QSC SB-5218 User manual

*TD-000150-00*
Cinema Loudspeaker Systems User Manual
SB-5218 and SB-7218 Dual-18” Subwoofers
Introduction
The SB-5218 and SB-7218 are specially designed cinema subwoofers, featuring dual 500
and 700 watt, respectively, 18” (460mm) low-frequency transducers mounted in ported
enclosures. The enclosures are tuned to 25 hertz and use a B6 alignment. These should be
used with the B6 boost filter option provided by the QSC SF-1 or SF-3 Subwoofer Filter mod-
ules or the QSC Digital Cinema Monitor to ensure extended response to the lowest audible
frequencies.
Meeting cinema requirements for the extended low frequency response differentiates the
SB-5218 and SB-7218 from more conventional “rock-and-roll” subwoofer systems. Their fre-
quency range extends to below 25 hertz when used with the correct B6 filter.
The two custom 500 watt (700 watt, SB-7218), 18” transducers were developed especially
for cinema use. The woofers feature 4” (100mm) voice coils and vented pole pieces to
ensure cool operation, even at high power levels. Cooler temperatures increase driver
lifespan and decrease problematic power compression at high drive levels. Undercut pole
pieces provides a Symmetrical Magnetic Gap (SMG), reducing second harmonic distortion.
Enclosures are constructed of high quality MDF panels and feature Single Woofer Chambers
(SWC). The separate chamber for each transducer makes the enclosure stronger, provides
rigidity, and prevents cone over-excursion in the rare event of a driver failure (enclosure
“loading” is not lost for the remaining transducer).
Large, Fully Radiused Ports (FRP) ensure smooth air flow through the ports, especially at
higher drive levels. 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 air pres-
sure, reducing the chance of driving the voice coil out of the center of the gap at high drive
levels.
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-000150-00 rev.A
© Copyright 2003, 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
1675 MacArthur Blvd., Costa Mesa, CA, 92626 USA
Main Number [phone] Sales & Marketing [phone] or toll free (USA only) [phone]
Customer Service(714) 957-7150 or toll free (USA only) [phone]

Connections
Normal Connection
The SB-5218/7218 has barrier strip screw ter-
minals 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-5218/7218
The terminals marker SPK2 may be used to con-
nect another SB-5218/7218 in parallel. Connect
the wires as shown in the illustration, at right.
Note: If the SB-5218/7218’s internal wiring has
been modified in any way, this may not func-
tion. 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 termi-
nals. Replace the terminal cup and mark the
enclosure with a note of the modification.
Normal Connection Example:
Parallel Connection Example:
Individual Transducer
Connection Example:

Specifications (subject to change without notice)
SB-5218 SB-7218
Frequency Range: 24 - 100 Hz (±3 dB) 22 - 100 Hertz (±3 dB)
19 - 250 Hz useable range (-10 dB) 19 - 250 Hertz useable range (-10 dB)
Maximum Output: 135 dB SPL calculated peak 137 dB SPL calculated peak
1 meter, half space, at rated rms power with 6 dB crest factor pink noise input, 25 - 250 Hertz.
129 dBA SPL calculated maximum continuous 130.5 dBA SPL calculated maximum continuous
1 meter. The dBA scale is typically used to identify sound sources which can cause permanent hearing loss.
Impedance: 4 ohms, nom. (3.2 @ 25 Hz., 62 @ 50 Hz.) 4 ohms, nom. (3.2 @ 27 Hz., 28 @ 48 Hz.)
Maximum Input Power:
100 hours of 6 dB crest factor 800 watts rms 1200 watts rms
pink noise, 25 - 250 Hertz
2 hours of 6 dB crest factor 1000 watts rms 1500 watts rms
pink noise, 25 - 250 Hertz, AES method
Recommended Amp Power: 1600 watts rms maximum 2600 watts rms maximum
Sensitivity: 99.5 dB half space 101.0 dB half space
(25 - 100 Hz, 1 watt, 1 m.) 93.5 dB full space 95.0 dB full space
Weight: 225 lbs. shipping, 205 lbs. net (102/93 kg.) 230 lbs. shipping, 210 lbs. net (104/95 kg.)
Both Models-
Nominal Coverage: Omnidirectional (80 Hz)
Recommended Processing: LF boost- freq.= 25 Hz, Q=2.0, gain= +6 dB. QSC DSP configurations are available at www.qscaudio.com. Parameters for alter-
native processing hardware are available upon request.
Connectors: Barrier strip screw terminals accept up to #10 AWG stranded wire. Four terminals: (two INPUT and two PARALLEL OUT). Driv-
ers 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.
Transducers: Two 18” (457mm) high efficiency subwoofer transducers featuring vented 4” (100mm) copper voice coils on Kapton® form-
ers. High excursion/low distortion design, with extremely high power handling, and low thermal and port compression.
Enclosure: B6 alignment, vented enclosure with symmetrical port design, tuned to 25 Hz, constructed of medium density fibreboard and
heavily braced. Features vandal resistant woofer mounting bolts.
Size: 30” wide X 48” high X 24” deep (762 mm X 1220 mm X 610 mm)

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 lim-
ited 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 war-
ranty 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:[email protected]
[email protected]
QSC Audio Products, Inc. 1675 MacArthur Boulevard Costa Mesa, California 92626 USA
©2003 “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.