Dolby SB218 – Dual 18-Inch Cinema Subwoofer

What is the Dolby SB218?

The Dolby SB218 is a dual 18-inch, front-loaded cinema subwoofer built for the low-frequency effects (LFE) channel in Dolby Atmos, Dolby Surround 7.1 and 5.1 auditoriums. It delivers extended sub-bass and high output to every seat, with two pro-audio 18-inch drivers on 4-inch voice coils. It shares the cabinet engineering of the premium large-format Dolby SB218XL in a model sized for mainstream commercial screens. Creation Networks supplies, installs and commissions the SB218 as part of complete Dolby cinema sound systems.

How does the Dolby SB218 work?

The SB218 is a passive subwoofer that runs from an external amplifier channel with the high-pass and low-pass filtering Dolby specifies in its processing settings. Each 18-inch driver sits in its own acoustic chamber inside the cabinet, which improves performance and reliability compared with a shared enclosure. At 4 ohms the cabinet handles 1200 W at 61 Vrms and reaches 133 dB continuous and 141 dB measured peak SPL at one metre, with a frequency range of 26 Hz to 170 Hz and usable response down to 22 Hz.

In a typical Dolby Atmos room the LFE feed comes from a Dolby CP950A Atmos cinema processor or a Dolby CP950, and a Dolby Multichannel Amplifier such as the DMA16302 drives the cabinets. Dolby rates the SB218 at a 750 W measured power draw, which is the figure to use when sizing amplifier channels.

Cabinets can be stacked two high. Rubber feet and indexing recesses locate the upper unit, and threaded inserts accept the BKT.136 tie plates and BKT.FLR floor brackets (both sold separately) to couple the units together and anchor the stack to the auditorium floor. The advanced input plate uses a high-current, spring-loaded terminal block, so no crimp tools or spade lugs are needed.

What are the key features of the Dolby SB218?

• Dual 18-inch pro-audio drivers — two 18-inch woofers with 4-inch voice coils and FEM-optimized ferrite motors and suspensions deliver deep, high-output LFE.
• Independent driver chambers — each driver has its own chamber within the cabinet for better performance and reliability.
• Tool-free input plate — the high-current, spring-loaded terminal block speeds installation with no crimp tools or spade lugs.
• Stackable cabinet — rubber feet and indexing recesses allow a stack of up to two units.
• Secure mechanical coupling — threaded inserts accept the BKT.136 tie plates and BKT.FLR floor brackets, sold separately.
• Balance-centered handles — handles placed at the balance point make unpacking and positioning the 171 lb cabinet easier.

Where is the Dolby SB218 typically used?

• Commercial cinema auditorium
• Screening room
• Auditorium
• House of worship
• Multi-purpose room

Technical Specifications

Frequently Asked Questions

Is the Dolby SB218 compatible with Dolby Atmos and the CP950A?

Yes. Dolby developed the SB218 for the LFE channel in Dolby Atmos, Dolby Surround 7.1 and 5.1 auditoriums, and it is fed from the LFE output of a Dolby cinema processor such as the CP950A or CP950 through an external amplifier channel.

Which amplifier should drive the SB218?

The SB218 is passive and presents a 4-ohm load rated at 1200 W @ 61 Vrms with a 750 W measured power draw. Dolby Multichannel Amplifiers such as the DMA32301 are a common pairing; Creation Networks sizes channels to the cabinet count during design.

Can SB218 cabinets be stacked?

Yes, up to two units per stack. Use the BKT.136 tie plates to couple the cabinets and the BKT.FLR floor brackets to anchor the stack, both sold separately, and follow the Dolby owner's manual.

How is the SB218 different from the SB218XL?

Both use dual 18-inch drivers in the same cabinet footprint. The SB218XL is the premium large-format version with 1600 W handling and 19 Hz usable response, while the SB218 is rated at 1200 W with 22 Hz usable response.

What warranty and support come with the SB218?

The SB218 is covered by Dolby's manufacturer warranty, and Creation Networks confirms the current terms with your quote. Our engineers design, install, tune and support Dolby cinema systems; browse the Dolby Professional collection and request a quote from Creation Networks to plan your auditorium.