What is Proximity Effect?
The microphone proximity effect is usually used to get a nice effect, and on different occasions, it is an unwanted side effect of mic placement. It may possibly accentuate the deep voice of a speaker, the low thud of a kick drum, and the boominess of a bass amplifier.
It will possibly also cause muddiness and an overrepresentation of low-end frequencies in a mic signal that does not necessarily want it.
What does this mean, and how can we exploit the microphone proximity effect to our benefit as performers and audio technicians? These questions will likely be answered in this article!
What is Proximity Effect?
The proximity effect is a little bit of technical jargon you’ll usually hear utilized in reference to people speaking into microphones. You may listen to its audible effect on podcasts, YouTube, and different streaming platforms.
It’s easy to demonstrate, however understanding exactly why it happens requires at least a cursory knowledge of some basic physics. For a definition, the proximity effect is an increase in the proportion of low-frequency output that happens as the distance between a directional microphone and the sound source is reduced to the point where they’re very close or almost touching.
In other words: the nearer the microphone gets to the sound source, the greater the bass boost! The proximity effect is a phenomenon that leads to an increase in low-frequency response as you move the mic nearer to the source. The closer you get, the larger the bass boost.
This may create issues, but simultaneously it opens up methods to shape the sound. The proximity effect results from phase and amplitude variations of the sound waves arriving on the two sides of the microphone’s diaphragm. These variations are explained by the other ways sound radiates through the air, depending on the frequency and distance from the source.
The Pros and Cons of the Proximity Effect
The proximity effect may also compromise speech intelligibility and make the low-end sound muddy when “fattened” vocals and guitars get in the way of bass and kick drum. So the proximity effect is a good friend and an enemy at the same time.
It would help if you utilized it to make things big, fat, and attractive, however, you need to keep it in check for excellent overall stability and maximum transparency. Obviously, the proximity effect is most noticeable in sounds with plenty of low-frequency content below 200 Hz. So it’s a necessary factor while you record male voices, especially in the lower range, but it surely’s of much less consequence for female voices.
The proximity effect is usually an issue while you record guitars (the E-string is around 80 Hz). Acoustic guitars, particularly, often sound very “boomy” when you place your mic too close. However, for dedicated bass instruments similar to kick drums, bass guitars, or upright bass, the proximity effect may be helpful to create big fat low frequencies.
Proximity Effect On Different Mic Patterns
The strength of the proximity effect is determined by the microphone’s pickup pattern. It’s strongest on figure-8 microphones, and still pretty strong (though somewhat less) on cardioid.
Omnidirectional microphones don’t have any proximity effect in any respect. Well, there are two varieties of transducers: pressure transducers and pressure gradient transducers. The proximity effect happens solely on pressure gradient transducers (which reply to the difference in sound pressure between the back and front of the diaphragm).
Cardioid microphones, which make up the majority of models, are a 50:50 combination of pressure and pressure gradient transducers. The proximity effect occurs in numerous levels of intensity with several types of microphones (e.g., pressure gradient microphones) and polar patterns.
It doesn’t occur in any respect with the Omnidirectional pattern, and it’s most pronounced with the figure-8 pattern. Probably the most commonly used pattern is the cardioid polar pattern, and it has a reasonably strong proximity effect.
Proximity Effect with Multi-Pattern Mics
It is a kind of microphone – mostly large-diaphragm condensers – that’s pretty common in the studio but hardly ever seen for stage applications. A famous example is the Neumann U87, probably the most widely used studio microphone around the globe.
Multi-pattern microphones achieve totally different pickup patterns by electrically combining the 2 parts of a dual-diaphragm capsule. As a result of each of these halves having a cardioid pattern, some people claim that a multi-pattern mic will always have a powerful proximity effect, whatever the pickup sample is chosen.
Nonetheless, Neumann’s research has confirmed this to be untrue. Concerning the proximity effect, multi-pattern microphones behave pretty much like fixed pattern, single diaphragm Omni, cardioid, or figure-8 microphones. So the strong proximity effect changes with the pickup pattern chosen.
Or, to place it in practical terms, a multi-pattern microphone permits you some control over the proximity effect. As an example, if you would like more low-end from a somewhat thin voice, set your multi-pattern mic to the figure-8 mode for a stronger proximity effect.
Is Proximity Effect a Good Thing?
Vocalists have a tendency to like the proximity effect because it may make their voices sound “bigger,” more intimate, or more spectacular as they get in close to the microphone. This technique is usually known as “eating the mic” in the recording tongue.
By varying the space between themselves and the microphone, and their position relative to the mic’s axis, singers and voice artists have an extra tool to control the sound of their voices as a part of the performance. By understanding and utilizing the best way the mic’s frequency response changes with distance and angle, the proximity effect can work as an extension of the voice as an instrument.
That is part of a larger subject known as the microphone technique and is something that separates professional vocalists from amateurs. You possibly can improve and develop your technique by spending time around your mic of choice while utilizing studio headphones to monitor the output.
Don’t try it with loudspeakers although, unless you enjoy the sound of screaming feedback. For different acoustic sources, you may need to record or amplify in a live setting, such as drums, speaker cabinets, or different stationary instruments, you won’t want to worry about the sound supply and the mic moving around relative to one another. However, the proximity effect could be a great tool as an effective tone control, or equalizer, for the sound being captured.
When is the Proximity Effect Bad?
There are challenges with a constantly various low-frequency boost, which may sabotage your rigorously dialed mic input levels. For those who, or the voice talent, habitually dance or sway while performing, you might find it difficult to get a consistent sounding vocal.
Consistent vocal input is of major importance when you anticipate editing multiple takes together as a whole. The proximity effect may also negatively impact speech intelligibility, or make the low end of a combination dense and cluttered if it affects multiple tracks or instruments.
While you move in close to gain the benefits of the proximity effect, consider that the overall sound pressure level the mic receives will increase dramatically, and input overload or mic diaphragm breakup may cause distortion. Proximity may also make plosives (also known as “P-pops”) more of a problem.
You possibly can vary the amount of proximity effect by changing the angle of the mic relative to the sound source. Rotating a directional mic like a cardioid so it’s positioned at 90° to the sound supply means its front and rear sound-entry ports receive identical energy, regardless of sign frequency and wave-front curvature.
Partially rotating a directional mic away from the supply will reduce the proximity effect. This may also have an effect on the overall sensitivity and tonal stability, but with a typical cardioid mic, this will probably be relatively minor over a range of up to 45°.
The proximity effect is a naturally occurring phenomenon created by microphones with pressure gradient transducers. The nearer your microphone is to the source, the more pronounced the bass increase will probably be.
Bi-directional and cardioid polar patterns are probably the most susceptible, while Omni mics don’t suffer from extra low-end buildup. As with all audio applications, context is vital, so it is essential to make use of your ears and decide what works depending on the sound source you are capturing for the specified final result.
Simply by having an awareness of the proximity effect and how it sounds, you’ll identify it and choose to make use of it to your benefit or avoid it completely.