When you look for microphone for you footage recording, you may notice a kind of microphone called stereo microphone. In most cases, people think that stereo audio is better and more professional than mono audio. Is stereo recording always the best? Is a stereo microphone right for you? Toady let’s have a look at it. And before that, you should have a brief understanding of it.
What is stereo recording microphone?
What is a stereo microphone? It is a recording device that has two microphones built in. This enables them to record sounds in the same way that our ears do. As the two microphones record sounds at the same time, stereo mic produces stereo outputs, giving the recording depth and direction. Maybe you are confused with it since it is less used than mono microphone. So firstly, we should know how many types it consists of.
There are several ways of classifying the microphone for stereo. According to the devices that it is applied to, there are camera stereo microphone and stereo microphone for iPhone and android phones. If classified by the stereo technique, 3 types are commonly used, which are A-B, X-Y, and M-S.
- A-B: Two mics using cardioid or omnidirectional polar patterns are pointed at the same target and are apart from each other.
- X-Y: The two identical cardioid mic capsules are placed at an angle between 90-135 degrees and they coincide at a single point.
- M-S: A figure 8 mic is angled 90 degrees sideways from the target sound. The other mic is placed on top of or below the figure 8 mic, and it is focused straight at the talent.
How does it work?
So how can a stereo microphone achieve stereo recording? This results from the difference in recording, including timing and frequency balance differences.
What is timing difference? Sound from the talent will arrive at each microphone at a slightly different time since they are placed at separate locations. A stereo effect can be created with a difference of just a few milliseconds.
When it comes to difference in frequency balance, by angling the stereo mic pair in different orientations in reference to the talent, each capsule will pick up a slightly varied frequency balance. The stereo effect will be more enhanced if the angle is wider.
Pros and cons
When you make decision on whether you should buy the mic or not, it is of importance to see the merits of using it and if you can stand the shortcomings. Generally speaking, the pros and cons are as followings.
Make listeners feel on the scene
As mentioned previously, the differences in timing and frequencies make the audio stereo. The most significant benefit of utilizing a stereo microphone for android and other devices is that you can record and play back exactly what you hear in your ears. Different signals are used to record sounds from various locations. And viewers can hear the sound as if they were present at the time.
Easy to set up
Compared to using two mono microphones and arranging them to record stereo sounds, using stereo microphone is more convenient. The two microphone capsules are usually set fixedly, so you don’t need to adjust the angle, placement, etc. What you need to do is to connect it to your shooting device and put it in a nice place to capture natural and realistic sounds.
No phase interference
As is often the case, when the identical audio plays from different speakers, the two sound waves will collide. Therefore, when a mono signal is played over a stereo system, this problem occurs since the signals are identical. However, because each signal recorded with stereo pair microphone is distinct from the other, the phase interference problem between the speakers is considerably reduced.
Not so versatile
However, easy setup can lead to less versatility. You can't change the angle, arrangement, or stereo width of the two inbuilt mics because they're fixed. If the setting is inappropriate for the scene, this may have an impact on your recording.
Sensitive to noise
To better capture sounds as what it is, it is sensitive to the change of audio. Even a slight change of the mic or sound sources will be shown by the mic thus distracting listeners. Hence, you are supposed to the pay attention to the movement of anything you want to record to make sure the shooting outputs.
It's crucial to keep in mind that some listeners will use mono playback technologies such as cellphones. The left and right channels will be blended together when your stereo mix is played through a mono system.
Uses: a good solution to immersive sounds
As mentioned above, stereo microphone is good at providing a sense of place. If you are attracted by its advantages, then you can see if it fits your recording needs since each type of microphone performs well in specific scenarios. And the followings are some situations when you can use it.
Microphone stereo has a wide recording range and records sounds as what your ears hear, so it is suitable for you to record sounds from many directions and make the audience feel immersive.
For example, If you’re a fan of outdoor recording, an external stereo microphone is a must-have. When you're recording video with a camera, it's difficult to capture what the sounds are as you hear. Anything you can do to improve the presence of nature in your video clip is worthwhile. A stereo dslr microphone will allow you to hear the direction from where a bird's song is coming. The sound of an unseen animal trampling through the underbrush will be more realistic. The wind that blows through the valley will become more active.
Likewise, it is a recording microphone for music, live streaming with instruments and other activities demanding stereo sounds.
How to choose a good stereo microphone: SNR decides
Stereo microphone is more sensitive to noise. So when choosing one, signal-to-noise ratio, or SNR is the key feature to consider. What is it?
Generally speaking, SNR measures the difference in the volume between the sound that you want to record and unwanted noise. Therefore, the larger the number is, the quieter the recording will be. In most cases, an ideal SNR is required to be above 70dB, and the high end can be up to 110dB.
However, this doesn’t mean that you need to purchase a microphone with very high SNR since this kind of mic is usually expensive. In most cases, you can choose the microphone stereo according to the loudness of the target sound. Here is the reference for you.
- If the signals are 50dB or louder, 73-75dB SNR is good
- For 40dB and quieter sounds, 78+dB SNR makes sense
How to make mono microphone to stereo?
Although stereo microphone is good at providing immersive audio, there are not so many recording scenarios that require stereo mode and mono microphone is more fitted. Hence, buying a stereo microphone specially for some situations may be not affordable. How to solve the problem? Actually, a sound editing software can deal with it. Here are the tips.
- Choose a sound editing software.
- Click the software and open it. Different kinds of microphones are displayed on the left side. Just choose the one that you are using.
- Change the default setting by clicking the channel tab.
- Choose the stereo set up channel.
- Save the setting and start your stereo recording.
But what if you are shooting outsides and cannot use the software? In this case, a microphone with mono and stereo mode is really helpful. It usually comes in the type of wireless microphone, consisting of two transmitters and a receiver. And it is easy to use.
For example, if you use the SYNCO P2, you can change mono mode to stereo mode by a simple press on the button of the receiver. The switch between two modes makes it a good microphone for video recording.
A right microphone leads to successful video. If you think stereo microphone is right for you after learning some important information about it, just buy one and start your shooting.