Bose 601 II DIRECT/REFLECTING Service Manual - Page 3

Browse online or download pdf Service Manual for Speaker System Bose 601 II DIRECT/REFLECTING. Bose 601 II DIRECT/REFLECTING 11 pages.

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TECHNICAL DESCRIPTION

SPATIAL CHARACTERISTICS

The Bose

601™ Series II system is a high performance floor-standing speaker designed to

achieve the highest level of spatial realism and spectral accuracy in a non-equalized Direct/

Reflecting

speaker system. The new 601 Series II speaker incorporates two new concepts in

speaker technology: The Free Space

array, which allows the drivers to radiate freely in any

direction, providing exceptionally realistic and natural-sounding energy distributing in almost

any listening room. The second new concept is the Sub-port Enclosure System, figure 1. Each

woofer has its own enclosure that has damping material and a sub-port. The sub-ports are

tuned to operate in the frequency range of 200-300Hz, providing principal sound radiation in

these frequencies through the sub-port rather than the cone. The sub-ports are coupled to the

main port of the speaker, and with the new extended range woofers, tweeters and crossover

network, the 601 II speaker takes maximum advantage of this new technology.

SPEAKER CONFIGURATION

WOOFER: Two new high-efficiency 8" woofers designed for the sub-port enclosure. Each

woofer has a long excursion voice coil and suspension, plus a 14 Oz. magnet, providing high

output capability. Uniform response of the woofer is over 2.5KHz with use of the Dual

Frequency™ crossover network. One woofer is directed forward while the second woofer is

directed upward, which helps create a balance of reflected and direct energy in the listening

room.

TWEETER: Four 3" wide-range high sensitivity tweeters per enclosure provide flat power

radiation beyond 15KHz. The response extends down to 1.5KHz for use with the Dual Fre-

quency crossover network. Two tweeters in each speaker enclosure are directed outward so

that most of the sound energy is reflected off the back and side walls. One tweeter is posi-

tioned so that the sound energy is directed towards the center of the room and the final

tweeter is positioned to reflect sound off the back wall between the speakers and into the

room, providing a strong center stereo image by filling the "hole in the middle".

DUAL FREQUENCY CROSSOVER NETWORK: Located in the top woofer cup, the crossover

network consists of two capacitors, two resistors, and two tweeter protection lamps. The Dual

Frequency crossover network is designed to offer performance advantages by deliberately

operating both the woofers and tweeters simultaneously over a significant part of the frequency

range. We have designed the crossover network to have separate transition frequencies for

the woofers and tweeters. By using separate frequencies, an overlap in response of almost

one octave is achieved, providing smoother frequency response in the crossover region.

Careful design of all components in the crossover network matches woofer and tweeter re-

sponse, eliminating phase cancellation and assuring accurate frequency and transient re-

sponse.

Enclosure: A sub-port enclosure system for maximum efficiency, minimum cone motion and

placement versatility. Cabinet is constructed of walnut grain vinyl laminated to particle board.

Note: The early version of the 601 II speaker has three input terminals. Later versions had

two input terminals. Refer to the schematics and crossover part lists in this manual for differ-

ences.