I <■::
Table of Contents
Introduction • .•
Unpacking Instructions
Installation
ill.
A. Placing the Speakers ,
B. Connecting; the Speakers •
■;'^/;i;\/::Wire^;S'e^^^ i.--.- z
2! ^;Phâsihÿ/WÍпhg''.
'3/ ■'.'Fusing,'-- ■ ' •
C. Connécting the Equalizer; . i -•■ vï v. >:V
1, Using ihe Tap.e MohitprCircuil, . . ,. ''•■ ■■.••'; " ' . , •
2. -Osing Separa'té^Gbmpbhérits;-Connecting'Betwèeh^Jihè.T ,
; ' ;3.' ,‘Using:the;P.re^ ^
. 4. iUsingTour-Ci;^ . :
Connecting Other Equipment ; "
IV.
A. Tape Reççrâers ; --H
B. ■ Heabphopys;^ Conventional:.Speàké
V.
• A. So,urce:'and::Rb6m.Gorhp'pns^^^^^^
•:r
VII. Warranty
B] Adjusting the-Source and Rdprn Cornpdnsation Controls
: y C. .Speaker■placement : ....
. D. Room Acoustics
VI. Technical Information
A. Specifications ■'
B. Voltage Conversion
C. In Case of Difficulty
D. Care-and Maintenance . :• ,
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12
14
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17
19
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I. Introduction
Thank you for purchasing the BOSE 901 Series IV Olrect/Reflecting® speaker system. The listening enjoyment you will ex
perience Is the culmination of many years of research dedicated
to the art of bringing superb musical reproduction into the home,
The BOSE 901 Series IV. with its high proportion of reflected
sound, nine full-range drivers, and a newly-designed electronic ac
tive equalizer, is installed, connected, and operated differently
than conventional loudspeakers. The detailed installation and
placement instructions found in this manual are important.
PLEASE TAKE THE TIME TO READ THESE INSTRUCTIONS
CAREFULLY. VVith proper installation, you will be rewarded with
the unique listening pleasure provided by your 901 speakers.
II. Unpacking Instructions
The 901 Series IV speaker system Is packed in two cartons mark
ed “Part 1” and Part 2.“ The active equalizer is found in the car
ton filler material along with the “Part 1“ speaker. Unpack both
cartons carefully. Save the cartons and packing material for
possible use later. If either of the speakers has visible damage
when unpacked, do not place the damaged speaker(s) in opera
tion. Repack the speaker(s) in the original carton with the com
plete packing material and notify your dealer immediately.
III. Installation
Your 901 Series IV speaker system consists of three parts: two
speakers {marked “Pan 1 ” and “Part 2“) and an electronic Active
Equalizer packed in the “Part V* container. Installation consists
of three steps: 1)placing your speakers for best sound, 2) connec
ting the speaker to your amplifying equipment, and 3) connecting
the equalizer to your amplifying equipment.
If you place the speakers within the ranges suggested here, the
unique adjustments found on the 901 Series IV equalizer will allow
you to achieve optimum performance. (See SECTION V).
A. PLACING THE SPEAKERS
Unlike conventional speakers, the 901 Series IV functions with
the acoustics of your listening room, simulating the spatial
characteristics of the larger environments associated with a live
performance. This important advantage allows considerable
■freedom of placement and produces an unusually large “best
listening area." Outstanding performance can be obtained
under a wide variety of placement positions. (See Figure 2.)
The following guidelines in placing the speaker cabinets will
help you obtain the best performance. The basic idea is to pro
vide space to allow the sound to develop around the speaker
system.
1. The angled grille panels found on the enclosure are the
rear face of the 90i speaker (see Figure 1). Point this por
tion of the speaker toward the reflecting wall (the wall
behind the speaker). The point of the “V“ should be bet
ween 12’ and 24*’ from the reflecting wall. Best results will
be obtained with the speakers placed between 12" to 18"
from the reflecting wall.
2. Speakers should be placed at least 18" above the floor or
below the ceiling (see Figure 1). Distances closer to the
ceiling or floor restrict the reflected sound energy.
3. The speakers should be at least 18" from a side wall or
opening into an adjacent room. (Suggested distances are
3' to 5'.) Large objects (such as furniture) should be at least
24“ away from the side of the speaker.
4. Best results will be obtained with the speakers spaced
apart 6' to 10'; however, separation as small as 3' or as
great as 15' will give excellent results in most rooms.
If you have not decided where to place your speakers and
would like more information, SECTION V (LIVING WITH YOUR
BOSE 901 SPEAKERS) provides several additional suggestions
for speaker placement.
Installation
B. CONNECTING THE SPEAKERS
1. Wire Selection
If the wire used to connect the speakers to your power ampli
fier has too much resistance, audible coloration of the
sound and loss of power can result. The table below sum
marizes maximum wire lengths for 18-, 16-, and 14-gauge,
two-conductor, stranded copper wire for use with one or
two pairs of BOSE 901 loudspeakers.
TABLE 1
RECOMMENDED CONNECTION WIREt
.Wire Length
One Pair
of 901s
27 feet
Wire Length
Two Pairs
of 901s
13 feet
Type of Speaker
Hook-Up Wire
18-gauge zipcord
(or two-conductor wire)
i
42 feet
21 feet
1
67 feet
34 feet
16-gauge two-conductor
wire
14-gauge two-conductor
wire
In most instances, copper zip-cord, readily available at
most electrical and hardware stores, can be used for
speaker connection. This wire usually has a ribbed line(s)
along one side of the insulation so that each wire can be
identified for proper phasing of your speaker system.
tThe wire lengths snown m Table i were calculated on the bass oJ a rnaJtimum auditHe
colorat on ot ^0 5dB Following ihegudelmes provided, the most discerning listener
will be unable to detect any coloration introduced by the speaker wire Most listeners
will not notice any eHect isven if wire lengths are increasec by as much as 5054
2. Phaslng/Wiring
ft is important that the amplifier connections for both
901 speaker systems be identical (see Figure 3) so that
both speakers work together (in phase).
a. Start with the speaker marked "Part 1."
b. Place it on the left side of your room facing the
speaker system.
c. Locate the “ + " and terminals on the bottom of
the speaker.
d. Using the speaker wire (which is marked to distinguish
one conductor from the other), connect the "Part 1"
speaker terminal marked to the terminal marked
“com." "negative," or "minus" on the left channel
amplifier output. (When connecting the 901 Series IV
loudspeakers to your amplifier, if there is a choice of
impedances on the amplifier output, use the terminal
marked "8" or "8 ohms.” If two pairs of 901 Series IV
loudspeakers are being connected, the terminal marked
"4" or "4 ohms" on the receiver or amplifier should be
used.)tt
e. Connect the “-f" terminal on the left speaker to the
terminal marked "pos." "positive.” or “plus" on the left
channel output of the amplifier or receiver.
NOTE: Use only the terminals marked “ + " and
The terminal marked is intended for future electro
nic developments and should not be used with conven
tional amplifying equipment.
ttNote When operating your 90is m stereo, only one equalizer is required if addi*
tioriat pairs of 901$ are used, they can be purchased without the equalizer. These
speakers are sokJ as ' add-on'' pairs and can be connected as extensor speakers or
used in addition to the iirst pair of speakers
When connecting two pairs of 901 speakers to your equipmeni, v/ire the speakers m
parallel: most recently manufactured receivers or amplitiers wjI operate two pairs of
901$ wired n this manner. However, if your receiver or amplifier is not caceWe of
4-ohm ocerato.^ with two pairs of 90is. w^re the speakers in se.nes. Contact your
dealer if any further assistance is required
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