Definitive Technology UIW RCS II In-Ceiling Loudspeaker

Definitive Technology UIW RCS II Reference In-Ceiling LCR Speaker

The UIW RCS II is the flagship of Definitive Technology’s Reference Architectural Series – an in-ceiling speaker engineered to do the job of a front left, centre or right channel in a high-end home cinema, not just fill in effects. Its Wave Launch baffle angles the driver array down toward the listening area, so dialogue and front-stage imaging appear to come from the screen rather than from overhead – the classic weakness of ceiling LCRs that this design exists to fix.

The array itself pairs two 5.25-inch cast-basket bass/midrange drivers and a 1-inch pure aluminium dome tweeter with two 6.5-inch planar pressure-coupled bass radiators, all inside a fully sealed Medite enclosure. Total frequency response is rated at 22 Hz to 30 kHz with 92 dB sensitivity, giving the RCS II the output and low-end depth to keep up with tower speakers in a mixed architectural system.

Key Features

• Designed for front LCR and surround duties in reference home theatres
• Wave Launch angled baffle projects the soundstage toward the seats, not the floor
• Sealed Medite enclosure: predictable performance in any ceiling, minimal sound leakage to rooms above
• Dual 5.25-inch cast-basket drivers plus dual 6.5-inch planar bass radiators
• 92 dB sensitivity – plays loud with modest amplifier power (10-250 W per channel)
• Paintable grille disappears into the ceiling

Why a Sealed Enclosure Matters In-Ceiling

Most in-ceiling speakers use the ceiling cavity itself as their enclosure, which makes performance depend on joist spacing, insulation and whatever else is in the void – and leaks sound into the room above. The RCS II’s sealed Medite cabinet fixes the enclosure volume at the factory: every installation sounds like the designer’s reference, and the sealed box keeps bass energy in the listening room. The bass radiators extend low-frequency output without a port, so there is no port noise and no opening for dust or insulation contact.

Installation Notes

The speaker needs a 14.375-inch square cut-out with 5.875 inches of depth behind the ceiling surface; a mounting template, paint mask and foam gasket are included, and an optional rough-in kit suits new construction. Definitive Technology recommends setting the AV receiver’s speaker size to Small with a 40 Hz crossover for this model. Full technical data is listed in the specifications below.