1675 MacArthur Blvd., Costa Mesa, CA, 92626 USA
Main Number (714) 754-6175 Sales & Marketing (714) 957-7100 or toll free (USA only) (800) 854-4079 Customer Service(714) 957-7150 or toll free (USA only) (800) 772-2834
Cinema Loudspeaker Systems User Manual
LF-4215 Low 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 differentiates the LF-4215 from more conventional “rock-and-roll” woofer systems. The LF-4215 covers 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 woofers, 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 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.
Three T-nuts in the top of the enclosure provide easy mounting of QSC’s HF-75 high frequency system, or MH-1075 mid-high system.
Enclosure is not designed to be suspended, flown, or rigged. Do not suspend, fly, or rig this enclosure.
This product is capable of producing sound pressure levels that can permanently 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, accessories, 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 installation.
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
Connections
Normal Connection
The LF-4215 has barrier strip screw terminals for connection. The terminals accept up to #10 AWG stranded loudspeaker wiring. Use the largest wire size and shortest wire length possible for a given installation. Observe the polarity markings and keep polarity consistent throughout the system for best performance.
Parallel Connection of Second SB-5218
The terminals marker SPK2 may be used to connect another LF-4215 in parallel. Connect the wires as shown in the illustration, at right. Note: If the LF-4215’s internal wiring has been modified in any way, this may not function. If this is the case, remove the terminal cup and verify the presence of the factory yellow jumper and blue jumper wires; remedy as required or have the loudspeaker serviced.
Individual Transducer Connection (requires modification)
The transducers are wired in parallel inside the enclosure. If individual transducer connection is required, remove the terminal cup and remove the yellow and the blue jumper wires that are connected between the SPK1 and SPK2 terminals. Replace the terminal cup and mark the enclosure with a note of the modification.
Normal Connection Example:
Parallel Connection Example:
Amplifier capable of |
driving 4 ohm loads |
Amplifier capable of |
driving 2 ohm loads |
Individual Transducer
Connection Example:
CAUTION!
Requires removal of terminal cup
and cutting of both the yellow and the blue jumper wires that connect the SPK1 and SPK2 terminals
Amplifier capable of |
driving 2 ohm loads |
LF-4215 Specifications (subject to change without notice)
Frequency Range: |
38 - 1300 Hertz (±3 dB) |
30 - 1400 Hertz useable range (-10 dB)
Nominal Coverage: |
100° horizontal X 55° vertical at 600 Hertz |
Maximum Output: |
134.5 dB SPL calculated peak, 1 meter, half space, at rated rms power with 6 dB crest factor pink noise input, 25 - 250 Hertz. |
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128.5 dBA SPL calculated maximum continuous, 1 meter. The dBA scale is typically used to identify sound sources |
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which can cause permanent hearing loss. |
Impedance: |
4 ohms nominal |
3.4 ohms minimum , 150 Hertz
25 ohms maximum, 22 Hertz
Maximum Input Power: 800 watts rms (100 hours of 6 dB crest factor pink noise, 30 - 500 Hertz)
1000 watts rms (2 hours of 6 dB crest factor pink noise, 30 - 500 Hertz, AES method) recommended amplifier power capability1600 watts rms maximum into 4 ohms (per LF-4218)
Sensitivity: |
99.5 dB half space, 93.5 dB full space, 35 - 1000 Hertz, 1 watt, 1 meter |
Recommended Processing: |
Subsonic filter below 30 Hertz, >18 dB per octave, maximum recommended crossover frequency is 1000 Hertz. QSC |
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DSP configurations are available at www.qscaudio.com. Parameters for alternative processing hardware are available |
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upon request. |
Connectors: |
Barrier strip screw terminals accept up to #10 AWG stranded wire. Four terminals: (two INPUT and two PARALLEL |
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OUT). Drivers are internally wired in parallel. For independent transducer connection, remove blue jumper wire and yel- |
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low jumper wire on internal-side of terminal cup and mark enclosure accordingly. |
Transducers: |
Two 15” (381mm) high efficiency low frequency transducers featuring vented 4” (100mm) copper voice coils on Kap- |
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ton® formers. High excursion/low distortion design, with extremely high power handling, and low thermal and port |
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compression. |
Enclosure: |
Quasi B4 alignment, ported enclosure with fully flared ports, low turbulence symmetrical port design, tuned to 36 |
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Hertz, constructed of medium density fibreboard and heavily braced. Features vandal resistant woofer mounting bolts. |
Size: |
30” wide X 35” high X 20” deep (762 mm X 889 mm X 508 mm) |
Weight: |
195 lbs. shipping, 172 lbs. net (88/78 kg.) |
SPL and Impedance vs. Frequency
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SPL 2pi |
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SPL (dB) |
SPL 4pi |
Impedance (ohms) |
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Impedance |
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Frequency (Hertz) |
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Warranty (USA only; other countries, see your dealer or distributor)
Disclaimer
QSC Audio Products, Inc. is not liable for any damage to amplifiers, or any other equipment that is caused by negligence or improper installation and/or use of this loudspeaker product.
