Polk Audio Reserve R350 Slim Centre Speaker Midnight Black

The Polk Audio Reserve R350 is the slim, wall-mountable centre channel in Polk’s Reserve Series — a nine-strong range engineered around the brand’s Pinnacle Ring Radiator tweeter and Turbine Cone woofer technologies. Where the standard Reserve R300 and R400 centre speakers use a conventional cabinet depth, the R350 is designed as a true left/centre/right speaker with a compact 141mm-tall profile that can be oriented horizontally as a centre or flipped vertically as a left or right channel. It sits between the R300 and R400 in Polk’s centre-channel hierarchy, offering four Turbine Cone drivers instead of the R300’s two, within a form factor that fits where deeper cabinets cannot.

Driver Technology

The R350’s 25mm Pinnacle Ring Radiator tweeter uses a distinctive pointed waveguide to guide high-frequency dispersion evenly across the listening area, widening the sweet spot for a more lifelike soundstage. The tweeter is Hi-Res Audio certified, extending response to 50kHz — well beyond the audible range and comfortably covering the extended high-frequency content in Dolby Atmos and DTS:X soundtracks.

Four 4-inch (100mm) Turbine Cone woofers handle the midrange and bass duties. Polk’s proprietary Turbine Cone combines a foam core with moulded turbine-geometry ridges that increase cone rigidity without adding mass, allowing the drivers to operate with greater accuracy and speed. The result is a smooth, detailed midrange with clear vocal reproduction — the primary job of any centre channel speaker.

Cabinet & Crossover

The R350 uses a fully sealed enclosure, eliminating the port turbulence that can muddy dialogue in ported centre speakers. Internal bracing follows Polk’s strategically angled approach — designed to break up standing-wave paths and eliminate panel resonances for a smooth, peak-free response. The two-way crossover network hands off between the mid-bass drivers at 1400Hz, with the Pinnacle tweeter crossing in at 2700Hz.

Installation & Versatility

At 762 × 141 × 187.5mm and 9kg, the R350 is slim enough to mount below a wall-mounted display using the integrated keyhole slots, or to sit on a low media unit without obscuring the screen. The speaker can be oriented vertically for use as a left or right channel, making it a genuinely flexible L/C/R solution. Nickel-plated 5-way binding posts accept bare wire, spade, pin, and banana-plug connections. Magnetic, acoustically transparent grilles are included for a clean aesthetic.

The Reserve R350 is compatible with Dolby Atmos, DTS:X, and IMAX Enhanced soundtracks, and pairs naturally with other Reserve Series speakers — the R100 or R200 bookshelf models as surrounds, the R900 Atmos height modules, and the R500, R600, or R700 towers as front left and right channels.