Q-SYS LF-4215-8F Flyable High Power Low-Frequency Cabinet - Dual 15-Inch 8-Ohm 99.5 Db Sensitivity

The LF-4215-8F dual 15" (381 mm) low-frequency enclosure is designed specifically for large format cinema applications. Meeting cinema requirements for extended low-frequency response differentiates these products from more conventional “rock-and-roll” woofer systems. The LF-4215-8F covers the frequency range from 35 Hertz to 1000 Hertz, depending upon the high-frequency system requirements.

The LF-4215-8F is an 8 ohm version and is designed for safe and easy suspension via M10 fly points. Heavily braced, tour grade construction provides great strength while keeping weight to a minimum.

The two custom 400 watt, 15" transducers were developed especially for cinema use. They feature extremely large 4" (100 mm) voice coils and a multi-vented pole piece to ensure cool operation, even at high power levels. Cooler temperatures increase transducer lifespan and decrease the problem of power compression at high power. An undercut pole piece ensures the voice coil operates in a Symmetrical Magnetic Gap (SMG), reducing second harmonic distortion.

The enclosure features Single Woofer Chambers (SWC), separate chambers for each transducer. In the rare event of a transducer failure, this prevents over-excursion of the remaining transducer caused by improper box loading. Large, Fully Radiused Ports (FRP) ensure smooth air flow through the ports, especially at higher power. This prevents potentially audible port turbulence noise. Both internal and external port openings are fully radiused.

With Symmetrical Port Loading (SPL), bass ports are evenly spaced on each side of the transducers, making internal pressure more uniform across the back surface of the transducer. This prevents the cone from being displaced to one side or another by unbalanced forces, reducing the chance of driving the voice coil out of the center of the gap at high power.

Sixteen M10 mounting points provide safe and secure means to suspend the enclosure via M10 forged eyebolts (not included) or user-supplied brackets. Always consult a licensed structural engineer to approve any mounting method

Features:

• “Flyable” dual-woofer screen channel speaker system
• Constructed of heavily braced, 15 mm tour-grade plywood
• Sixteen M10 fly points per enclosure for safe and easy suspension
• Common dimensions of Mid/Hi and LF enclosures facilitate easy installation in vertical or horizontal arrays

Specifications:

• Frequency Range:
  • ±3 dB: 38 – 1000 Hz
  • -10 dB: 30 – 1200 Hz usable range
• Maximum Output: 134.5 dB SPL calculated peak
• Impedance: 8Ω nominal
• Maximum Input Power:
  • 100 hours of 6 dB crest factor pink noise, 30 – 500 Hz: 800 watts
  • 2 hours of 6 dB crest factor pink noise, 30 – 500 Hz, AES method: 1000 watts
• Sensitivity (half space / watt / 1 meter):
  • 99.5 dB half space
  • 96.5 dB full space, 35 – 1000 Hz, 1 watt, 1 meter
• Transducers:
  • Two 15" (381 mm) high-efficiency, low-frequency transducers
  • Vented 4" (100 mm) copper voice coils
  • High-excursion/low-distortion design with high-power handling and low thermal and port compression
• Recommended Processing:
  • Subsonic filter below 30 Hz, >18 dB per octave
  • Maximum recommended crossover frequency: 1000 Hz
• Nominal Coverage: 135° horizontal x 50° vertical at 500 Hz
• Connectors:
  • Neutrik® speakON™ NL4
  • LF: 1+, 1-
  • No Connection: 2+, 2-
• Enclosure:
  • Heavily braced 15 mm tour-grade plywood
  • 16 M10 load-rated attachment points
• Dimensions (HWD):
  • Inches: 40" x 31.5" x 19"
  • Millimeters: 1016 mm x 800.1 mm x 482.6 mm
• Shipping Weight: 142 lb / 64.4 kg
• Net Weight: 134 lb / 60.8 kg