QSC SB-7218 – Dual 18-Inch Cinema Subwoofer (High Output)

Product Overview

The QSC SB-7218 is a high-output dual-18-inch behind-screen cinema subwoofer from the DCS Digital Cinema Series, engineered for the demands of digital motion-picture soundtracks. Its ported enclosure and custom transducers extend response to the lowest audible frequencies for large auditoriums.

THX-approved and built with cinema-specific 18-inch drivers, the SB-7218 delivers high-level, low-distortion bass with long-term reliability.

Product Description

The SB-7218 features dual 18-inch low-frequency transducers, rated 700 W each, mounted in a ported enclosure. The custom woofers were developed specifically for cinema use, with 4-inch voice coils and vented pole pieces that keep the motor cool even at high power levels for longer driver lifespan and reduced power compression.

Undercut pole pieces provide a symmetrical magnetic gap that reduces second-harmonic distortion. With the correct B6 alignment filter, frequency response extends to below 25 Hz. Enclosures feature vandal-resistant woofer mounting bolts, and QSC DCM and SF-3 signal processors are optionally available for system tuning.

As part of the QSC DCS ecosystem, the SB-7218 integrates with QSC cinema screen channels, surrounds, amplifiers, and processors. For shallower or smaller-room installations, see the QSC SB-2180.

Key Features

• Dual 700 W 18-inch transducers — Cinema-specific 18-inch woofers handle high power for demanding digital soundtracks.
• Vented pole pieces — Keep the motor cool at high drive levels, increasing driver lifespan and reducing power compression.
• Undercut pole pieces — Provide a symmetrical magnetic gap that reduces second-harmonic distortion.
• Extended low-frequency response — Reaches below 25 Hz when used with the correct B6 alignment filter.
• Vandal-resistant mounting — Enclosures feature vandal-resistant woofer mounting bolts for installed reliability.
• Optional signal processing — QSC DCM and SF-3 signal processors are available for system tuning.
• THX approved — THX-approved for professional cinema applications.

Typical Applications

• Auditorium
• Broadcast studio
• Multi-purpose room

Technical Specifications

Frequently Asked Questions

How low does the SB-7218 play?
With the correct B6 alignment filter, its response extends to below 25 Hz for full digital-cinema low-frequency effects.

Why are the pole pieces vented and undercut?
Vented pole pieces keep the motor cool at high power for longer life and less power compression, while undercut pole pieces create a symmetrical gap that lowers second-harmonic distortion.

What processing options are available?
QSC DCM and SF-3 signal processors are optionally available to apply the correct alignment filter and system tuning.

What warranty and support come with this subwoofer?
QSC installed loudspeakers are covered under QSC's standard limited warranty; refer to QSC's published warranty terms for the current coverage period applicable to this model. Creation Networks provides pre- and post-sale support for system design and integration questions.