Полочная акустика — Definitive Technology Demand D11

The Demand D11 is a bookshelf loudspeaker in the Demand series from Definitive Technology, which also includes the D7 and D9. The design splits the band two ways, with a passive radiator hidden in the top panel, and it was priced at USD 999 per pair. The cabinet combines a gloss black finish with an aluminium fascia, and a white gloss version was also offered.

Key specs that matter

The published response is 61 Hz to 22 kHz within 3 dB, sensitivity is 90 dB at 1 W and 1 m, and nominal impedance is 8 ohm. The recommended amplifier power runs from 20 to 200 W per channel. Each speaker stands 33 cm tall, 18.4 cm wide and 31.8 cm deep and weighs about 7.7 kg. The drivers are a 6.5 inch polymer cone mid-woofer and a 1 inch aluminium dome tweeter, supported by a flat 6 x 10 inch passive radiator on the top of the cabinet under a fixed black cloth cover.

Engineering and use context

Its mid-woofer relies on what the company calls a Balanced Double Surround System, or BDSS, which suspends the cone at two points to allow greater excursion than a single surround of the same size, and a phase plug sits at its centre. The tweeter membrane is annealed and sits behind a 20/20 Wave Alignment Lens, a waveguide meant to widen off-axis dispersion. Definitive Technology mounts the tweeter asymmetrically, offset laterally by 5 degrees from the centre line, so left and right speakers are mirror images that reduce wave cancellation off the front baffle and the edges. Seen from the front, the tweeter sits at roughly the 11.45 position on the left cabinet and at 12.15 on the right, which is why the pair must be placed on the correct sides. The MDF enclosure rests on rubber strips, and the front grille attaches with magnets.

Pairing

Around the back, a double set of gold-plated terminals with removable red and black plastic caps is joined by metal jumper strips for a single cable, and taking the strips out lets owners feed the woofer and tweeter sections separately through bi-wire leads or two stereo amplifiers. The relatively high sensitivity and easy nominal load put modest integrated amplifiers and AV receivers within reach, while the upper limit of the rated power range leaves space for stronger designs.

Alternatives

The Demand D9 is a smaller two-way bookshelf speaker from the same Definitive Technology series.