Monitor Audio Twin In-Wall Subwoofer System

The Monitor Audio Twin In-Wall Subwoofer System is a complete, high-performance bass package designed for custom installation. Comprising two IWS-10 passive subwoofer drivers, two IWB-10 sealed back boxes and a single IWA-250 Class D amplifier, the system delivers powerful, controlled low-frequency output while remaining entirely concealed within standard stud walls, ceilings or floors. Within Monitor Audio’s custom installation range, the IWS-10 sits alongside the smaller ICS-8 in-ceiling subwoofer, with the twin configuration offering significantly higher output and extension for dedicated home cinema rooms and larger listening spaces.

IWS-10 Driver — RDT Flat-Panel Technology

Each IWS-10 driver uses a flat 254mm (10”) diaphragm built from Monitor Audio’s Rigid Diaphragm Technology (RDT), originally developed for the flagship Platinum loudspeaker series. RDT is a sandwich construction of C-CAM alloy bonded to a honeycomb Nomex core, producing a panel that is both exceptionally rigid and remarkably lightweight. This combination allows the diaphragm to behave as a true piston across its operating range, resisting the bending modes that afflict conventional cones and delivering tight, well-defined bass even through large excursions. The 50mm diameter voice coil sits on a black anodised aluminium former, and a large vented pole piece accelerates airflow behind the diaphragm to reduce power compression and improve heat dissipation. The driver handles 150W RMS and achieves a maximum SPL of 109.8 dB individually, or 115.8 dB when both drivers are run together.

Tri-Grip Mounting & Paintable Grille

Installation is simplified by Monitor Audio’s patented Tri-Grip clamping system. Unlike conventional dog-leg clamps, Tri-Grip uses four over-centre locking mechanisms that provide three times the surface contact area with the mounting surface, ensuring an airtight seal without the risk of the driver working loose over time. The IWS-10’s trim-less grille and frame edge are fully paintable, allowing the system to blend discreetly with any décor. The rigid die-cast ABS chassis keeps the overall mounting depth to just 92mm, making it compatible with standard wall cavities. A 280 × 280mm cut-out is all that is required.

IWB-10 Sealed Back Box

The IWB-10 is a sealed pre-construction back box designed for the IWS-10. Built from heavy-duty MDF laminated with a rugged black Sandex vinyl finish, it provides a controlled 16.5-litre internal volume that optimises the driver’s low-frequency response while reducing sound transmission to adjacent rooms. The enclosure is sized to fit between standard 14” stud spacing (16” centres) and is supplied with adjustable steel fixing brackets for secure mounting before plastering or dry-lining. Pre-wired with external push-type terminals, the IWB-10 simplifies cable routing during the first-fix stage of construction.

IWA-250 Class D Amplifier

The IWA-250 is a dedicated subwoofer amplifier housed in a slim, robust 1U rack-mount steel case. Its Class D output stage, driven by a switch-mode power supply with integrated DSP, delivers up to 250W into 4 ohms — comfortably driving both IWS-10 drivers in the twin system. Three EQ presets (Music, Movie and Impact) allow the tonal character to be matched to the content, while a cabinet switch calibrates the amplifier’s drive characteristics for use with or without the IWB-10 back box. A variable crossover (40–120 Hz at 24 dB/octave) and 0°/180° phase switch provide full integration flexibility with any AV receiver or processor. The amplifier can be triggered automatically via input signal sensing or a 12V trigger link, and draws less than 0.5W in standby (ErP certified).

Inputs & Connections

The IWA-250 accepts a stereo RCA LFE input and a balanced XLR LFE input, accommodating both consumer and professional-grade source equipment. Two pairs of binding-post speaker outputs allow connection to the twin IWS-10 drivers. A 3.5mm 12V trigger input enables remote power-on from an AV receiver or control system.