Subwoofer Technology

In 2004 L-ACOUSTICS® introduced a new diffraction model, the DED. The Distributed Edge Dipole was published in the AES journal and provides a logical, predictable methodology for low frequency sound design. The DED model describes how a part of the wave produced by the speaker spreads toward the cabinet edges where it is diffracted with group delay and phase inversion. The DED model is implemented for modeling the physics of cardioid applications and the size of enclosures.

The latest subwoofer design incorporates a vent with a progressive profile and ultra-low vibration walls for a significant gain in peak SPL, laminar airflow and drastic reduction of turbulence noise.

L-ACOUSTICS® subwoofers benefit from the latest acoustic, signal processing and component innovations and deliver an exceptional level of performance while offering multiple modes of operation, whether on the road or in fixed installations.
 
    SB15m subwoofer
    SB15P subwoofer
    SB18 subwoofer
    SB18i subwoofer
    SB18m subwoofer
    SB28 subwoofer
   

The SB18i is the fixed installation subwoofer designed for WST® line sources and coaxial systems, lowering the combined system operating range down to 32 Hz. Its compact size and streamlined rigging make it extremely well suited for flown coupled configurations with KARAi®.

The association of a specifically designed 18’’ transducer with a dual bass-reflex tuned enclosure provides exceptional impact and high sensitivity, low thermal compression and reduced distortion. The vents feature a progressive profile allowing laminar airflow and reduced turbulence noise even at the very highest operating levels. These combined properties contribute to the sonic qualities of the SB18i in terms of precision and musicality.

The control and amplification of the SB18i is managed by either the LA4 or LA8 platform. The onboard DSP filtering encompasses advanced crossover functions, system EQ, and dual thermal and over-excursion protection of the transducer. The L-ACOUSTICS® amplified controllers offer the following drive modes:

• The ‘‘standard’’ mode using SB18i as a companion to KUDO®, KARAi®, KIVA-KILO, ARCS® and featuring a low-pass filter at 60 Hz ([SB18_60] preset) or closely coupled to KARAi®, ARCS® and XTi with a low-pass filter at 100 Hz ([SB18_100] preset).
• The ‘‘cardioid’’ mode using SB18i as a companion to KUDO®, KARAi®, KIVA-KILO, ARCS® and featuring a low-pass filter at 60 Hz ([SB18_60_C] preset) or closely coupled to KARAi®, ARCS® and XTi with a low-pass filter at 100 Hz ([SB18_100_C] preset).

The performance of the SB18i enclosure depends upon the choice of preset and physical system configuration. Made of high grade Baltic birch plywood, the cabinet features a pole mount socket for use with XTi or KIVA enclosures and standard M6 inserts for custom rigging options.

• 32 Hz ([SB18_100] preset)

• 136 dB ([SB18_100] preset)

• 700 W

• LF: 1 x 18’’ weather-resistant, (4’’ coil, aluminum die-cast basket, vented magnet design)
• Nominal impedance: 8 ohms

• Steel, certified for: 8 SB18i with M-BUMPi (BGV-C1 compliant)

• W x H x D: 713 x 543 x 700 mm - 28.1 x 21.4 x 27.6 in.
• Weight (net): 50 kg - 110 lbs
• Connectors: 2 x 4-point Speakon®
• Material: baltic birch plywood
• Finish: Grey-brown, RAL 8019® (SB18i) or Pure white RAL 9010® (SB18iW)
• Front: polyester powder-coated steel grill, Airnet® acoustically neutral fabric
• Rigging: steel with zinc and polyester powder dual coating

•  8XTi distibuted
•  SB18i

• 2 000 Capacity
• 2 x 4 SB18i FOH

• 1 700 seats
• 2 SB18i subwoofers behind the front line arrays provide 360° directivity for various applications