Boston Acoustics 251, 261 manual Specifications, Description

Specifications	251	261
Frequency Response (±3dB)	66–20,000Hz	58–20,000Hz
Recommended Amplifier Power	10–100 watts	10–100 watts
Nominal Impedance	8 ohms	8 ohms
Sensitivity [1 watt (2.83v) at 1m]	89dB	90dB
Tweeter	3⁄4" (19mm) dome	3⁄4" (19mm) dome
Bass Unit	51⁄4" (135mm) copolymer	61⁄2" (165mm) copolymer
Crossover Frequency	6500Hz	6200Hz
External Dimensions (HxW)	91⁄2 x 63⁄4" (241 x 171mm)	109⁄16 x 73⁄4" (268 x 197mm)
Mounting Hole Cutout (HxW)	83⁄4 x 53⁄4" (223 x 146mm)	97⁄8 x 71⁄8" (251 x 181mm)
Mounting Depth (from surface)	25⁄8" (67mm)	27⁄8" (73mm)

Description

Boston Designer Series speaker systems are designed to be as accurate, clean, and musical as our free-standing speakers. The unobtrusive, flush-mount design makes them ideal for installation

in walls or ceilings of rooms where space or decor make conventional speakers undesirable or inappropriate. They can also be used for the front and/or rear channels in a home theater system.

The front surface is provided with a matte white finish. The speaker can be installed as is or can be painted to match the room environment, using the supplied painting mask. The speaker grille is removable, and is made of epoxy-painted galvanized steel.

Their smooth, detailed sound comes from two highly refined driver elements: a copolymer bass unit with butyl rubber surround for powerful bass and natural midrange, and a 3⁄4-inch dome tweeter that provides outstanding clarity and articulation. The tweeter and bass unit are mounted close together in a point-source configuration for excellent imaging and extremely broad, uniform dispersion. This is important, because wide dispersion gives you the flexibility to install the speakers where they look the best (high on the walls, for example), yet still project clear sound throughout the listening area.

Both drivers are built in Boston’s state-of-the-art production facility to be within ±1dB of the labora- tory reference, perhaps the industry’s tightest tolerance.

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