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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

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

The QSC Audio SC-412 is a high-performance loudspeaker designed specifically for professional audio applications. With its robust construction and advanced technologies, it delivers excellent sound quality, making it a popular choice for live performances, installations, and event spaces.

One of the standout features of the SC-412 is its powerful driver configuration. It includes two 12-inch direct-radiating woofers that provide deep, punchy bass response, complemented by a 1.75-inch exit compression driver mounted on a high-frequency horn. This configuration ensures a wide frequency range, enabling the SC-412 to reproduce everything from subtle vocal nuances to explosive rock guitar riffs with clarity and depth.

A key technology used in the SC-412 is QSC's proprietary Directivity Matched Transition (DMT) design. This advanced engineering approach ensures consistent directivity across the frequency range, providing even sound coverage in various acoustic environments. As a result, audiences experience a balanced and immersive listening experience, regardless of their position in the venue.

The cabinet construction of the SC-412 further contributes to its performance. It is built from durable, ply-birch wood and features a rugged finish, enhancing both aesthetics and durability. The enclosure is designed to minimize resonance, delivering accurate sound reproduction while ensuring that the cabinet itself does not color the audio signal. Additionally, the SC-412 includes a rear rigging point, making it easy to install in various orientations, whether flying or on a stand.

In terms of connectivity, the SC-412 features both speakON and binding post connectors, offering versatility for various setups and ensuring compatibility with a wide range of amplifiers and mixers. The loudspeaker's nominal impedance of 8 ohms allows for flexible system design and configuration.

The QSC Audio SC-412 is an excellent choice for audio professionals seeking reliability and performance. Its advanced features, like the DMT design and high-quality components, make it suitable for demanding applications in both live sound and fixed installations. With its ability to deliver powerful, clear, and consistent audio, the SC-412 stands out as a versatile solution for sound reinforcement needs. Whether used for concerts, corporate events, or permanent installations, it delivers the quality and reliability that audio professionals have come to expect from QSC.
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