Shotgun microphones, also known as "interference tube" microphones, are long, narrow tubes with slits evenly spaced along each side and a capsule near the rear end. They are regarded as the go-to solution for getting the best audio results in each video production.
If you intend to get quality sound from your shotgun microphone, you need to first get yourself well informed of the basics of how it works.
What is a shotgun microphone?
Shotgun mics come to let the sound from in front of the microphone pass through the tube to the capsule. At the same time, sounds from the sides must enter through the slits. This brings an effect of phase cancellation that as a consequence, rejects those off-axis sounds. This is why the mics can precisely point at the source of sound while phasing out those unwanted.
What are the advantages of shotgun microphones?
It is a big challenge for video shooters to capture high-quality audio. Shotgun microphones, at this moment, showcase one of their biggest advantages, that is, their narrow pickup pattern. This is a big step up from your camcorder’s built-in mic, which, in general, has a wider pickup pattern causing more input of the surrounding sounds. Built-in mics can pick up a lot of ambient noise and wind, while shotgun mics give you clearer voice pickup.
Another advantage of shotgun mics is that they have a long reach. This would do you a good favor when you have to record at a distance. With long and narrow pickup patterns, these mics can often help isolate and record sound far away.
What are the differences between shotgun microphones and lavaliers?
Both shotgun mics and lavaliers can capture quality audio when used properly. They both are an excellent choice for dialogue, vlogging, and interviews.
Lavalier microphones are generally clipped onto the talent, which is an essential precondition for you to capture clear and quality sound. In this case, your talent is allowed to move around freely. This is ideal for shooting walk-and-talk scenes. However, there is interference that might disturb your recording. They are omnidirectional, which means that even if you mount a lav mic as close as possible to your subject, you could still be picking up distracting and unwanted background sounds.
Though there are directional lavs available, shotguns always excel for sound recording due to their more precise pickup pattern. This is a fantastic option when your talents aren’t moving around too much, or you have a dedicated boom mic operator who is able to take control of the sound recording along the way. Besides, when using a shotgun directional microphone, you don’t have to wire up every participant as you should typically do with a lavalier mic. That’s why this type of microphone is a great choice for an interview setup with many participants.
Regarding the sound captured, professional shotgun microphones can be more natural when you compare them to lavaliers.
How to get better sound from shotgun microphones?
The most crucial thing you need to do is to get your shotgun mic as close to the person speaking as possible and keep it pointed directly at your sound source. As we have said, such mics focus on the subject directly and closely in front of them, and they reject sounds from the sides and the rear.
When the shotgun mic is positioned a few feet above your talent, the best sound will come and a more crisp and clear dialogue will be heard. Because at this position, the microphone will stay pointing downwards and the noise from around the room will be off-axis. It is an emphasis on the voice and less concentration on environmental noise.
Another rule to position the microphone is that you should do your endeavor to avoid pointing your long shotgun mic at hard surfaces such as hardwood floors and brick walls when it is an indoor video shooting. Such surfaces would reflect sound waves that would cause the sound to be somehow hollow and can attenuate the effectiveness of the interference tube design. This means that more noise will come into your recording.
What about the shortcomings of shotgun microphones?
Though shotgun mics offer some great advantages, bear in mind that they can also challenge certain shoots. They also require extra equipment. A boom pole and a special shock mount are needed if you have a plan to make movements during shooting. In outdoor cases, you are expected to add the blimp or “dead cat”. In addition, you need an operator who knows how to keep shotgun mics out of your shots while keeping the mics well positioned to get the best sound results.
Shotguns are also easy to be influenced by wind noise. This is a result of their open-back capsule design. Sound blimps or a “dead cat” windshield are recommended to reduce the impact. Some even suggest using these noise suppression tools even if you’re shooting indoors.
Additionally, shotgun mics aren’t the best choice for small rooms, especially those with lots of hard surfaces. They are more ideal for outdoors and large spaces with balanced acoustics.
Tips to purchase shotgun microphones
If you are seriously considering buying the best budget shotgun microphone, make sure you really understand the information aforementioned first. Your camera equipment and your project for shooting should be the bases for the purchase. In some cases, a lavalier mic may be a better choice. If you want a mic that is versatile and applicable in a number of situations, a shotgun microphone is a better investment.