RoomMatch® RMS218 VLF-subwoofer
RoomMatch RMS218 VLF-subwoofer

RoomMatch RMS218 VLF-subwoofer

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The RoomMatch RMS218 VLF-subwoofer is designed primarily to extend the low-frequency response of Bose RoomMatch arrays down to 25 Hz. It features dual Bose LF18 18-inch high-excursion woofers, and a V-baffle design that reduces distortion while minimizing enclosure width. The durable Baltic birch enclosure with 2-part polyurethane coating integrates with all RoomMatch modules for reliable ground-stack applications. Use the RMS218 VLF-subwoofer with RMS215 subwoofer and full-range modules to create RoomMatch 4-way systems.


Very-low-frequency subwoofer - with 30 Hz rated response (-3 dB) and 25 Hz usable response (-10 dB) for the most demanding electronic music and sound-effect program material

Dual Bose LF18 woofers 18-inch, high-excursion, 4.5-inch voice coil, neodymium-magnet transducers provide maximum performance

142 dB peak sound levels - provide balanced subwoofer performance with the largest RoomMatch array systems

V-baffle design - provides increased acoustic loading and lowers port airflow turbulence to improve sound quality, while minimizing enclosure width to allow integration with all RoomMatch modules

Recommended Bose PowerMatch PM8500 power amplifier - provides optimal power and loudspeaker DSP


  • Theaters
  • Houses of worship
  • Auditoriums
  • Performing arts venues
  • Arenas



Oslo Concert Hall

Ahmad Jamal

World Revival Church

RoomMatch used by Ahmad Jamal and Yukon Kornelius

Telus Spark Science Center

Hear the Reviews

RoomMatch & PowerMatch


Technical Summary

Frequency Range (-10 dB)
25 Hz - 250 Hz

Power Handling, Peak
6000 W (3000 W per woofer)

Sensitivity (SPL / 1 W @ 1 m)
96 dB

Calculated Maximum SPL @ 1 m, peak
Array Position (free field): 134 dB
Ground Stack (half space): 140 dB
Array Position (free field): 136 dB
Ground Stack (half space): 142 dB

Nominal Impedance
2 x 4 Ω (discrete connection per woofer)

Mechanical Diagrams

Front View

Top View

Side View

Product Codes



RoomMatch short extender bar
RoomMatch short extender bar
RoomMatch large-array frame
RoomMatch large-array frame
RoomMatch ground stack subwoofer brackets
RoomMatch ground stack subwoofer brackets
RoomMatch ground stack base kit
RoomMatch ground stack base kit
RMSFLY side-plate rigging for RMS218
RMSFLY side-plate rigging for RMS218
RoomMatch ground stack pitch brackets
RoomMatch ground stack pitch brackets
RoomMatch ground stack caster kit
RoomMatch ground stack caster kit
RoomMatch quick release pins kit
RoomMatch quick release pins kit


What is the primary advantage of RoomMatch asymmetrical array module loudspeakers?

For many room shapes, asymmetrical coverage patterns improve sound quality by reducing side-wall reflections, without the need to “yaw in” array aiming. Additionally, asymmetrical coverage patterns provide enhanced stereo soundstage when used in left/right pairs, or true left/center/right systems, for many venue shapes.

What are the available coverage patterns for full-range array modules?

RoomMatch array module loudspeakers are available in 42 coverage patterns , 20 symmetrical and 22 asymmetrical patterns, with many different horizontal and vertical coverage angle combinations available.

Why is it important to match loudspeaker coverage patterns with room dimensions?

With the Progressive Directivity Array configuration, both the horizontal and vertical coverage patterns are selected for each module in the array. Array coverage can be customized to exact room dimensions. This improves overall sound quality by reducing the unwanted room acoustic reflections that can cause frequency response dips and variations. In Progressive Directivity Arrays, narrow patterns are selected to cover the rear of the room, with progressively wider patterns selected to cover the middle and front seats in the room. The differences in module directivity index (DI) help equalize levels from the front seats to the rear seats. With Progressive Directivity Arrays, virtually any room size or shape can have great sound in every seat.

What is a Progressive Directivity Array?

