KROSS 21SUB 21-inch flyable passive subwoofer

KROSS 21SUB

The Alpha Acoustics® KROSS 21SUB is the high-power low-frequency element of the KROSS line array system. With a 21″ LF driver, deep 32 Hz extension, and 1600 W RMS power handling (6400 W peak), it delivers massive impact for touring and installed sound. Use it ground-stacked or flown; deploy three or more units for cardioid arrays to control stage bleed and room modes.

  • Low-frequency extension down to 32 Hz
  • 1600 W RMS / 6400 W peak handling
  • Flyable and ground-stackable configurations
  • Cardioid operation with 3+ subs
  • Compact, installation-friendly footprint

Specialties of Speaker

  • Transducer

    1 × 21″ LF

  • Power (RMS)

    1600 W (6400 W Peak)

  • Maximum SPL

    Up to 139 dB

KROSS 21SUB detail image
  • Design

    Passive, flyable, ported

  • Frequency Response

    32 Hz – 200 Hz

  • Finish

    Black, Custom RAL colors

Specifications

Electroacoustic

  • Transducer1 × 21″ LF
  • Frequency Response32 Hz – 200 Hz
  • Sensitivity100 dB
  • Maximum SPL139 dB
  • Power (RMS/Peak)1600 W / 6400 W
  • Impedance8 Ω
  • Connectors2 × NL4 SpeakON

Design

  • TypePassive flyable subwoofer (ported)
  • EnclosureMulti-layer birch plywood
  • ProtectionBall-proof reinforced grille
  • FinishBlack, Custom RAL colors

Physical

  • Dimensions (W×D×H)700 × 808 × 608 mm
  • Weight69 kg

Downloads

Documents

Suggested Amplifiers

DAMP 2.2800HD

DAMP 2.2800HD

2 × 2800 W touring amplifier with DSP

  • In-built DSP & FIR
  • 4Ω, 8Ω
  • Class-D with PFC
  • 96 kHz / 24-bit AD/DA
  • +18 dBu max input level
  • 19", 1U design
VIEW DETAILS

Move Air with KROSS 21SUB

From touring rigs to fixed installs, KROSS 21SUB brings thunderous, controlled low-end. Fly it, stack it, and deploy cardioid arrays for precision bass where you need it.

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Alpha Acoustics Speaker