Monitor Audio In-Wall Subwoofer System

The Monitor Audio In-Wall Subwoofer System bundles three purpose-built components — the IWS-10 driver, IWB-10 back box, and IWA-250 amplifier — into a single package that delivers full-range bass from inside a standard stud wall. Sitting within Monitor Audio’s Custom Install range, the system is designed for new-build and retrofit home cinema installations where a conventional free-standing subwoofer is impractical or aesthetically undesirable.

IWS-10 In-Wall Subwoofer Driver

The IWS-10 employs a flat 254mm (10″) diaphragm built from RDT (Rigid Diaphragm Technology), a sandwich construction derived from Monitor Audio’s flagship Platinum series. Two skins of C-CAM alloy are bonded to a honeycomb Nomex core, producing a panel that is both exceptionally rigid and low in mass. The result is a driver that behaves as a true piston across its operating band, resisting the bending modes that compromise conventional cone subwoofers. A 50mm voice coil on a black anodised former drives the assembly through ±10mm of linear excursion, while a large vented pole piece accelerates air flow to reduce power compression and improve heat dissipation.

The driver is rated at 150W RMS with a frequency response of 28–120Hz and a sensitivity of 86dB (1W @ 1m). Impedance is 8 ohms, and a single unit is capable of 109.8dB maximum SPL — rising to 115.8dB when two are used together. The shallow 90mm mounting depth and compact 280 × 280mm cut-out allow installation in walls, ceilings, or floors. Monitor Audio’s patented Tri-Grip clamping system provides three times the sealing surface area of a conventional dog-leg clamp, ensuring an airtight fit against the mounting surface. The trim-less grille and frame edge are paintable to blend with any décor.

IWB-10 Sealed Back Box

The IWB-10 is a sealed pre-construction enclosure built from heavy-duty MDF with a rugged laminated Sandex vinyl finish. With an internal volume of 16.5 litres, it is sized to fit between standard 14″ stud bays (16″ centres) and comes supplied with adjustable steel fixing brackets for secure mounting during the first-fix stage. The sealed design provides a controlled acoustic load for the IWS-10 while simultaneously reducing low-frequency sound transmission to adjacent rooms. The box is pre-wired with external push-type terminals for straightforward connection during installation.

IWA-250 Subwoofer Amplifier

The IWA-250 is a dedicated subwoofer amplifier housed in a slim 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 at less than 1% THD+N. A single IWA-250 can power one or two IWS-10 drivers.

The crossover operates from 25Hz to a variable upper limit of 40–120Hz at 24dB per octave, with phase switchable between 0° and 180°. Three EQ presets — Music, Movie, and Impact — tailor the bass response to the programme material, while an enclosure switch calibrates the drive characteristics for use with or without the IWB-10 back box. Inputs comprise stereo RCA and balanced LFE connections plus a 12V trigger for integration with AV receivers and control systems. Auto signal sensing activates the amplifier when it detects a line-level signal above 3.5mV, returning to standby after approximately 15 minutes of silence. Standby consumption is less than 0.5W (ErP certified).