QSC Audio Products 3 Year Limited Warranty
QSC Audio Products, Inc. (“QSC”) guarantees its products to be free from defective material and / or workmanship for a period of three (3) years from date of sale, and will replace defective parts and repair malfunctioning products under this warranty when the defect occurs under normal installation and use - provided the unit is returned to our factory or one of our authorized service stations via pre-paid transportation with a copy of proof of purchase (i.e., sales receipt). This warranty provides that the examination of the return product must indicate, in our judgment, a manufacturing defect. This warranty does not extend to any product which has been subjected to misuse, neglect, accident, improper installation, or where the date code has been removed or defaced. QSC shall not be liable for incidental and/or consequential damages. This warranty gives you specific legal rights. This limited warranty is freely transferable during the term of the warranty period.
Customer may have additional rights, which vary from state to state.
In the event that this product was manufactured for export and sale outside of the United States or its territories, then this limited warranty shall not apply. Removal of the serial number on this product, or purchase of this product from an unauthorized dealer, will void this limited warranty. Periodically, this warranty is updated. To obtain the most recent version of QSC’s warranty statement, please visit www.qscaudio.com. Contact us at 800-854-4079 or visit our website at www.qscaudio.com.
Contacting QSC Audio Products
Mailing address:QSC Audio Products, Inc. 1675 MacArthur Boulevard
Costa Mesa, CA 92626-1468 USA
Telephone Numbers:
Main Number (714) 754-6175
Sales & Marketing (714) 957-7100 or toll free (USA only) (800) 854-4079
Customer Service(714) 957-7150 or toll free (USA only) (800) 772-2834
Facsimile Numbers:
Sales & Marketing Fax(714) 754-6174
Customer Service Fax(714) 754-6173
World Wide Web:www.qscaudio.com E-mail:info@qscaudio.com service@qscaudio.com
QSC Audio Products, Inc. 1675 MacArthur Boulevard Costa Mesa, California 92626 USA ©2003, 2004, “QSC” and the QSC logo are registered with the U.S. Patent and Trademark Office. Kapton® is a registered trademark of E.I. du Pont de Nemours and Company.
1675 MacArthur Blvd., Costa Mesa, CA, 92626 EE.UU.
Número principal +1 (714) 754-6175 Ventas y Comercialización +1 (714) 957-7100 o línea sin costo (sólo para EE.UU.) +1 (800) 854-4079
Servicio al cliente +1 (714) 957-7150 o gratis (sólo EE.UU.) +1 (800) 772-2834
Manual del usuario de los sistemas de altavoces para salas de cine Altavoz de baja frecuencia LF-4215
Introducción
La caja doble de baja frecuencia de 15” (381 mm) del altavoz LF-4215 está diseñada específicamente para aplicaciones cinematográficas. El cumplimiento de los requisitos de las aplicaciones cinematográficas referentes a una respuesta extendida de baja frecuencia, es lo que distingue al altavoz LF-4215 de otros sistemas woofer tipo “rock-and-roll” más convencionales. El altavoz LF4215 cubre un intervalo de frecuencia de 35 Hertzios a 1000 Hertzios, dependiendo de los requisitos del sistema de alta frecuencia. Woofers acoplados cerrados (Close Coupled Woofers, CCW), con su espacio estrecho entre los woofers, mejora el acoplamiento y mantiene la amplitud de los ángulos de cobertura sobre un mayor intervalo de frecuencia en comparación con diseños de espacio más grande.
Los dos transductores adaptados de 400 vatios y 15” se desarrollaron especialmente para su uso en salas de cine. Tienen bobinas de voz extremadamente grandes, de 4” (100 mm), y un polo multiventilado que asegura una operación fría, incluso a niveles altos de potencia. Las temperaturas más frías aumentan la vida útil del transductor y disminuyen el problema de compresión de la potencia a niveles altos de potencia. Un polo proyectado asegura que la bobina de voz opere en un campo magnético simétrico (Symmetrical Magnetic Gap, SMG), reduciendo la segunda deformación armónica.
La caja esta construida con paneles MDF (cartón duro de densidad media) de alta calidad y tiene cámaras de woofer sencillo (Single Woofer Chambers, SWC, cámaras separadas para cada transductor). En el raro evento de falla del transductor, esto previene la excursión excesiva del transductor remanente causada por la carga inadecuada de la caja.
