Technics SB 7000 ()

A floor-standing linear phase speaker system built for precise acoustic alignment and flat frequency response.

Overview

The Technics SB-7000 is a 3-way, 3-speaker floor-standing system. It was the prototype of Technics' linear phase speaker series. The acoustic centers of the drivers are aligned along a vertical axis, which is how it aims for accurate sound with minimal phase distortion. It was an early use of linear phase design in consumer loudspeakers, and it targets both frequency and phase response.

Specifications

Impedance	6 Ω
Output sound pressure level	93dB/W/m
Instantaneous maximum input	150W
External dimensions	480 mm (W) x 845 mm (H) x 410 mm (D)
Weight	36.0 kg (with grille)
Drivers	35 cm cone woofer, 12 cm cone midrange, 3.2 cm dome tweeter
Frequency response	40 - 20,000 Hz (±5 dB)
Crossover frequency	700 Hz, 6000 Hz

Design

The SB-7000 uses a damped bass reflex enclosure with vertically aligned drivers to get linear phase performance. The drivers are a 35 cm cone woofer, a 12 cm cone midrange and a 3.2 cm dome tweeter, mounted so their acoustic centers line up and phase interference drops. The tweeter has a square-shaped strontium ferrite magnet. The midrange and high-frequency drivers both have level controls, and those controls include anti-resonance circuits so that adjusting them doesn't degrade phase.

Context

The SB-7000 sold for ¥90,000 per unit in 1977 (¥100,000 for variants), and Technics positioned it as a high-end speaker system. It was part of a series that included the SB-7000W in white finish and the SB-7000MP in rosewood grain finish.