QSC Audio SC-412 specifications TD-000171-00, LF-4115Low Frequency Loudspeaker Introduction

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Cinema Loudspeaker Systems User Manual

LF-4115Low Frequency Loudspeaker

Introduction

The LF-4115 15” (381mm) low frequency enclosure is designed specifically for cinema appli- cations. Meeting cinema requirements for extended low frequency response differentiates the LF-4115 from more conventional “rock-and-roll” woofer systems. The LF-4115 covers the frequency range from 33 Hertz to 1200 Hertz, depending upon the high frequency system requirements.

The custom 400 watt, 15” transducer was developed specifically for cinema use. It features a 4” (100mm) voice coil, 120 oz.(3.4kg) ceramic magnet, and a multi-vented pole piece to ensure cool operation. Cooler temperatures increase transducer lifespan and decrease the problem of power compression at high power levels. An undercut pole piece ensures the voice coil operates in a symmetrical magnetic gap, reducing second order harmonic distor- tion. The suspension and voice coil of the transducer have been designed to provide low dis- tortion and high impact bass at high power.

The enclosure is constructed of high quality medium density fiberboard panels with stiffen- ing braces on all six panels. Both internal and external port openings are fully radiused ensuring smooth air flow at higher power levels, preventing audible port turbulence.

Bass ports are symmetrically spaced on each side of the transducer, making internal pres- sure 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.

Three T-nuts in the top of the enclosure provide easy mounting of QSC’s HF-75 high fre- quency system, or MH-1063 mid-high system.

Mounting points for high or 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.

*TD-000171-00*

TD-000171-00 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