Stereo Miking Techniques

Stereo sound is something that makes the listening experience more enjoyable and intuitive. Without it, the sound is not very immersive. Many things sound much better when recorded in stereo than in plain old mono. Hence, this article will take you through some stereo miking techniques that can be used to record stereo sound.

What is Stereo Miking?

For stereo Miking, the microphones are usually used in pairs. We capture differences in sound source and frequency amplitude by placing the microphone at different positions. These slight differences in the sound of both microphones make our ears perceive the sound as stereo.

Types of Stereo Miking Techniques

XY: The two microphones are aligned in the same physical plane in this technique. They are placed at an included angle between 90 to 180 degrees. The directional response of the microphones is usually cardioid, but it can also be any other polar pattern. Since the capsules are aligned in the same physical plane, there is no difference in the arrival time of both sounds. This eliminates one of the primary localization cues, i.e., arrival time. It results in an overall less realistic stereo image. This is still one of the most common stereo techniques, a powerful sound often needed.  

Spaced Pair: It is a commonly used technique that is very easy to set up. It uses two cardioid microphones pointed directly at the sound source. The only thing is that they are separated by a distance of 2 to 20 feet, depending upon the size of the source. This creates a dramatic stereo image when the sound from the two microphones is panned hard left and right. The spectrum sounds wide, hence giving true stereo sensation. Despite all the merits, there are some demerits as well:  

• The sound is not very realistic since it is too wide.
• Depending on the distance between the two microphones, there is a hollowness in the center while listening to it back. 

Mid-side (M-S): It uses one microphone (generally cardioid) pointing directly at the source. The second microphone is bidirectional, placed perpendicularly at +90 and -90 degrees on the sides. Similar to XY, the arrival times of the sound are the same (coincident). Once the sound has been recorded, the signal of the second microphone is split, and the polarity is reversed. This gets rid of phase issues. The volume ratio of the mid-side signal and side signal creates different kinds of stereo images, which can be altered according to the song's needs. This technique helps to create a realistic stereo image because there is no hole in the middle, and the overall texture is very strong.  

Blumlein: This is one of the more interesting stereo-miking techniques people use. It uses two bidirectional cardioid microphones at an included angle of 90 degrees. The use of bidirectional microphones not only captures sound from the source but also the sound of the room/hall. The placement of the microphone accounts for the wet versus dry ratio. This results in a very natural-sounding stereo with natural reverb/room sound.