Shotgun condenser microphone, also known as "interference tube" microphone, is a long, narrow tube with slits evenly spaced along each side and a capsule near the rear end. It is 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, you need to first get yourself well informed of the basic knowledge.
Working principle
Directional shotgun condenser microphone comes to let the sound from in front of it pass through the tube to the capsule (typically a condenser). 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.
Pros & cons
Like any type of condenser microphone, shotgun mic also has its merits and drawbacks. Below are some main points. Read on to have more understanding.
Advantages - Condenser shotgun microphone capture high quality sounds even at a distance.
It is a big challenge for video shooters to capture high-quality audio. Shotgun condenser microphone, at this moment, showcases one of their biggest advantages, that is, the 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 mic can pick up a lot of ambient noise and wind, while external one gives you clearer voice pickup. That is why shotgun microphone for DSLR or camcorders stands firm on the marketplace.
Another advantage is that it has a long reach. The long and narrow shotgun condenser microphone pattern help isolate and record sound far away. This would do you a good favor when you have to record at a distance.
Disadvantages - Extra accessories are needed for better recording.
Though shotgun mic offers some great advantages, bear in mind that it can also challenge certain shoots. It also requires 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 the recording equipment out of your shot while keeping the mic well positioned to get the best sound results.
Condenser microphone shotgun is 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, XLR shotgun condenser microphone isn't the best choice for small rooms, especially those with lots of hard surfaces, and instead, more ideal for outdoors and large spaces with balanced acoustics.
When to use camera shotgun condenser microphone?
Typically speaking, a shotgun condenser microphone is always used to capture a target sound source that is somehow far away and is not allowed to be reached or miked in a close way for some reasons. For example, you want to catch the roar of a lion.
It is also expected to be applicable to voice-over work. The situation is always like this: you have no such proper setup and you urgently need a voice-over sound.
How to choose a condenser shotgun video microphone?
The most significant characteristic of a shotgun mic so far is high directionality. Other things that should be considered include high sensitivity and low self-noise. As we mentioned above, a shotgun typically is a recorder targeting the source at a certain distance. This also means that it is intended to pick up low-level signal - it is the reason why a professional shotgun microphone needs to be more highly sensitive than those used for close source pickup. Then the low-level-signal sound would be amplified to proper signal level, which is why the mic should be low in self noise.
If you have had a look at the specifications of this categorized products, you may have already found the microphones tagged as “supercardioid” or “hypercardioid”. This is a result of an interference tube that is installed in the front of the microphone capsule. The interference tube allows the microphone to separate on-axis sound from off-axis sound and compel each type of sound source to reach the capsule in a different way.
Table: SYNCO D2 VS D30 by key specifications
|
SYNCO shotgun microphone |
XLR shotgun microphone D2 |
Camera shotgun microphone D30 |
|
Polar pattern |
Hyper cardioid |
Super cardioid |
|
Frequency response |
20Hz to 20KHz |
20Hz to 20KHz |
|
Self-noise |
12dB (A-weighted) |
N/A, but signal/noise ratio equal to 82dB (1KHz at 1Pa) |
|
Sensitivity |
-32dB±3dB (1dB=1V/Pa at 1KHz) |
-24dB±2dB (1dB=1V/Pa at 1KHz) |
|
Output interface |
XLRM |
Type-C to 3.5mm |
|
Weight |
165g |
85g |
|
Price |
USD299 |
USD149 |
As we explained earlier about shotgun microphone “polar pattern”, “self-noise”, and “sensitivity”, you could make a comparison between the two SYNCO shotguns and may draw a conclusion that the SYNCO D2 is much more professional than SYNCO D30, which could also be seen by pricing - the former is double-priced compared to the latter.
However, we could not say that the SYNCO D2 is much better than SYNCO D30, because they are designed for different uses. Specifically, the SYNCO D30 is developed to be a shotgun microphone for DSLR for mobile journalists, vloggers, run-and-gun, etc., that is why it is much lighter; the SYNCO D2 is expected to be mounted on boom poles and tripods, as well as camcorders for professional film, TV, and location recording.
How to make it sound better?
Get the shotgun condenser microphone as close to the person speaking as possible and keep it pointed directly at your sound source. As we have said, it focuses on the subject directly and closely in front, and rejects sounds from the sides and the rear.
When the shotgun mic for DSLR 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.
Avoid pointing your long or mini condenser shotgun microphone 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.
Conclusion
If you are seriously considering buying the best budget shotgun condenser 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.