
- For a natural pickup with some directionality.
- To capture sounds naturally in the front while have some rejection of sound to the rear.
That being said, there are also times where a subcardioid pattern would be sub-optimal:
When Shouldn't You Use A Subcardioid Microphone?
- In live sound reinforcement situations that call for high gain-before-feedback.
- To record single sound sources in less-than-ideal acoustic environments.
- To close-mic/isolate a single sound source in noisy environments.
List Of Miking Techniques With Subcardioid Microphones
Here is a list of miking techniques that include subcardioid microphones:
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Subcardioid Microphone Examples
- Microtech Gefell M 950
- Schoeps MK 21 / CMC 6
- Audio-Technica AT808G
- DPA d:dicate 4015A
- Sennheiser MKH 8090
Microtech Gefell M 950
Microtech Gefell's M 950 is the wide cardioid model of their M 900 line of microphones (the supercardioid M 940 is featured in my article on supercardioid microphones). It is a side-address large-diaphragm condenser microphone with a wide cardioid polar pattern. This microphone works amazingly well by itself and especially as a matched pair in spaced and near coincident stereo and surround sound miking techniques.
The Microtech Gefell M 950 Polar Response Graph
Microtech Gefell gives us 3 separate diagrams with 7 measurement frequencies in the response pattern graphs of their M 950. Each of the 3 diagrams shows the standard 1 kHz pattern for comparison.
The M 950 exhibits a wonderfully wide cardioid pattern for most of its frequency response. It is only at the 8 kHz mark that the microphone becomes more supercardioid-like. An octave above that, at 16 kHz, the mic becomes extremely directional.
This is important to note in order to understand the off-axis colouration of the M 950.
Schoeps MK 21 / CMC 6
The MK 21 is Schoeps' wide cardioid model in their Colette series of microphone capsules. The CMC 6 is their most popular amplifier for their modular mics. Schoeps' MK 21 is a top-address small diaphragm condenser capsule with an extremely consistent subcardioid polar pattern. Its natural-sounding pickup and wide frequency response allow it to excel as a main mic, room mic, or spot mic in live and studio settings.
The Schoeps MK 21 Polar Response Graph
Schoeps creates high-quality, consistent microphones. The polar response graph of the MK 21 proves the consistency of this particular subcardioid microphone capsule.
The MK 21 has no null points anywhere across its frequency response. It shows a smooth attenuation between 0 dB at 0° and roughly -10 dB at 180° throughout the audible frequency range.
At 16 kHz, the microphone becomes slightly more directional, contributing to the slightest amount of off-axis colouration. This is to be expected of any mic.
The Audio-Technica AT808G is a top-address gooseneck dynamic microphone. Its small moving-coil cartridge yields a subcardioid polar pattern. The AT808G excels as a podium mic. Its wide acceptance angle allows the speaker/presenter to move their heads without overly affecting the sound level or quality of the microphone. At the same time, there is enough rear and side rejection that the microphone effectively isolates the speaker/presenter while providing decent gain-before-feedback.
The Audio-Technica AT808G Polar Response Graph
The Audio-Technica AT808G has a fairly consistent subcardioid polar response, as shown in the graph above. Note the loosening of the pattern at lower frequencies and the tightening of the pattern at higher frequencies. At the 1 kHz standard, the AT808G looks near-ideal for a subcardioid mic!
DPA d:dicate 4015A
The DPA d:dicate 4015A features DPA's 4015 modular subcardioid microphone capsule with its high-quality pencil amplifier. It is a top-address pre-polarized small-diaphragm condenser microphone. Its wide cardioid polar response is incredibly consistent, which makes the 4015A sound beautifully natural on any sound source. Off-axis sounds are subjected to near-negligible colouration and are attenuated in level.
The DPA d:dicate 4015A Polar Response Graph
DPA provides us with a very colourful and accurate polar response graph for their 4015A. We see that it exhibits a consistent subcardioid polar pattern throughout the vast majority of the mic's frequency response.
The mic's rear 180° attenuation ranges from about 4 dB at 250 Hz to about 6 dB at 4 kHz. The gradual attenuation from the on-axis to the off-axis makes this microphone sound incredibly natural.
