Microphone proximity effect

The proximity effect in microphones is a boost in bass frequencies when the sound source moves closer to the microphone. As you move a sound source closer to the microphone the sound will get louder.

All audible frequencies will get larger, but the low-frequency ones get disproportionally larger, leading to a bass boost.

Advantages of the proximity effect

The proximity effect was obviously not designed to happen. Microphone manufacturers would ideally want a uniform flat response across the audio spectrum.

This would obviously be the best way to “capture” the sound as accurately as possible, which is what a microphone sets out to do. As with lots of side effects in audio equipment, the creative types have used these “defects” and anomalies to their advantage.

The distortion in amplifiers has long been used to enhance the sound of guitars. In a similar way, vocalists learned to use the proximity effect to their advantage. Some will just use the bass boost by permanently singing close to the microphone as that’s the sound they like.

Others use it as an effect when the performance calls for it. For instance, if there’s a section in the song, often a slower, almost talking style when the vocalist leans into the microphone for that more intimate sound.

Disadvantages of the proximity effect

Some less experienced vocalists who aren’t advertised in the ways of performance with a microphone can be hard to record. For an experienced vocalist, the microphone becomes the instrument, almost as part of the vocal sound.

An inexperienced vocalist will often move and vary the distance they are from the microphone. Not in an intentional way but one of just randomly moving around. This not only leads to a massive variation in sound level but also in frequency range due to the proximity effect.

To some extent, this can be minimised by using equalisation but this will also get rid of any intentional proximity effect. It’s best to ask an unknown vocalist if they intend to vary their distance to the microphone beforehand.

Getting close to the microphone also increases the chances of the dreaded pops of plosive mouth sounds such as “p”s or “b”s. If you have problems with plosive sounds, you’ll find a pop filter or shield will help you out.

In speech, it can make it harder to interpret and more difficult to understand.

Microphone types

Not all microphones exhibit the proximity effect or certainly not in the same amounts.

Directional microphones seem to be more prone to this effect than some others. It’s worth experimenting with the microphones you use to see hows it affects different microphones. Of all the microphones I’ve used over the years, I found the classic Shure SM58 had the largest proximity effect.

You should experiment with your microphone and get to know how it works with various sounds and with different positions. You can read all you like but it can’t compare with experience and knowing your own equipment.

The proximity effect for other instruments

This effect isn’t just a vocal thing as obviously it’s inherent in the microphone.

You can use it to your advantage while miking things up. Bass instruments are the obvious ones to profit from here. kick drums can sound so different depending on the position of the microphone. This is why experimenting with microphone placement and positioning is such a large part of capturing a “sound”.

Positioning changes of just an inch can make a huge difference to the sound you are recording. Different environments and different types of microphones all combine to produce different effects.

This is why there is no definitive instruction book as to what’s good and bad. You just have to use your experience and experiment and above all listen.

As you will find out the angle of a directional microphone also plays an important role in the sound recorded. If you point a directional microphone straight at the sound source the effect is at its maximum. Angling the microphone will lessen the effect.

Artificially creating the proximity effect

As I mentioned earlier, although it wasn’t designed, this effect has become one in the vocalist repertoire so what do you do to reproduce it?

You can obviously resort to boosting the bass frequencies but you’ll have to experiment to get something workable without it sounding unnatural. If it’s really something important you are best to get a microphone and singer to produce it as it usually sounds better and more authentic than trying to recreate it.

As is the case with lots of recording techniques. It’s always better to try and capture “that” sound at source rather than tinker and try to recreate I later!

Summing up and some other guides

As you can see the microphone proximity effect is really quite simple. It’s just an artificial base boost when you get close to the microphone.

However, as with lots of recording techniques, this simple effect can be beneficial. As you can see it can also cause problems as well. A lot depends on whether you are the vocalist or if you are the one recording.

When it comes to recording vocals check out this novel location idea. It’s now the way I record all of my vocal tracks.

If you are a beginner in recording vocals make sure you are well versed in effect usage and techniques. The right choice and use of effects can make or break a track. Check out my beginner’s guide.

For more information about recording, vocals have a look at my article on using pop shields or filters.