Focal 100 IWSUB8

The Focal 100 IWSUB8 represents a technical feat in the world of in-wall subwoofers. Designed to disappear completely into your walls while delivering performance worthy of much larger equipment, this passive model manages to reach down to 30 Hz despite an installation depth of only 86 millimeters. The result of Focal’s French expertise, this subwoofer adopts an atypical, elongated shape—1.3 meters tall by 35 centimeters wide—allowing perfect integration.

A vertical format that defies convention

The Focal 100 IWSUB8 abandons the traditional cubic form of subwoofers in favor of a slim, vertical design measuring 1,300 x 352 x 98 millimeters. This unusual configuration addresses a precise technical constraint: fitting into constructions that follow the 16” OC (on center) mounting standard, with 40-centimeter spacing between studs. This compatibility with North American building standards reflects Focal’s intention to offer a truly universal solution.

The installation depth limited to 86 millimeters is a technical tour de force. Whereas competing in-wall subwoofers often require substantial wall cavities, the 100 IWSUB8 can be installed in almost all standard partitions. This compactness is no accident but the result of extensive optimization of the internal acoustic loading. Despite its small volume, the enclosure maintains the parameters needed for accurate low-frequency reproduction thanks to a carefully profiled front-firing port.

Weighing 14.6 kilograms, it remains manageable for a subwoofer of this size, making installation easier. The visible part, limited to the lower area housing the driver and the port, sits flush with the drywall. A paintable magnetic grille ensures a flawless finish, enabling total visual integration with your interior decor.

Polyglass technology in the service of precision

At the heart of the 100 IWSUB8 is a 21-centimeter driver featuring Focal’s signature Polyglass cone, a technology developed since the 1980s. Crafted in the brand’s Saint-Étienne workshops, it involves applying a thin layer of glass microbeads to a cellulose pulp cone. This combination brings together the natural damping qualities of paper with the rigidity provided by glass.

The resulting stiffness index is nearly ten times that of polypropylene commonly used in the industry. This increased rigidity translates into minimal cone deformation during large excursions, preserving response linearity even at high levels. The mass-stiffness-damping ratio, tuned from the membrane’s inception, ensures a remarkably linear response across the entire reproduced frequency range.

This technology enables the 100 IWSUB8 to offer a bandwidth extending from 34 Hz to 140 Hz (±3 dB), with low-end roll-off reaching 30 Hz at -6 dB. These figures place this compact sub at the level of far bulkier traditional models. Its sensitivity of 89 dB SPL (2.83V/1m) indicates solid efficiency for a passive subwoofer, easing pairing with various types of amplification.

An optimized bass-reflex design for silence

The 100 IWSUB8’s bass-reflex architecture incorporates a front port whose internal structure has been carefully engineered. The port profile is optimized to ensure laminar airflow, eliminating turbulence that causes unwanted noise. This attention to internal aerodynamics allows the sub to operate without audible chuffing, even during the most demanding passages.

The port, positioned beneath the driver, benefits from a generous diameter to limit air velocity. This design avoids the compression effect that can occur with poorly engineered compact subs when driven hard. The front-firing port also has the advantage of projecting bass directly into the listening room, without requiring rear clearance as with rear-ported designs.

The in-wall enclosure provides effective acoustic isolation, preventing any transfer of vibration through the wall structure. This allows the 100 IWSUB8 to be installed in the same wall as the main or surround speakers without risking detrimental interactions. The cabinet’s rigidity, despite its slimness, has been calculated to eliminate any self-resonance within the useful bandwidth.

The dedicated 100 IWSUB8 Amplifier: the essential companion

Focal specifically developed the 100 IWSUB8 Amplifier to get the best out of this passive subwoofer. This amplifier delivers a maximum power of 200 watts and a continuous power of 150 watts into 4 ohms, perfectly calibrated to the driver’s characteristics. In a 19-inch rack format (1U), it integrates easily into a technical rack or an AV cabinet.

A key feature of this amplifier is its ability to power two 100 IWSUB8 subwoofers simultaneously connected in parallel. This dual configuration can effectively cover areas up to 40 square meters, or provide a more uniform bass distribution in large rooms. The nominal 8-ohm impedance of each sub allows this coupling without overloading the amplifier.

Front-panel controls include volume, phase (0°/180°), and a low-pass crossover adjustable from 20 to 250 Hz. This wide range makes integration with any type of main speakers straightforward. The built-in subsonic filter (18 dB/octave) protects the driver from potentially destructive infrasonic content. The amplifier also includes comprehensive electronic protection: dynamic power control, thermal protection, short-circuit protection, and current limiting.

Installation and compatibility: integration thought through to the last detail

Installing the 100 IWSUB8 requires preparation during pre-construction or reopening of existing partitions. The sub fits between studs spaced 40 centimeters apart (16” OC standard), a common configuration in North American construction and increasingly adopted in Europe. This standardization greatly simplifies installation without requiring complex structural modifications.

The 100 IWSUB8 integrates naturally with Focal’s entire 100 Series, including models 100 IW6, 100 IWLCR5, 100 IC6ST, 100 ICW6, 100 ICW8, and 100 ICW5. This lineup consistency ensures perfect tonal homogeneity in multichannel installations. The 100 Series speakers share the same technologies (aluminum inverted-dome tweeter, Polyglass cone), ensuring a coherent sonic signature across the spectrum.

Moisture-resistant treatment of the components allows installation in humid environments such as bathrooms, a characteristic shared with the entire 100 Series. This installation versatility opens creative possibilities for architects and installers seeking to equip atypical spaces without compromising audio quality.

Technical specifications

Acoustic design

• Passive bass-reflex subwoofer with low cutoff at 30 Hz
• 21 cm Polyglass woofer for precise, powerful bass
• Profiled internal port for optimized airflow
• Shallow-depth design for installation in walls with studs spaced 40.6 cm on-center

Acoustic performance

• Sensitivity (2.83 V / 1 m): 89 dB
• Frequency response (±3 dB): 34 – 140 Hz
• Low cutoff (-6 dB): 30 Hz

Electrical characteristics

• Nominal impedance: 8 Ω
• Recommended amplifier power: max 200 W / 4 Ω
• Compatible with paired installation using the 100 IWSUB8 amplifier

Dimensions and installation

• External dimensions (W x D x H): 352 x 98 x 1300 mm
• Cutout dimensions (W x H): 352 x 1300 mm
• Mounting depth: 86 mm
• Net weight: 14.6 kg
• Slim, paintable grille with magnetic mounting

General information

• In-wall home theater system
• Recommended pairing with in-wall / in-ceiling speakers from the Focal 100 Series
• Optimal use with the dedicated 100 IWSUB8 amplifier for maximum performance