Dual 18-inch Cinema Subwoofer


  • SB-5218 features dual 500-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
Frequency Range 1
(-6 dB, Half space)
(-10 dB, Half space)

24–100 Hz
19–250 Hz

Nominal Coverage  
Maximum Output 2
Calculated Peak at rated power
Calculated Continuous

135 dB
129 dB

Impedance 4 ohms nominal  
Maximum Input Power 3
(100 hours of 6 dB crest factor
IEC 268 noise spectrum)
(2 hours of 6 dB crest factor pink
noise, 50–20,000 Hz, AES method)
Recommended Amplifier Power

800 watts continuous

1000 watts continuous

1600 watts continuous maximum

Sensitivity 2 V at 1 meter, half space 99.5 dB  
Transducers Two 18-inch (457 mm) 500 watt
high-efficiency subwoofer transducers
featuring 4-inch (100 mm) 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
Barrier strip screw terminals accept up to #10 AWG stranded wire
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 (HWD) inches 48 × 30 × 24  
Dimensions (HWD) mm 762 x 1220 x 610  
Weight 205 lb (93 kg)  

1All frequency ranges specified refer to measured response (half space, 2 pi).
2Calculated SPL at 1 m, (half space, 2 pi), speaker operating at rated continuous power with pink noise within specified frequency range.
3Maximum input power tested in accordance with IEC 268-5 recommendations, 50 Hz–20 kHz band limiting, 6 dB signal crest factor.

Specifications are subject to change without notice.