Is a Shotgun Mic Omnidirectional? (No, here’s why)

Shotgun microphones are not omnidirectional and do not capture surrounding sounds. They’re unidirectional — designed in such a way that they capture the sound in the direction you point them. The area of capturing the sound diminishes with the length of the mic.

shotgun mic

That means the longer the microphone, the narrower their pickup pattern.

As you have to point them directly to the sound source, they got the name shotgun.

Omnidirectional mics, on the other hand, captures all the surrounding sounds. 

Shotgun Mic’s Directionality

Shotguns’ directionality refers to their capabilities of recording sources placed directly on their front side.

The volume of recording can be higher compared to sources from different directions. But, it is achievable within the target range of frequency.

On the contrary, omnidirectional mics capture sound equally from different directions. There is no noticeable effect due to the positioning of the sound source.

Moreover, manufacturers help in tuning the tube-like instrument. They adjust different parameters, like length, to apply directionality to different frequencies, especially related to the human voice.

However, the problem is that a human voice can reach the peak level within a predictable range of frequency. Environmental variables, like the acoustic properties, will focus on some tones. It can result in other complications.

You may have thought of using a highly directional mic, which deals with a single frequency range.

However, it may be bassier to sensitive sounds from different angles. Lower vocal frequencies will start bouncing off the wall. They will reach your shotgun from its side and enter a series of slots. Thus, shotgun microphones are different from omnidirectional microphones. 

How Does a Shotgun Mic Work?

Shotgun mics are highly directional microphones that need targeting the sound source for a clear recording. These mics come with a higher beam of concentration to achieve good functionality.

For that, they have their share of pros and cons. 

To record a sound in good detail, you need to point the mic directly and closer to the source. That results in a more concentrated recording with a high gain.

It can be very beneficial in situations where there is a lot of ambient noise present.

If you need to record peoples’ responses or any particular sound in a noisy atmosphere, you can simply point the mic to the source. It will cut out the external noises and stay fixed to the sound source.  

There can be situations where you aren’t able to point the mic to the source; in those cases, this type of mic is not suitable.

As they need to be close and pointed, lack of that will result in unclear recording with very little or no gain. So, if your sound source is moving, or you can’t get close to it, opt for a different mic. 

Where Can You Use a Shotgun Microphone?

These mics are useful when the sound source is pretty much stable and unidirectional. Conferences, meetings, speeches, and lectures sound very good in this type of mics.

You don’t need to hold the mic, just need to talk in front of the shotgun mic at a distance.

However, some users make this mistake. As long as you speak within a few feet, the mic will work excellently and capture the sound in good detail. 

Why are Shotgun Mics Unidirectional?

Most shotgun mics come with an interference tube design. They are much different than omnidirectional mics, which have diaphragms open on one side and almost sealed on the other side. 

Interference tube mics allow sound waves to enter the diaphragm from the other side as well. But, to do that, the soundwaves need to pass through a long tube, which has several cuts and slots in it. 

Manufacturers tune the tube and slots so that it creates a time difference between a soundwave reaching the front end and the back end of the tube. This time difference between the impulses creates an interference pattern.

Sound waves are waves of increasing and decreasing air pressure alternatively tuning the tube intelligently can bring interesting results.

Tuning them in a specific way will result in the waves interfere and cancel out each other. That is how you can optimize the tube for a certain frequency range. 

You can target different frequency ranges by varying the length of the tube and the slots cut in it. This technology makes them highly specialized and suitable for few applications. That is also the reason why shotgun mics are unidirectional and focused into a concentrated zone and frequency. 

Does This Directionality Affect the Sound?

Shotgun mics offer great sound quality, but it comes with a condition. Direction matters the most before distance, and not filling the properties can distinctively impact the sound.

The frequency limiting can also be a good factor or a bad factor. The companies make these mics adjusting the length and other parameters, like an instrument, to focus on the frequency range of a human voice in general.

This has some drawbacks. 

The human voice peaks at a predictable frequency, but the entire range can vary.

Moreover, other factors such as the ambiance, acoustic properties of a room can manipulate the sound and highlight certain frequencies than the others. That results in a more colored sound. 

Shotgun mics are responsive towards a bigger spectrum when it’s pointing to the source but can pick up lower frequencies from any angle.

So, the lower frequencies can bounce off from the backside of the mic and enter through the back and sides.

The result will boost the bass frequencies and muddy up the output, which is certainly not desirable. It also becomes significantly difficult to cut out the noise and unwanted frequencies in post-production. 

How Far Can a Shotgun Mic Work?

The length of the tube and microphone quality determines the maximum distance possible for audio recordings.

Top-end shotgun mics can capture audio from a distance of 6 to 10 feet. On the other hand, more affordable mics can only manage a distance of 3 to 4 feet for a good recording.

For human voice, they are effective up to a range of 6 to 7 feet. The sound source can determine the least possible distance for best results. 

How to Improve Sound for Unidirectional Shotgun Mics

Though we call these specific types of shotgun mics, they function more like a laser, which focuses on a point.

The sound they deliver is crisp, lively, and full of presence. However, these can be pretty sensitive to loud noises. The tube, which makes the mic unidirectional, can capture significant amount of wind noise as well for the design.

The open-back design of the mic can result in the wind reaching the diaphragm and causing wind noises. The open design keeps little pressure between the diaphragms, which elevates wind interference.

With that, they are also prone to capture shocks and bumps – little noises of your movement, sliding fingers on the mic, bone creaking, and finger cracking sounds.

Many people hold shotgun mics in their hands, which is wrong; they work better when stable. To get rid of such situations, try using a pistol grip or a specific holder if you need to hold the mic. A shock mount can be an excellent choice for that. 

Some shotgun mics have a high-pass filter for handling unwanted sounds and noises from wind and others.

These sounds generally come from the sides and the back of the microphone in mostly low frequencies. These frequencies can intervene in the recording quality. The zooming sound of a bus or a plane can interrupt while recording outside.

The high-pass filter cuts out these lower frequencies to maintain the presence and crispiness of the target sound.

A single switch can turn on the filter, which works effectively. Audio engineers prefer to keep the switch on during recording outside, especially talks and interviews. In those situations, lower frequencies don’t matter. 

What Pattern Does a Shotgun Mic Have?

Shotgun mics show a unique pattern that highly depends on unidirectionality. They show a lobar pickup pattern that functions as an extension of super-cardioid or hyper-cardioid patterns.

The interference tubes provide excellent directionality as they reside ahead of the diaphragms. The front lobe is the biggest, whereas the side and back lobes show a very small range of sensitivity. 

Are Shotgun Mics Hyper-cardioid?

Cardioid mics are capable of isolating audio from distant sources with its directional pickup pattern.

The amplitude of sensitivity describes the mic type. Hyper cardioid mics offer tremendous directional picking patterns and fantastic isolation of audio from a significant distance.

You’ll see this feature mostly in shotgun mics. 

Conclusion

Shotgun mics are excellent microphones, but it depends on a number of factors. The right way of using it can record very high-quality sound.

Otherwise, it can do a poor frequency separation job and produce a colored sound.

Your application should decide what type of shotgun mic you need.