Velodyne SCIWDVR + SCIWBB

Velodyne SCIWDVR + SCIWBB: dual-module in-wall subwoofer

Deep bass with no visible bulk? That’s the promise delivered by this in-wall system from the SubContractor series. Velodyne has developed a radical approach here: a T‑shaped driver mounted vertically within the thickness of the wall, paired with a sealed back box. Once installed, only a narrow grille reveals the presence of a subwoofer capable of reaching down to 22 Hz.

A rectangular driver designed for in-wall integration

The core of the SCIWDVR is a patented driver with an unusual shape: a rectangular diaphragm measuring 3 x 13.25 inches (about 7.6 x 33.6 cm) mounted in a vertical “T” configuration. This geometry addresses a very specific constraint. In a standard wall, the space between studs does not exceed 9 cm in depth. A conventional circular driver with horizontal excursion would transmit its vibrations directly to the surrounding drywall. By orienting the diaphragm either up or down depending on installation, Velodyne confines the mechanical energy inside the enclosure rather than propagating it through the structure.

The 3‑inch dual‑voice‑coil and 275 oz neodymium magnet give the driver a maximum excursion of 25 mm. This is high for a driver of this cross‑section: it compensates for the reduced diaphragm area with a long throw, enabling sound pressure levels comparable to those of a 10‑inch floor subwoofer.

Two modules to simplify installation

The system consists of two separately supplied elements. The SCIWBB is the back box, a sealed enclosure with 4 mm‑thick walls, heavily damped to avoid unwanted resonances. It is fixed between wooden or metal studs, ideally before the wall surface is installed. The SCIWDVR, which contains the driver and the grille, is then connected via flexible silicone ducts.

In new construction, the installer first mounts the back box, closes the wall with drywall, then cuts the grille opening and connects the speaker module. In retrofit installations, this is still possible but requires precise stud location and the absence of conduits or pipes in the intended mounting area. The minimum stud spacing is 16 inches (40 cm), which corresponds to the North American standard but may be problematic with some European framing systems that are closer together.

Two grilles, two integration approaches

Velodyne provides two grille options. The standard grille measures 43 x 35 cm and offers direct access to the driver for maintenance or replacement. The designer grille, much more discreet (46 x 12 cm), presents only a narrow slot. However, it requires the rest of the enclosure to be set behind the wall surface with no possibility of later access without dismantling.

The choice between the two depends on the priority: maximum discretion or accessibility. Both grilles are painted white and can be repainted to match the wall.

Acoustic performance and amplification requirements

The SCIWDVR offers a frequency response of 22 to 120 Hz at -3 dB, with harmonic distortion below 5%. It is a passive subwoofer, with no built‑in amplification. Velodyne recommends the SC‑1250 amplifier from the same series, which delivers 1250 W RMS into 4 ohms (3000 W peak) and includes a DSP with automatic seven‑band EQ, adjustable low‑pass filter from 30 to 160 Hz, and presets tailored to each model in the SubContractor range.

Using another amplifier is technically possible, but the SC‑1250 includes EQ curves specific to each sub in the series. Without these corrections, the sound may lack linearity or control in the very low bass. The amplifier can drive two SCIWDVR units simultaneously, a useful configuration in large rooms or to smooth room modes.

Technical specifications

Speaker design

• Patented design with T-shaped vertical driver
  • Reduces vibrations transmitted to the walls
  • Confines mechanical energy within the enclosure
• Effective piston dimensions: 3 x 13.25 inches
• Voice coil: 3-inch dual-wound
• Magnet: 275 oz neodymium
• Maximum excursion: 25 mm
• Driver orientation: can be aimed up or down depending on installation
• Magnetic shielding: compatible with CRT displays

Modular installation system

• Two modules for easier installation
  • SCIWDVR speaker module
  • SCIWBB rear enclosure module
• Sealed rear enclosure
  • 4 mm thick construction
  • Heavily damped
• Connection via silicone rubber conduits

Dimensions and accessories

• Combined dimensions: 72 x 35.6 x 8.9 cm (without grilles)
• Standard grille: 43 x 35 cm
  • Allows access and maintenance
• Designer grille: 46 x 12 cm
  • Discreet profile
  • Requires a facing layer over the enclosure

Installation and requirements

• New construction: fix the rear enclosure between studs, install drywall, then fit the speaker and grille
• Renovation: requires precise location of studs and absence of obstacles
• Framing requirement: minimum center-to-center spacing of 16 inches (approximately 40 cm)
• Total shipping weight: 19.5 kg (2 cartons)

Acoustic performance

• Frequency response: 22 – 120 Hz (-3 dB)
• Harmonic distortion: < 5%
• Sound reproduction: precise, controlled, with clean transients