Los grandes puertos totalmente redondeados (Fully Radiused Ports, FRP) aseguran un flujo uniforme de aire a su través, especialmente a niveles mayores de potencia. Esto evita ruido de turbulencia en el puerto potencialmente audible. Ambas aberturas del puerto, la interna y la externa, están totalmente redondeadas.
Con la carga simétrica de los puertos (Symmetrical Port Loading, SPL), los puertos de graves están igualmente separados a cada lado de los transductores, haciendo que la presión interna sea más uniforme a través de la superficie posterior del transductor. Esto evita que el cono sea desplazado de un lado a otro por fuerzas no equilibradas, reduciendo la probabilidad de impulsar la bobina de voz fuera del centro del espacio a altos niveles de potencia.
Tres tuercas en T en la parte superior de la caja permiten el montaje fácil del sistema de alta frecuencia HF-75 o del sistema de frecuencia media alta MH-1075, ambos de QSC.
La caja no esta diseñada para montarse suspendida, en voladizo ni sobre arneses. No suspenda esta caja, no la monte en voladizo ni sobre arneses.
Este producto es capaz de producir niveles de presión del sonido que pueden causar daños permanentes al oído humano. Siempre mantenga los niveles de presión del sonido en un área de audición con un nivel menor que el que provoca daños al oído humano.
Instale de acuerdo con las instrucciones de QSC Audio Products y de un ingeniero profesional con la debida licencia. Sólo use piezas, montajes, accesorios o soportes especificados por QSC Audio Products, Inc. Refiera todo el servicio a personal calificado. Cuando el aparato haya sido dañado de alguna manera, es necesario proporcionarle servicio.
¡ADVERTENCIA! Antes de colocar, instalar, montar o suspender cualquier producto de altavoz, inspeccione todo el equipo físico, la suspensión, los armarios, los transductores, los soportes y el equipo asociado para detectar la existencia de daños.
Cualquier componente faltante, corroído, deformado, o sin carga nominal podría reducir significativamente la resistencia de la instalación, la colocación o la configuración. Cualquier condición de este tipo reduce gravemente la seguridad de la instalación y debe corregirse de inmediato. Use sólo herraje que esté clasificado para las condiciones de carga de la instalación y cualquier posible carga excesiva a corto plazo inesperada. Nunca exceda el valor nominal del equipo físico ni del dispositivo. Consulte a un ingeniero profesional con la debida licencia cuando surjan dudas o preguntas referentes a la instalación física del equipo.
Puntos de montaje para el sistema de alta frecuencia o el sistema de frecuencia media alta
TD-000141-00 rev.D © Derechos de autor 2003, 2004, QSC Audio Products, Inc.
QSC® es una marca comercial registrada de QSC Audio Products, Inc. “QSC” y el logotipo de QSC están registrados con la Oficina de Patentes y Marcas Comerciales de los Estados Unidos
Conexiones
Conexión normal
El altavoz LF-4215 tiene terminales de tornillo de barra protectora para su conexión. Los terminales aceptan cableado trenzado de hasta #10 AWG para altavoces. Use el alambre del calibre más grande y de la longitud más corta posible en cualquier instalación. Observe las marcas de polaridad y mantenga la polaridad uniforme en todo el sistema para obtener el mejor rendimiento.
Conexión en paralelo de un segundo SB-5218
Los terminales marcados SPK2 se pueden usar para conectar en paralelo otro altavoz LF-4215. Conecte los cables como se muestra en la ilustración, a la derecha. Nota: si el cableado interno de LF-4215 se ha modificado de alguna manera, es posible que no funcione. En este caso, quite la cúpula del terminal y verifique la presencia de alambres amarillos y azules de puentes instalados en fábrica; corrija el problema según se requiera, o solicite que den servicio al altavoz.
Ejemplo de una conexión normal:
Ejemplo de conexión en paralelo:
Ejemplo de la conexión
de un transductor individual:
Conexión del transductor individual (requiere modificación)
Los transductores están conectados en paralelo dentro de la caja. Si se requiere la conexión del transductor individual, quite la cúpula del terminal y quite los alambres amarillo y azul del puente que están conectados entre los terminales SPK1 y SPK2. Vuelva a colocar la cúpula del terminal y marque la caja con una nota que indique la modificación.
¡PRECAUCIÓN! Requiere des-
montar la cúpula del terminal y cortar los alambres amarillo y azul que conectan los terminales SPK1 y SPK2
Amplificador con capacidad de accionamiento de cargas de 4 ohmios
Amplificador con capacidad de accionamiento de cargas de 2 ohmios
Amplificador con capacidad de accionamiento de cargas de 2 ohmios
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