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Cinema Loudspeaker Systems User Manual

LF-4215Low Frequency Loudspeaker

Introduction

The LF-4215 dual 15” (381mm) low frequency enclosure is designed specifically for cinema applications. Meeting cinema requirements for extended low frequency response differenti- ates the LF-4215 from more conventional “rock-and-roll” woofer systems. The LF-4215 cov- ers the frequency range from 35 Hertz to 1000 Hertz, depending upon the high frequency system requirements. Close Coupled Woofers (CCW), with its tight spacing between woof- ers, improves coupling and keeps coverage angles wide over a greater frequency range than more widely spaced designs.

The two custom 400 watt, 15” transducers were developed especially for cinema use. They feature extremely large 4” (100mm) 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 is constructed of high quality MDF panels and features Single Woofer Cham- bers (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 trans- ducers, 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.

Three T-nuts in the top of the enclosure provide easy mounting of QSC’s HF-75 high fre- quency system, or MH-1075 mid-high 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 high or mid-high system

*TD-000141-00*

TD-000141-00 rev.D © Copyright 2003, 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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Polaroid user manual LF-4215Low Frequency Loudspeaker Introduction, MacArthur Blvd., Costa Mesa, CA, 92626 USA
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LF-4215 specifications

The Polaroid LF-4215 is a remarkable addition to the world of instant photography, designed to bring nostalgia and modern appeal together. Aimed at both amateur photographers and seasoned professionals, this camera offers a unique blend of features that makes it stand out in today’s fast-paced digital landscape.

At the heart of the LF-4215 is its robust imaging technology, which combines a high-resolution lens with a powerful image sensor. This allows for vibrant, detailed photos with the characteristic Polaroid aesthetic. The camera uses a unique film format that delivers rich colors and striking contrasts, reminiscent of the iconic Polaroid prints from the past. The LF-4215 employs a special blend of analog and digital technologies, allowing photographers to enjoy the charm of instant film without sacrificing image quality.

One of the standout features of the LF-4215 is its easy-to-use interface. With a simple control layout, users can swiftly navigate settings such as exposure, ISO, and focus. The camera also includes several pre-set shooting modes tailored for different environments, whether you’re capturing a sunny outdoor scene or a low-light setting. This flexibility invites creativity, enabling photographers to experiment with various styles and techniques.

Moreover, the LF-4215 comes equipped with a built-in flash, which ensures that your images are well-lit in any situation. The camera's viewfinder offers a bright and clear framing experience, making it easier for users to compose their shots accurately. Additionally, the LF-4215 supports multiple exposure settings, allowing for unique artistic expressions and double exposures.

Another significant characteristic of the LF-4215 includes its compact and lightweight design, making it an ideal companion for on-the-go photography. Coupled with a durable exterior, this camera is built to withstand the rigors of outdoor adventures, ensuring that users can capture memorable moments without worry.

In conclusion, the Polaroid LF-4215 is a beacon of instant photography, merging classic charm with modern technology. Its impressive features, user-friendly design, and premium imaging capabilities make it a fantastic choice for anyone looking to experience the magic of instant captures. Whether you’re documenting life’s little moments or indulging in creative photography, the LF-4215 is sure to deliver satisfying results that you'll cherish for years to come.
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