The R900 is a sealed two-way height module sold as a pair. Each unit combines a 4" Turbine Cone woofer with a 0.75" Pinnacle Ring Radiator tweeter, crossed over at 2100 (as listed). It is built to carry the overhead layer of Dolby Atmos, DTS:X and IMAX Enhanced soundtracks, and it also handles Dolby Atmos height virtualization, DTS Virtual:X and DTS.

The cabinet can stand on its rubber pads on top of Reserve R700, R600, R500 or R200 speakers, or hang on a wall using the keyhole slots on the back. Frequency response and sensitivity are specified for the wall-mounted position. The drivers share components with the rest of the Reserve line, so tonal character is matched across a mixed system. An acoustically inert anti-diffraction grille is included, and the speaker is Hi-Res certified.

Connection is by a single set of nickel-plated 5-way binding posts. It suits 8, 6 or 4 ohm amplifier outputs, with 45 W to 100 W or more per channel recommended. Finishes are black, white and walnut.