A Progressive Directivity Array is an array where both horizontal and vertical coverage patterns of each module in array can be selected to provide optimal coverage customized to room dimensions, acoustics and SPL requirements. Overall sound quality is improved seat to seat, by reducing unwanted room acoustic reflections that can cause frequency response dips and variations. With 5 different vertical angles of coverage, the number of modules can be reduced for modest SPL and budget requirements, without sacrificing total vertical coverage angle or sound quality.

Are RoomMatch modules rated for outdoor installations?

No. RoomMatch modules have not been tested or rated for outdoor installations.

Can RoomMatch modules be used for portable tour sound applications?

No. RoomMatch array module loudspeakers have not been tested or rated for tour sound applications, in which daily setup and tear down are required, along with frequent long-haul transportation. With the ground stack accessories, occasional movement of the modules from storage to stage areas is acceptable.

Can I mix RoomMatch RMS215 and RMS218 subwoofer modules with full-range modules in the same array?

Yes. The subwoofer modules may be suspended using the optional RMSFLY215 or RMSFLY218 side-plate kit. The RMAFLG and RMAFSM accessory array frames accommodate both subwoofer and full-range modules.

Should I use RoomMatch RMS215 or RMS218 subwoofers in a three-way RoomMatch system?

Either subwoofer can be used in a three-way system. Since the maximum SPL is the same in their respective bandwidths, the decision of which to use will depend upon the needed frequency response, with the RMS215 usable down to 40 Hz (-10 dB) and the RMS218 usable down to 25 Hz (-10 dB).

What is the recommended power amplifier and signal processor for RoomMatch modules?

RoomMatch array modules provide optimal performance when used with Bose PowerMatch configurable power amplifiers. However, RoomMatch modules may be powered by any professional amplifier that meets the recommended power requirements. RoomMatch loudspeakers connect and configure easily to PowerMatch PM8500 and PowerMatch PM4500 amplifiers. Built-in loudspeaker and array EQ pre-sets, limiting, time delay, special array compensation filters and suitable output power ratings make these amplifiers ideal for use in designs with RoomMatch array module loudspeakers. Additionally, the Bose ControlSpace engineered sound processor also contains presets for required loudspeaker signal processing of RoomMatch modules, and can be used with power amplifiers from any manufacturer. Generic EQ, limiting and delay recommended settings are available for manual setup of other brands of DSP and amplifiers and may be downloaded from

Most 2-inch diaphragm compression drivers use crossover points of 1500 Hz or higher. How can the EMB2 compression driver use a 550 Hz crossover point without severely limiting power handling?

The EMB2 extended mid-band compression driver is designed specifically for RoomMatch loudspeakers. A new, patented phase plug allows response down to 300 Hz from a small-diaphragm driver, while lowering total harmonic distortion by reducing the compression ratio. With six EMB2 drivers in each full-range module, the combined diaphragm area is 50% greater than that of a 4-inch diaphragm driver, for improved midband response from 500 to 1000 Hz.

What is the maximum number of modules that can be used with standard rigging hardware?

Up to eight (8) modules with a 10:1 safety factor.

What is the best method to determine array room coverage and aiming?

Bose Modeler sound system software (version 6.7 or higher), which simulates the actual room acoustics, contains a new Array Design Tool to help system designers determine the optimal configuration and placement of RoomMatch arrays in a model.

Can I suspend the RoomMatch array frames from the center rail?

Yes. Due to recent modifications we have made to the array frame to increase its working load limit to the same rated limit as the other rails, you can now do permanent installations from the center rail as well.

Can single modules be suspended overhead without using an array frame?

Yes. Always use an accessory array frame or bracket to suspend RoomMatch full-range modules. However, the RMS215 and RMS218 subwoofer modules includes integrated M10 threaded inserts to allow suspension without array frames, provided the published Working Load Limits of the inserts are not exceeded.

Can the RMPULL pull-back bracket or RMBRKT surface-mount brackets be used with the RMS215 or RMS218 subwoofer module?

No. The configuration of the threaded inserts and RMSFLY plates does not allow the RMS215 or RMS218 subwoofer module to be suspended using the RMPULL pull-back or RMBRKT surface-mount brackets.

Can RoomMatch modules be used for ground stack applications?

Yes. Optional ground stack accessories are available to allow up to three (3) RoomMatch modules to be used for side and stage fill applications that require occasional movement. The ground stack accessories require at least one RMS215 or RMS218 subwoofer module be used in the ground stack array.