• Infra-Sub unit with a single 21” long excursion woofer
  • Very high electro-acoustic transduction efficiency (excellent integration of the various domains: electrical, mechanical and acoustic).
  • The world’s most compact and lightweight subwoofer with a 21” woofer
  • Extremely high SPL (147 dB peak @ 1 m).
  • Deep, very clean infra-low frequencies (23 Hz), thanks to an impulse response with a very small ripple.
  • Highly ingenious acoustic design that ensures top performance: a hybrid waveguide indirect radiation system able to completely recover low frequency sound pressure emitted from the rear of the unit’s 21” woofer.
  • Built to be used alone or in multiples, with the utmost reduction of footprint in relation to output and SPL achieved.
  • Easy transport when used with mobile rigs, and fits easily into any permanent installation.
  • Unrivaled extension down to very low frequencies, without any noise due to turbulence caused by air passing at high speed.
  • The internally braced cabinet ensures utmost sturdiness, free from harmful sound “colouring” due to resonance; an optional trolley with sturdy smooth-running wheels facilitates transport, even on relatively uneven surfaces.
  • Best application in “live” concerts of all sizes, floor mounted and combined with other units of the same type for sound reinforcement of infra-low frequencies.
  • High-quality permanent installations in theatres, clubs, indoor sports arenas; an ideal match for all Outline loudspeaker systems and vertical line arrays.

LAB 21 HS is a loudspeaker system suited to high-quality sound reinforcement of infra-low frequencies. It comprises a NdFeB 21” long-excursion woofer magnet (6.5″ voice coil). Loading is a hybrid waveguide indirect radiation system able to completely recover low frequency sound pressure emitted from the rear of its 21” woofer, which means an increase in sensitivity of 6 dB SPL.

In other words, with the same input voltage, this system gives an additional 6 dB over the entire low frequency band compared to the same speaker used in a closed cabinet and, on average, an additional 3 dB compared to what the same speaker would give at low frequencies if used with a horn-loaded, reflex or band-pass system. The fact that the sound is generated by two masses of air moved by a single diaphragm, greatly benefiting attack velocity in the transitory frequencies, results in deep, very clean low frequencies.

Intended as a complete system, the LAB 21 HS ensures very high electro-acoustic transduction efficiency, thanks to its excellent integration of the mechanical and acoustic domains. The coordination of these aspects, along with the dedicated amplifier (Outline T Eleven), enables the maximum energy transfer and output power control fully respecting input signals’ dynamics.

LAB 21 HS has a frequency range at -10 dB of 23 Hz to 165 Hz (maximum crossover frequency suggested: 100 Hz). Among the optionals available, a trolley ensures fast handling and efficient protection of the front of the enclosure against impacts. The black finish is in special high quality wear and weather-resistant paint. Sixteen strategically positioned integral handles facilitate handling.

Wheeled trolley/front panel protection for LAB 21 HS

FREQUENCY RESPONSE (-10 dB) 23 Hz – 165 Hz
AVERAGE DISPERSION Quasi-omnidirectional
IMPEDANCE 4 Ω (min 4.3 Ω)
POWER – WAES 2000 (8000 peak)
MAX SHORT-TERM SPL @ 1 m* 147 dB SPL (half-space)
LOUDSPEAKERS AND LOADING 1 x 21″ NdFeB woofer, hybrid waveguide indirect radiation system
WEIGHT – SINGLE UNIT 125 kg (275.5 lb)
DIMENSIONS (Net) Height: 726 mm (28 19/32″)
Width: 1126 mm (44 11/32″)
Depth: 820 mm (32 9/32″)
* calculated using +10 dB crest-factor signal