One of the most common and easy-to-make recording techniques is to take two microphones spaced apart and positioned parallel to each other. This is called the AB technique.
This technique can be used to record a piano, a violin or any solo instrument, or even an entire orchestra. As a general rule, the space between the mics will depend on the stereo image you want to obtain. The examples below show different ways to use the AB technique to record a piano.
Using stereo mics pair spaced 20 cm close to the piano
The space of 20 cm in an AB configuration is the one that comes closest to human listening. It’s about the distance between the two ears of an adult person.
This configuration of microphones is most often placed near the instrument, whatever the directivity used (omni, cardio, etc.).
In the example below, we have placed a stereo pair of DPA 4006 spaced 20 cm apart at about 2 meters from the piano.
Miking piano with a stereo pair spaced 40 cm
In the example below, we have placed a stereo pair of DPA 4006 spaced 40 cm to about 2.80 meters from the piano. This is one of the most used configurations when you record the piano with only two microphones, as this allows you to get a wider stereo image without creating a hole due to the large spacing.
A space of 60 cm can also be used.
Get more global perception of the instrument and the room with 80 cm stereo pair
When the microphones are placed at a greater distance from the piano, it is sometimes preferable to space them 80 cm or more in order to obtain a better overall perception of the instrument and the room.
Here we have placed a stereo pair of DPA 4006 spaced 80 cm apart at about 4 or 5 meters from the piano.
Using stereo pair spaced 1 meter or more to capture full ambiance of the room
If you want a very wide stereo image, it is also possible to space the microphones 1 meter or more, depending on the sound you are looking for. However, watch out for the delay between the mics. The larger the space is, the longer the delay will be.
In this example, we have placed a stereo pair spaced 1.5 meters apart at almost 5 meters from the piano.
Most often, when the microphones are so far apart, they are used to capture the ambiance of the room. In this case, another stereo pair is placed closer to the piano to add more definition and clarity to the sound.
Explore for yourself different spacings and distances when you place the microphones. The choice will often depend on the repertoire you want to record, but also on the acoustics of the room.