Bleed Reduction Recording Drums

Recording drums with multiple microphones inherently involves bleed between channels. The close proximity of cymbals, snare, toms, and kick drum means each microphone captures not only its target but also neighboring elements. Managing this bleed maintains mixing flexibility and prevents phase problems.

Understanding Drum Bleed

Every close microphone on a drum kit picks up sound from surrounding drums and cymbals. The snare microphone captures significant hi-hat. Tom microphones pick up cymbals above them. Kick microphones include substantial snare bleed.

This bleed can work positively, adding cohesion and natural interaction between kit elements. However, excessive bleed limits independent processing options and can create comb filtering when combined with overhead microphones capturing the same sources.

The goal involves reducing bleed to levels that don’t compromise mixing flexibility while maintaining enough natural interaction that the kit sounds like a unified instrument rather than isolated components.

Microphone Selection

Directional microphones reject sound from their off-axis angles. Cardioid patterns reduce rear pickup. Hypercardioid and supercardioid patterns provide tighter focus with even more rejection. These characteristics enable pointing the rejection toward loud bleed sources.

Dynamic microphones generally capture less cymbal bleed than condensers due to their rolled-off high-frequency response. The Shure SM57 on snare picks up less hi-hat sizzle than a condenser would in the same position.

Clip-on microphones like the Sennheiser e604 or Audix D2 mount directly on drum hardware, positioning closer to heads than stand-mounted alternatives. This proximity increases direct-to-bleed ratio.

Positioning Strategies

Positioning microphones with rejection patterns pointed toward bleed sources reduces unwanted pickup. Angling the snare microphone so its rear faces the hi-hat reduces hi-hat bleed into the snare channel.

Close positioning increases the ratio of direct sound to bleed. Moving from four inches to two inches from a drum head doubles the direct level while bleed remains relatively constant, improving the isolation ratio.

Physical barriers between drums and cymbals provide additional isolation. Cymbal felt washers, particularly when combined with smaller cymbal sizes, reduce cymbal level relative to drums. Some drummers use acrylic shields to block high-hat bleed.

Tuning and Damping

Drum sustain contributes to bleed. Long sustain from one drum continues while the microphone captures the next drum hit, creating bleed through sustained ringing.

Dampening drums reduces sustain, allowing cleaner separation between hits. Moon gels, tape, or other dampening methods control ring while maintaining attack and fundamental tone. The right balance maintains musicality while improving isolation.

Tuning affects bleed perception as well. Drums tuned to frequencies that clash create more obvious bleed than harmonically related tuning. Some drummers tune their kit to musical intervals, which makes bleed less objectionable when it does occur.

Gating Techniques

Noise gates attenuate signal below a threshold, reducing audible bleed during quiet passages. Applied to drum close microphones, gates open during hits and close between hits, removing bleed between drum strokes.

Gate settings require careful adjustment. Fast attack times ensure transients pass through unaffected. Hold and release times prevent unnatural cutoffs. Threshold settings must distinguish between intended hits and bleed while avoiding false triggers from loud cymbals.

Sidechain filtering improves gate accuracy. High-pass filtering the sidechain signal makes the gate respond primarily to the drum’s fundamental rather than cymbal bleed. This prevents hi-hat hits from opening the snare gate.

Embracing Useful Bleed

Strategic acceptance of bleed acknowledges that drums are one instrument played simultaneously. Close microphones serve primarily to provide additional control over balance and tone, while overheads capture the unified kit sound.

Some engineers prefer minimal close miking specifically because bleed creates cohesion. Three or four carefully placed microphones often produce more natural results than extensively isolated close-mic setups.

The decision between bleed rejection and acceptance depends on genre and production style. Heavily processed modern metal requires tight isolation for sample triggering and replacement. Jazz and acoustic music often benefits from natural bleed that maintains kit interaction.