Bose 601 Series II & III

A floor-standing direct/reflecting loudspeaker system designed to deliver 901-like sound at a lower cost

Overview

The Bose 601 is a floor-standing loudspeaker system available as both the Series II and Series III. Designed to bring the acoustic performance of the flagship 901 system into a more accessible form, the 601 uses a unique multi-driver layout to create a balanced, room-filling sound field. Unlike conventional speakers, the 601 relies on wall interaction and strategic driver placement to achieve its direct/reflecting effect, making positioning a key part of its design.

Specifications

Model Rating Method	2-way, 6-speaker, direct / reflecting system, floor type
Low Band Units	20 cm cone x2
High Range Units	7.5 cm cone x4
Crossover frequency	1.5 kHz ~ 2.5 kHz (Dual Frequency System)
Impedance	8 Ω
External dimensions	14 by 29 1/2 Inches (front), 13 Inches deep
Weight	16.4kg
Original price	$890 per pair

Design

The Bose 601 uses a "Direct/Reflecting" design with five of six drivers mounted in the upper enclosure. Two 20 cm woofers handle low frequencies, each in an independent sub-enclosure connected via a sub-port that controls standing wave effects and guides back pressure to the main chamber, where lower frequencies exit through a top-mounted port. Four 7.5 cm cone tweeters are arranged in a 360° unobstructed layout, angled to radiate sound in all directions. Two of the four tweeters increase outward energy at higher frequencies via a crossover network with bypass capacitor. The crossover uses a dual-frequency system where both woofer and tweeter operate between 1.5 kHz and 2.5 kHz, reducing point source effects. The tweeters use special pulp with high internal loss and Young's modulus, while voice coils employ a space rocket-surface-treated polymer for heat resistance. A control switch allows toggling between asymmetric and symmetrical tweeter output depending on room placement. The speaker is designed to be placed near the back wall, with three drivers radiating upward to maintain balance when near furniture.

Context

The Bose 601 was developed as a more affordable alternative to the 901 system, leveraging similar acoustic principles like the free space array method and indirect/direct sound balance derived from live performance modeling. It reflects Bose’s focus on room-filling sound through reflective acoustics rather than forward-focused directivity.