Overhead Mic Spacing: Stereo Width and Phase Coherence

Overhead mic spacing determines the stereo width and phase coherence of drum recordings. The horizontal distance between two overhead microphones affects how listeners perceive the drum kit in stereo space—from narrow, focused imaging to wide, panoramic spread. Understanding the relationship between spacing and phase guides decisions that serve both technical quality and musical goals.

Width Versus Phase: The Fundamental Trade-off

Wider microphone spacing creates wider stereo imaging. Elements positioned off-center appear more extremely panned when captured by widely-spaced microphones. This width creates impressive stereo spread but introduces potential phase problems.

Phase issues arise because widely-spaced microphones capture the same source at different times. A snare drum centered between microphones reaches both simultaneously. A floor tom positioned to one side reaches the near microphone before the far one. This timing difference creates phase cancellation at specific frequencies.

Narrow spacing reduces phase problems but narrows stereo width. When microphones sit close together, timing differences shrink, reducing cancellation. However, the resulting image may feel mono or lacking dimension.

The optimal spacing balances width goals against phase considerations, depending on specific production requirements and the room’s contribution to the overall sound.

Spaced Pair Configurations

Spaced pair (AB) overhead setups position two microphones at equal heights, spread horizontally across the kit. Typical spacing ranges from three to six feet between capsules, with the snare drum centered between them.

Wide spacing (five to six feet) creates panoramic stereo imaging where hi-hat and ride cymbal appear at opposite edges of the stereo field. Floor tom and rack toms spread across the image with distinct positioning. This approach suits productions requiring dramatic stereo width.

Moderate spacing (three to four feet) provides balanced imaging without extreme spread. The kit retains stereo character while maintaining stronger center focus. Many engineers prefer this range for its combination of width and cohesion.

Narrow spacing (under three feet) creates focused imaging approaching mono. This approach minimizes phase issues and translates well to mono playback. The trade-off is reduced sense of space and dimension.

Coincident and Near-Coincident Configurations

Coincident techniques eliminate spacing-related phase issues by placing both microphone capsules at the same point. XY configuration angles two cardioid microphones at 90-110 degrees, using directional differences rather than timing to create stereo.

XY stereo provides excellent mono compatibility since both microphones receive all sounds simultaneously. Width depends on angle—wider angles create more spread. The resulting image is typically narrower than spaced pairs but phase-coherent at all frequencies.

Near-coincident techniques like ORTF (17cm spacing at 110-degree angle) compromise between spaced pair width and coincident phase coherence. The small spacing creates minimal timing differences while the angle provides directional separation.

The Blumlein technique uses two figure-eight pattern microphones at 90 degrees, creating a different stereo perspective that captures significant room sound from the rear. This advanced technique requires excellent room acoustics to succeed.

Ensuring Center Focus

Regardless of spacing technique, the snare drum should typically appear centered in the stereo image. Positioning the snare equidistant from both overhead microphones ensures centered placement.

Measuring from the snare center to each microphone capsule verifies equal distances. Even small differences (an inch or two) can shift snare position noticeably in the stereo field. Precise measurement prevents asymmetric imaging.

Hi-hat positioning presents challenges since it sits off-center by default. Spacing decisions determine how far to the side hi-hat appears. Very wide spacing may place hi-hat uncomfortably at the edge; narrower spacing brings it closer to center.

Floor tom and ride cymbal naturally occupy opposite sides from hi-hat. The stereo image should present a balanced spread with neither side feeling heavier than the other. Drummer kit arrangement affects this balance as much as microphone spacing.

Phase Checking and Adjustment

After positioning, phase checking reveals whether spacing creates problems. Summing the stereo signal to mono exposes cancellation—if the sound thins or loses low-end in mono, phase problems exist.

Narrow spacing adjustments can improve problematic phase while maintaining reasonable width. Moving microphones inward by several inches may resolve issues without collapsing stereo image.

Time alignment in the DAW can address phase problems from fixed spacing. Delaying one channel to align arrival times at the snare restores phase coherence artificially. This technique allows wide spacing without traditional phase penalties.

Polarity flipping one channel may reveal whether simple inversion improves the combined sound. This quick check sometimes identifies optimal configuration when spacing adjustment isn’t practical.

Genre and Style Considerations

Rock and pop productions typically use moderate spacing that provides stereo spread while maintaining punch. The kick and snare should retain impact when the stereo image sums, requiring attention to phase coherence.

Jazz and classical recording often employ wider spacing or specialized stereo techniques like ORTF or Blumlein. These genres value natural acoustic presentation that wider stereo imaging supports.

Modern electronic-influenced productions may use narrow spacing or mono overheads, prioritizing precise control over ambient character. The stereo field in these productions often comes from synthesizers and effects rather than natural drum spread.

Heavy music benefits from focused overhead imaging that keeps cymbals from overwhelming the stereo field. Moderate to narrow spacing controls cymbal spread while allowing room microphones to provide ambient width.