Definitive Technology Demand D11 Bookshelf Speakers Black (Pair)

The Definitive Technology Demand D11 is the largest bookshelf speaker in the Demand Series, sitting above the D9 and compact D7. Where the D9 uses a 5.25-inch mid/bass driver, the D11 steps up to a 6.5-inch BDSS unit paired with a larger 152 × 254 mm oval passive bass radiator, extending usable bass response down to 44 Hz from a cabinet that remains compact enough for shelf or stand placement.

BDSS Driver Technology

The 165 mm mid/bass driver uses Definitive Technology’s Balanced Double Surround System (BDSS), a polypropylene cone design that employs two suspension surrounds rather than the conventional single surround. This arrangement distributes the restoring force more evenly across the cone, reducing rocking modes and allowing longer linear excursion for cleaner output at higher volumes.

Tweeter and Waveguide

The 25 mm annealed aluminium dome tweeter is laterally offset by 5° from the cabinet’s vertical axis. This offset geometry minimises symmetrical diffraction effects from the front baffle edges, improving stereo imaging precision. A Linear Response Waveguide surrounding the dome controls high-frequency dispersion, maintaining consistent off-axis response across a wider listening area.

Passive Bass Radiator

Rather than a rear-firing port, the D11 uses an integrated 152 × 254 mm oval passive bass radiator mounted on the rear panel. This tuned radiator extends low-frequency output while avoiding the turbulence and port noise that can occur with reflex designs at higher drive levels. The result is a −3 dB point of 61 Hz, with usable extension to 44 Hz.

Cabinet and Crossover

The cabinet is constructed from MDF with an extruded, natural bead-blasted aluminium front baffle that adds rigidity and provides a heatsink for the drivers. Internal bracing and damping materials control panel resonance. The crossover network uses audiophile-grade components including polypropylene metal-film capacitors and air-core inductors, selected to minimise signal-path losses and maintain phase coherence between drivers.

Connectivity and Placement

Each speaker is fitted with gold-plated five-way binding posts, accepting bare wire, spade connectors, banana plugs, or pin connectors. A 1/4-inch threaded insert on the base accommodates the optional ST1 Demand Series speaker stands. Two acoustically transparent magnetic grilles are included. The D11 is designed for vertical orientation only.