2
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.