As we'd expect, at the upper end of the audible frequency spectrum (noted by 16 kHz), the 4015A becomes very directional, abandoning its otherwise consistent wide cardioid pattern.
Sennheiser MKH 8090
The Sennheiser MKH 8090 is a compact top-address small-diaphragm condenser microphone with a wide cardioid polar pattern. This microphone is perfect for spot-miking instruments and vocalists and as a replacement for omnidirectional room mics when less room sound is wanted in the mix.
The Sennheiser MKH 8090 Polar Response Graph
The Sennheiser MKH 8090 is yet another incredibly consistent wide cardioid microphone.
There is minimal variation in the polar response of the 8090 between 125 Hz and 8,000 Hz. The smooth attenuation from 0 dB on-axis to roughly -6 dB at 180° allows this microphone its natural-sounding pickup.
At 16 kHz, the pattern becomes quite a bit tighter and more rejecting of side sounds. Sennheiser includes measurement at 32 kHz, which is rare in mic polar pattern graphs since this frequency is outside the human hearing spectrum. At 32 kHz, we see a very irregular polar pattern that is difficult to put a name to.
All The Different Microphone Polar Patterns
Here's a list of all the different polar patterns you'll likely encounter when using microphones:
By clicking the links of each polar pattern title, you'll be brought to a My New Microphone article that focuses on that specific polar pattern.
- Omnidirectional: picks up sound equally in all directions.
- Bidirectional: picks up sound symmetrically in the front (0°) and back (180°) with equal sensitivity but opposite polarity. Bidirectional patterns have null points at their sides (90° & 270°), which yields a “ring of silence” in 3D space. Their polar pattern looks like a figure-8 in 2D.
- Cardioid: unidirectional pattern with a null point at the rear (180°) and roughly 6 dB decrease in sensitivity at its sides (90° & 270°) compared to on-axis (0°).
- Supercardioid: unidirectional pattern with a narrower on-axis response than “regular” cardioid. Null points at 127° & 233°, which yields a “cone of silence.” There's roughly a 10 dB decrease in sensitivity at its sides (90° & 270°) and a rear lobe of sensitivity with 10 dB less sensitivity (at 180°) compared to on-axis (0°).
- Hypercardioid: unidirectional pattern similar to supercardioid with a narrower on-axis response than “regular” cardioid. Null points at 110° & 250°, which yields a “cone of silence.” There's roughly a 12 dB decrease in sensitivity at its sides (90° & 270°) and a rear lobe of sensitivity with 6 dB less sensitivity (at 180°) compared to on-axis (0°).
- Subcardioid/Wide Cardioid: A unidirectional pattern with a wider response than “regular” cardioid. Subcardioid can be thought of as a midway point between cardioid and omnidirectional.
- Shotgun/Lobar: An extension on the supercardioid and hypercardioid polar patterns. The use of an interference tube in front of an already highly directional capsule yields the extremely directional shotgun/lobar pattern. These patterns generally have a rear lobe of sensitivity and sometimes even have small side lobes of sensitivity.
- Boundary/PZM (Hemispherical): The hemispherical polar pattern found on boundary and pressure zone microphones. These patterns are achieved by placing the mic capsule flush to a flat surface and then placing the microphone itself at a surface/boundary within an acoustic space. The capsules themselves can be any polar pattern, though omnidirectional capsules are often preferred.
For an in-depth definition of all the polar response patterns listed above (and much more), check out my article The Complete Guide To Microphone Polar Patterns.
What is the function of a microphone? A microphone is a transducer of energy. Its function is to convert mechanical wave energy (sound waves) into coinciding electrical energy (audio signals). In other words, mics turn sound into audio. There are various methods to achieve this conversion, but all have some sort of vibrating diaphragm.
What are the two main types of microphones? The two main types of microphones, when referring to the type of transducer, are condenser and dynamic. Condensers convert sound to audio via electrostatic principles, while dynamics convert sound to audio via electromagnetic principles.
For more information on the condenser microphone type, dynamic microphone type, and sub-types, check out my article Microphone Types: The 2 Primary Transducer Types + 5 Subtypes.
To learn more about all the microphone polar response patterns, check out my article The Complete Guide To Microphone Polar Patterns.
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.