XY Stereo Recording

XY stereo recording positions two microphones with their capsules at the same point, angled apart to create directional differences that produce stereo imaging. This coincident technique provides perfect mono compatibility while capturing a focused, natural stereo picture.

Basic Configuration

The XY technique places two matched microphones with diaphragms as close together as possible, typically with one microphone positioned directly above the other and both angled outward. The angle between the microphones determines the stereo width, typically ranging from 90 to 135 degrees.

Cardioid polar patterns dominate XY applications, though hypercardioid patterns provide tighter focus with slightly different stereo characteristics. The cardioid rejection from the sides and rear reduces room ambience, making XY suitable for less-than-ideal acoustic spaces.

Matched microphones ensure consistent tonal characteristics across the stereo field. Mismatched microphones create tonal differences between left and right that can sound unnatural. Purchasing factory-matched pairs guarantees consistent specifications.

Angle Selection

The angle between microphones affects stereo width and center focus. Narrower angles around 90 degrees produce a more focused stereo image with a strong center. Wider angles approaching 135 degrees create broader imaging with less distinct center definition.

For most applications, 110 degrees provides a good starting point, balancing width and focus. Orchestral recording often uses wider angles to capture the full ensemble spread. Solo instrument recording typically uses narrower angles for more intimate imaging.

The angle choice interacts with recording distance. Closer positioning with narrower angles captures intimate detail. Greater distances with wider angles encompass broader sources naturally.

Positioning Considerations

Height and distance from the source follow general microphone placement principles adapted for the stereo configuration. The XY pair acts as a single point listening to the source, with distance determining the direct-to-ambient ratio.

Aiming the pair’s center axis at the center of the sound source ensures balanced left-right imaging. Off-center aiming shifts the stereo image, which may be intentional for asymmetric source arrangements.

Elevation affects the pickup of floor reflections and overhead ambience. Standard chest-to-head height provides natural perspective for most applications. Lower positioning captures more floor reflections, while higher positioning reduces this contribution.

Mono Compatibility

The defining characteristic of XY recording involves perfect mono compatibility. Since both microphones occupy the same point in space, all sounds arrive simultaneously at both capsules. The only differences between channels come from directional sensitivity, not timing.

When XY recordings sum to mono, no phase cancellation occurs. Frequencies don’t disappear or reinforce unpredictably as they can with spaced techniques. This makes XY ideal for broadcast applications where mono playback remains common.

Testing mono compatibility involves summing the two channels and listening for frequency changes. XY recordings should sound essentially unchanged except for the collapse of stereo width.

Application Examples

Acoustic instrument recording suits XY well. Capturing acoustic guitar, piano, or string instruments at moderate distance produces natural stereo imaging without the phase concerns of spaced techniques.

Drum overhead recording using XY provides a coherent kit image with reliable mono compatibility. The technique excels when drum tracks will be combined with separately recorded elements that might have their own stereo width.

Choir and vocal group recording benefits from XY’s focused imaging. The technique captures ensemble width while maintaining clear center definition for soloists and blended sections.

Equipment Requirements

Stereo bars designed for XY recording hold two microphones in the proper configuration. These mounting solutions position the microphones with capsules aligned and provide angular adjustment for width selection.

Some manufacturers offer dedicated XY microphones with two capsules in a single body. These purpose-built units guarantee proper alignment and eliminate the need for separate mounting hardware.

Small-diaphragm condensers dominate XY applications due to their compact form factor that allows close capsule positioning. Models like the Rode NT5 pair, AKG C451, and Neumann KM184 provide excellent XY performance.