QSC Audio LF-3215 User Manual [en, de, es, fr]

1675 MacArthur Blvd., Costa Mesa, CA, 92626 USA
Main Number [phone] Sales & Marketing [phone] or toll free (USA only) [phone]
Customer Service [phone] or toll free (USA only) [phone]

Cinema Loudspeaker Systems User Manual

LF-3215 Low 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 differenti­ates the LF-3215 from more conventional “rock-and-roll” woofer systems. The LF-3215 cov­ers 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 com­pression 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 stiffen­ing braces on all panels and features separate woofer chambers. This prevents over-excur­sion of a transducer caused by improper box loading in the rare event of a transducer failure.
The eight stiffening braces reduce panel resonance.

Mounting points for mid-

high or high frequency

system

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 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 levels.

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

*TD-000173-00*

“QSC” and the QSC logo are registered with the U.S. Pa tent and Trademark Office

QSC® is a registered trademark of QSC Audio Products, Inc.

© Copyright 2004, QSC Audio Products, Inc.

TD-000173-00 rev.C

Connections

Normal Connection

The LF-3215 has barrier strip screw termi­nals for connection. The terminals accept
up to #10 AWG (5.3mm
speaker wiring. Use the largest wire size
and shortest wire length possible for the
application. Observe the polarity markings
and keep polarity consistent throughout
the system for best performance.

Parallel Connection of Second LF-3215

The terminals marker SPK2 may be used to
connect another LF-3215 in parallel. Con­nect the wires as shown in the illustration,
at right. Note: If the LF-3215’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.

2

) stranded loud-

Normal Connection Example:

Amplifier capable of
driving 4 ohm loads

Parallel Connection Example:

Amplifier capable of
driving 2 ohm loads

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.

Individual Transducer
Connection Example:

CAUTION! Requires
removal of terminal
cup and removing
both the yellow and
the blue jumper
wires that connect
the SPK1 and SPK2
terminals.

LF-3215 Specifications (subject to change without notice)

Frequency Range: 32 - 1500 Hertz (-6dB)

28 - 3300 Hertz useable range (-10dB)

Nominal Coverage: 100° horizontal X 55° vertical at 600 Hertz

Maximum Output:

Impedance: 4 ohms nominal

Maximum Input Power: 600 watts rms (8 hours of 6 dB crest factor pink noise, 40 - 400 Hertz)

Sensitivity: 98.5 dB half space, 97.5 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

Connectors: Barrier strip screw terminals accept up to #10 AWG stranded wire. Four terminals: (two INPUT and two PARALLEL

Transducers: Two 15” (381mm) high efficiency low frequency transducers featuring vented 3” (76mm) copper voice coils on Kapton®

132.5 dB SPL calculated peak, 1 meter, half space, at rated rms power with 6 dB crest factor pink noise input, 25 - 250 Hertz.

126.5 dBA SPL calculated maximum continuous, 1 meter. The dBA scale is typically used to identify sound sources
which can cause permanent hearing loss.

4.1 ohms minimum, 180 Hertz
55 ohms maximum, 21 Hertz

750 watts rms (2 hours of 6 dB crest factor pink noise, 40 - 400 Hertz)
Recommended amplifier power capability- 1200 watts rms maximum into 4 ohms (per LF-3215)

DSP configurations are available at www.qscaudio.com. Parameters for alternative processing hardware are available
upon request.

OUT). Transducers are internally wired in parallel. For independent transducer connection, remove blue jumper wire
and yellow jumper wire on internal-side of terminal cup and mark enclosure accordingly.

formers. High excursion/low distortion design, with extremely high power handling, and low thermal and port com­pression.

Enclosure: Quasi B4 alignment, ported enclosure with fully flared ports, low turbulence symmetrical port design, tuned to 36

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

SPL 2pi

SPL 4pi

SPL (dB)

Impedance (ohms)

Impedance

Frequency (Hertz)

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 [phone]
Sales & Marketing [phone] or toll free (USA only) [phone]
Customer Service(714) 957-7150 or toll free (USA only) [phone]

Facsimile Numbers:
Sales & Marketing Fax[phone]
Customer Service Fax[phone]

World Wide Web:www.qscaudio.com
E-mail:[e-mail]
[e-mail]

QSC Audio Products, Inc. 1675 MacArthur Boulevard Costa Mesa, California 92626 USA

©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.

Manual del usuario de los sistemas de altavoces para salas de cine

Altavoz de baja frecuencia LF-3215

Introducción

La caja doble de baja frecuencia de 15” (381 mm) del altavoz LF-3215 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-3215 de otros sistemas woofer tipo “rock-and-roll” más conven­cionales. El altavoz LF-3215 cubre un intervalo de frecuencia de 32 Hertzios a 1500 Hertzios,
dependiendo de los requisitos del sistema de alta frecuencia. Con su espacio estrecho entre
los woofers, el LF-3215 ofrece un mejora en 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 transductores de 300 vatios y 15” son apropiados para uso en salas de cine. Cuentan
con bobinas de voz de 3” (76 mm), imanes cerámicos de 120 onzas (3.4 kg) y polos multiven­tilados para asegurar una operación fría. Las temperaturas más frías aumentan la vida útil
del transductor y disminuyen el problema de compresión de la potencia a niveles altos de
potencia. La suspensión y la bobina de voz de cada transductor se han diseñado para brindar
una baja distorsión y graves de alto impacto a altos niveles de potencia.

La caja está construida de paneles de cartón duro mediano de alta calidad con soportes de
refuerzo en todos los paneles, y cuenta con cámaras separadas para los woofers. Esto previ­ene la excursión excesiva de un transductor causada por la carga inadecuada de la caja, en
el raro evento de falla del transductor. Los ocho soportes de refuerzo reducen la resonancia
en el panel.

Puntos de montaje para el

sistema de alta frecuencia o el

sistema de frecuencia media

alta

Ambas aberturas del puerto, la interna y la externa, están totalmente redondeadas, asegu­rando un flujo de aire uniforme a alta potencia. Esto evita ruido de turbulencia audible en el
puerto.

Con la carga simétrica de los puertos, 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-63 o del sistema de frecuencia media alta MH-1063, 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 y 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
jan dudas o preguntas referentes a la instalación física del equipo.

cuando sur-

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

© Derechos de autor 2004, QSC Audio Products, Inc.

Comerciales de los Estados Unidos

TD-000173-00 rev. C

Conexiones

Conexión normal

El altavoz LF-3215 tiene terminales de tor­nillo de barra protectora para su conexión.
Los terminales aceptan cableado trenzado
de hasta #10 AWG (5.3 mm
oces. Use el alambre de calibre más
grande y de longitud más corta posible
para la aplicación. Observe las marcas de
polaridad y mantenga la polaridad uni­forme en todo el sistema para permitir el
mejor rendimiento.

Conexión en paralelo de un segundo LF­3215

Los terminales marcados SPK2 se pueden
usar para conectar en paralelo otro altavoz
LF-3215. Conecte los cables como se
muestra en la ilustración, a la derecha.
Nota: si el cableado interno de LF-3215 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.

2

) para altav-

Ejemplo de una conexión normal:

Amplificador con capacidad de accio­namiento de cargas de 4 ohmios

Ejemplo de conexión en paralelo:

Amplificador con capacidad de
accionamiento de cargas de 2 ohmios

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.

Ejemplo de la conexión
de un transductor individual:

¡PRECAUCIÓN!
Requiere desmontar
la cúpula del termi­nal y los alambres
amarillo y azul que
conectan los termi­nales SPK1 y SPK2.