Definitive Technology Demand Series Bookshelf Speakers

Three new bookshelf models were unveiled which Sound United's Mark Suskind explained are intended to replace the Studio Monitor Series. The models start with the D7 at $499/pair which feature a 4.5" woofer and 1" aluminum dome tweeter and is also ported. The D9 retails for $749/pair and has a 5.25" woofer and a 5"x9" passive radiator and 1" aluminum dome tweeter. And finally the new D11 has a 6.5" woofer and 6"x10" passive radiator and sells for $999/pair. All available since late last year.

Suskind started off explaining the new tweeter: "the first thing you'll notice is the tweeters are offset, so they are sold in matched pairs. We did a lot of research on the issue of diffraction and putting the tweeter off center mitigates the diffraction issues. With the tweeter in the middle you get these nasty frequency response abnormalities, which makes the speaker sound rough and it doesn't image precisely. Moving the dome off center eliminates these issues along with a lot work done on optimizing the faceplate to eliminate edge refraction."

There is also a waveguide that sits in front of the dust-cap of the woofer. The idea here is to find ways to simplify the crossover needs which in turn allows more efficiency and less phase anomalies. Suskind notes that "the waveguide essentially extends the frequency response of the driver both on and off axis, which allows to do less in the crossover to try to compensate for any driver issues."

The aluminum baffle on front of each speaker sits on top of the MDF box that the drivers are mounted to. "You create a composite structure," says Suskind, "from the MDF to the gasket to this solid piece of aluminum which reduces overall resonances as the materials fight each other and cancel them out by turning resonances into heat.

Finally, the D9 and D11 models sport bass radiators on their tops which increases the overall low-end response, while the smaller D7 has a port on the back. The speakers are available in a 5-step process gloss black finish right now, and gloss white is coming this spring.