QSC SB-5218 User Manual

Features
• SB-5218 features dual 500 W transducers
• SB-7218 features dual 700 W transducers
• Frequency range extends to below 25 Hz when used with
the correct B6 filter
• DCM and SF-3 signal processors optionally available
• Enclosures feature vandal-resistant woofer mounting bolts
• THX™ approved for professional cinema applications
Part of the DCS Digital Cinema Speaker Series, QSC's
SB-5218 and SB-7218 subwoofers offer a unique
solution that addresses the requirements of digital
motion picture soundtracks. Featuring dual 18" low-
frequency transducers mounted in ported enclosures,
these systems extend response to the lowest audible
frequency.
The two custom 18" transducers were developed
especially for cinema use. The woofers feature
4" voice coils and vented pole pieces to ensure
cool operation, even at high power levels. Cooler
temperatures increase driver lifespan and decrease
power compression at high drive levels. Undercut pole
pieces provide a symmetrical magnetic gap, reducing
second harmonic distortion.
Enclosures are constructed of high-quality MDF
panels and feature individual woofer chambers. The
separate chamber for each transducer makes the
enclosure stronger, provides rigidity, and prevents
cone overexcursion in the rare event of a driver failure.
Enclosure "loading" is not lost for the remaining
transducer.
Large, fully radiused ports ensure smooth airflow,
especially at higher drive levels. This prevents
potentially audible port turbulence noise. Both internal
and external port openings are flared.
With symmetrical port loading, the bass ports are
evenly spaced on each side of the transducers, making
internal pressure more uniform across the back
surface of the woofer. This prevents the cone from
being displaced to one side or another by unbalanced
air pressure, reducing the chance of driving the voice
coil out of the center of the gap at high drive levels.
THX is a trademark of THX Ltd.
SB-5218/SB-7218
Specifications
1
Frequency Range
-6 dB half space
-10 dB half space
2
Maximum Output
Calculated Peak at Rated Power 135 dB
Calculated Continuous
Impedance
3
Maximum Input Power
100 hours of 6 db crest factor
IEC 268 noise spectrum
2 hours of 6 db crest factor
pink noise, 50 Hz - 20 kHz,
AES method
Recommended Amplifier Power 1600 W RMS maximum
Sensitivity 1 watt /1 meter,
half space
Transducers
Recommended Processing
Connectors
Enclosure
Dimensions (HWD)
Weight - Net
1) All frequency ranges specified refer to measured free field response (half space, 2π).
2) Calculated SPL at 1m, (half space, 2π), speaker operating at rated RMS power with pink noise within specified frequency range.
3) Maximum input power tested in accordance with IEC 268-5 recommendations, 50 Hz - 20 kHz band limiting, 6 dB signal crest factor.
Cinema Subwoofers
SB-5218
24 Hz - 100 Hz
19 Hz - 250 Hz
129 dB
4Ω nominal
800 W RMS
1000 W RMS
99.5 dB
Two 18" (457 mm) 500 W high
efficiency subwoofer transducers
featuring 4" (100 mm) copper
coils on Kapton formers
LF boost frequency = 25 Hz, Q = 2.0, Gain = +6 dB provided by QSC,
SF-3 or DCM
Barrier strip screw terminals accept up to #10 AWG stranded wire
B6 alignment, vented enclosure with summetrical port design, tuned to
25 Hz, constructed of MDF and heavily braced. Features vandal resistant
woofer mounting bolts
30" x 48" x 24"
(762 mm x 1220 mm x 610 mm)
205 lbs (93 kg)
SB-7218
22 Hz - 100 Hz
19 Hz - 250 Hz
137 dB
130 dB
4Ω nominal
1200 W RMS
1500 W RMS
2600 W RMS maximum
101 dB
Two 18" (457 mm) 700 W high
efficiency subwoofer transducers
featuring 4" (100 mm) copper
coils on Kapton formers
210 lbs (95 kg)