A400

About the A400

The Boston Acoustics A400 is a mid-1980s floorstanding loudspeaker that uses a wide, very shallow cabinet designed to sit close to or flat against the rear wall. It is a three-way, acoustic-suspension design with a single 1" tweeter, one 6" midrange driver, and two 8" woofers, with the combined cone area intended to approximate that of a single 12" woofer. The cabinet is roughly 41" high, 21" wide, and about 7.25" deep, and each speaker weighs around 65 lb. Nominal impedance is 4 ohms, rated sensitivity is about 88 dB, and specified frequency response extends to roughly 38 Hz-25 kHz. The A400 was the top-of-the-line model in Boston Acoustics' original A-series, noted for its strong off-axis performance and balanced highs and mids when properly driven by a robust amplifier.