INFINITY 2000 II (1975–1979)

A four-way floorstanding speaker system with a 360-degree radiating Walsh tweeter and two top-panel options for acoustic tuning

Overview

The INFINITY 2000 II is a high-end speaker system INFINITY developed in the mid-1970s. It builds on technology from the Servo Static 1A and brings in passive radiator concepts and dispersion control. It is a floorstanding four-way design, with dedicated drivers for the low, mid, middle-high, and high ranges. The Walsh Tweeter is the unusual part. It radiates sound 360 degrees horizontally and fills the room with it. A user testimonial from 1977 confirms a strong reception at launch, with listeners praising its immediate musical impact.

Specifications

Model Rating Method	4-way, 4-speaker floor type
Units Used For low band	30 cm cone type
Units Used For Medium Range	10 cm Cone Type
Units Used For Middle and High Areas	2.5 cm Dome Type
Units Used For High Range	Special Type (Walsh Tweeter)
Frequency characteristic	28 Hz to 28 kHz ± 4 dB
Impedance	8 Ω
Allowable input Appropriate amplifier output	25W or more (RMS/ch)
Allowable input Maximum input	250W (RMS/ch)
Walsh-Tweeter diffusion Horizontal	360 degrees
Walsh-Tweeter diffusion Vertical	60 degrees
Crossover frequency	800 Hz, 4 kHz, 10 kHz
Level control	For Middle Area
External dimensions	Width 565 x Height 927 x Depth 432 mm
Weight	33.5 kg

Design

The INFINITY 2000 II uses a 30 cm cone woofer with a specially coated diaphragm for the low band, a 10 cm cone midrange, and a 2.5 cm dome unit for middle and high frequencies. The high range is handled by a Walsh Tweeter, which operates on a unique principle: a vertically oscillating metal cone—shaped like an "ice cream cone" with striated lines and coated in a gold thin film—radiates sound as a cylindrical wave. This design differs fundamentally from conventional cone, electrostatic, ribbon, and ion drivers. The crossover network employs a Butterworth filter to ensure phase coherence and accurate transient response. The enclosure features a replaceable top panel: one with black fabric for sound diffusion matching the grille, and another in hand-finished oil-treated walnut for aesthetic integration.

Context

At a time when most high-end speakers relied on conventional dome tweeters with limited dispersion, Infinity pushed

Market

The INFINITY 2000 II came with a five-year warranty on parts and labor. It was originally priced at ¥199,000 around 1976, which was a significant investment, aimed at serious audiophiles looking for advanced acoustic performance and innovative design.