QSC Audio SC-322 specifications LF-3215Low Frequency Loudspeaker Introduction

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Cinema Loudspeaker Systems User Manual

LF-3215Low Frequency Loudspeaker

Introduction

The LF-3215 dual 15” (381mm) low frequency enclosure is designed specifically for cinema applications. Meeting cinema requirements for extended low frequency response differenti- ates the LF-3215 from more conventional “rock-and-roll” woofer systems. The LF-3215 cov- ers the frequency range from 32 Hertz to 1500 Hertz, depending upon the high frequency system requirements. With its tight spacing between woofers, the LF-3215 offers improved coupling and keeps coverage angles wide over a greater frequency range than more widely spaced designs.

The 300 watt, 15” transducers are well suited for cinema use. They feature 3” (76mm) voice coils, 120 oz.(3.4kg) ceramic magnets, and vented pole pieces to ensure cool operation. Cooler temperatures increase transducer lifespan and decrease the problem of power com- pression at high power levels. The suspension and voice coil of each transducer have been designed to provide low distortion and high impact bass at high power levels.

The enclosure is constructed of high quality medium density fiberboard panels with stiffen- ing braces on all panels and features separate woofer chambers. This prevents over-excur- sion of a transducer caused by improper box loading in the rare event of a transducer failure. The eight stiffening braces reduce panel resonance.

Both internal and external port openings are fully radiused ensuring smooth air flow at high power. This prevents audible port turbulence noise.

With symmetrical port loading, bass ports are evenly spaced on each side of the transduc- ers, 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, reduc- ing the chance of driving the voice coil out of the center of the gap at high power levels.

Three T-nuts in the top of the enclosure provide easy mounting of QSC’s HF-63 high fre- quency system, or MH-1063 mid-high frequency system.

Enclosure is not designed to be suspended, flown, or rigged. Do not sus- pend, fly, or rig this enclosure.

This product is capable of producing sound pressure levels that can perma- nently damage human hearing. Always keep sound pressure levels in the listening area below levels that can damage human hearing.

Install in accordance with QSC Audio Product’s instructions and a licensed, professional engineer. Only use attachments, mounts, accesso- ries, or brackets specified by QSC Audio Products, Inc. Refer all servicing to qualified personnel. Servicing is required when the apparatus has been damaged in any way.

WARNING! Before placing, installing, rigging, or suspending any speaker product, inspect all hardware, suspension, cabinets, transducers, brackets and associated equipment for damage. Any missing, corroded, deformed or non-load rated component could significantly reduce the strength of the installation, placement, or array. Any such condition severely reduces the safety of the installation and should be immediately corrected. Use only hardware which is rated for the loading conditions of the installation and any possible short-term unexpected overloading. Never exceed the rating of the hardware or equipment. Consult a licensed, professional engineer when any doubt or questions arise regarding a physical equipment installa- tion.

Mounting points for mid- high or high frequency system

*TD-000173-00*

TD-000173-00 rev.C © Copyright 2004, QSC Audio Products, Inc.

QSC® is a registered trademark of QSC Audio Products, Inc. “QSC” and the QSC logo are registered with the U.S. Patent and Trademark Office