DCS Series

Digital Cinema Speakers

SB-5218 and SB-7218 Cinema Subwoofers  

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 single 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.

FEATURES

• SB-5218 features dual 500 watt transducers
• SB-7218 features dual 700 watt 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

SPECIFICATIONS	SB-5218	SB-7218
Frequency Range 1 (-6dB, Half space) (-10dB, Half space)	24-100 Hz 19-250 Hz	22-100 Hz 19-250 Hz
Nominal Coverage	n/a	n/a
Maximum Output 2 Calculated Peak at rated power Calculated Continuous	135 dB 129 dB	137 dB 130 dB
Impedance	4 ohms nominal	4 ohms nominal
Maximum Input Power 3 (100 hours of 6db crest factor IEC 268 noise spectrum) (2 hours of 6db crest factor pink noise, 50 - 20,000 Hz, AES method) Recommended Amplifier Power	800 watts RMS 1000 watts RMS 1600 watts RMS maximum	1200 watts RMS 1500 watts RMS 2600 watts RMS maximum
Sensitivity 1 watt/1 meter, half space	99.5 dB	101 dB
Transducers	Two 18" (457mm) 500 watt high-efficiency subwoofer transducers featuring 4" (100mm) copper voice coils on Kapton formers	Two 18" (457mm) 700 watt high-efficiency subwoofer transducers featuring 4" (100mm) copper voice coils on Kapton formers
Recommended Processing	LF boost Freq. = 25 Hz Q = 2.0 Gain = +6 dB provided by QSC, SF-3 or DCM	LF boost Freq. = 25 Hz Q = 2.0 Gain = +6 dB provided by QSC, SF-3 or DCM
Connectors	Barrier strip screw terminals accept up to #10 AWG stranded wire	Barrier strip screw terminals accept up to #10 AWG stranded wire
Enclosure	B6 alignment, vented enclosure with symmetrical port design, tuned to 25 Hz, constructed of MDF and heavily braced. Features vandal resistant woofer mounting bolts.	B6 alignment, vented enclosure with symmetrical port design, tuned to 25 Hz, constructed of MDF and heavily braced. Features vandal resistant woofer mounting bolts.
Dimensions	48" wide x 30" high x 24" deep (1220mm x 762mm x 610mm)	48" wide x 30" high x 24" deep (1220mm x 762mm x 610mm)
Weight	205 lbs (93 kg)	210 lbs (95 kg)

¹ All frequency ranges specified refer to measured free field response (half space, 2pi).
² Calculated SPL at 1m, (half space, 2pi), 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.

Specifications subject to change without notice.