Why does proximity effect happen

These are all solvable problems. Be sure to choose a mic that is appropriate for how loud your vocal will be. Gabriel Barletta An understanding of the proximity effect can be a useful tool in many recording and live performance situations. You can vary the amount of proximity effect by changing the angle of the mic relative to the sound source. This nullifies the proximity effect. Partially rotating a directional mic away from the source will reduce the proximity effect.

Hopefully, this knowledge serves you well. Have fun with it! Check Price. Name: Subject: Message:. SoundGuys is reader supported. When you buy through links on our site we may earn an affiliate commission.

Learn More. What is the proximity effect, and why does it occur? It isn't all bad, and can actually be a useful tool. Rating Full Article Comments. Frequently Asked Questions. All you have to do to take advantage of this low end extension is to place the source nice and close to the mic.

Hot tip: You can get an even more exaggerated version of this effect with a figure eight mic, or a multipattern mic with a figure 8 setting. The best way to do it is to use a microphone polar pattern with less pronounced proximity effect. The most obvious choice is an omnidirectional mic. You might be concerned about capturing too much extra sound while using an omni mic. Sometimes during a mix you wish you could go back in time and change how you recorded a sound in the first place. When it comes to proximity effect, one worth mentioning is TDR Proximity.

A ribbon mic, by default, has a bi-directional pickup pattern figure The directionality has to do with the time it takes for sound to travel from one side of the diaphragm to the other. The amplitude of the sound wave decreases as it travels through the air. The proximity effect is caused by the increased amplitude difference, as compared to the phase difference, of low frequencies at close distances.

The path of sound travelling on-axis from the front of the figure-8 ribbon microphone:. So any given sound wave on-axis in the front of the mic hits the front and the back of the diaphragm out-of-phase.

This phase difference causes contrasting sound pressure levels between the two sides of the diaphragm at any moment in time, causing the diaphragm to move. This is how the microphone works! Similarly, the path of sound travelling on-axis from the back of the figure-8 ribbon microphone:.

The figure-8 polar pattern is sensitive to sounds on-axis from the front and the back while it rejects sound from the sides. This allows us to focus simply on the main determining factor of the proximity effect: distance of the sound source to the microphone.

Try thinking of a sound wave as a combination of single-frequency sine waves across the frequency spectrum that are all added together to create a complex sound. Frequency is inversely proportional to wavelength.

The higher the frequency, the shorter the wavelength. The shorter the wavelength, the less distance between the peak and trough of the waveform. The distance D around the diaphragm housing is constant.

As the sound frequency increases , the wavelength decreases , offering a greater potential for the phase difference between the front and back of the diaphragm. This max displacement happens when the wavelength of the sound wave is 2D twice the distance the sound wave must travel to get from the front to the back of the diaphragm.

Considering how small microphone capsules are, this wavelength is short, so the frequency is high. Recall our distance D, in which a sound wave must travel between the front of the mic diaphragm and the back of the diaphragm. The phase difference slowly diminishes as frequencies increase above a wavelength of 2D.

Phase difference becomes less, and less of a factor as the frequency moves toward a wavelength of D. A wavelength of D means the peak would happen at both the front and back and the diaphragm. Generally speaking, a higher frequency means a larger phase difference, pressure difference, and ultimately more output from the microphone.

In fact, the natural sensitivity due to phase difference rises by 6 dB per octave! However, a frequency response like that would not sound good at all. The diaphragm is damped to decrease its frequency response by 6 dB per octave to compensate for this. The damping allows for a flatter frequency response, meaning the bass frequencies are better represented and the high frequencies are not over-represented.

There is also an amplitude difference in sound waves between the front and back of the diaphragm. Unlike the phase difference, the amplitude difference is not frequency-dependent. A variation in sound wave amplitude means a contrast in sound pressure. The proximity effect is often an issue when you record guitars the E-string is is around 80 Hz.

But for dedicated bass instruments such as kick drum, bass guitar, or upright bass, the proximity effect can be helpful to create a big fat bottom end. It is strongest on figure-8 microphones, and still pretty strong though somewhat less on cardioids.

How come? Well, there are two types of transducers: pressure transducers and pressure gradient transducers. The proximity effect occurs only on pressure gradient transducers which respond to the difference in sound pressure between the front and back of the diaphragm. Pure pressure transducers are omnidirectional, pure pressure gradient transducers are bidirectional.

Cardioid microphones, which make up the majority of models, are a mixture of pressure and pressure gradient transducers. What about multipattern microphones?