Bose 301 II Series User manual

1
SPECIFICATIONS
Driver Complement: One 8" long excursion woofer
Two 3" high sensitivity tweeters
Nominal Impedance: 8Ω
Dual Frequency™ Crossover: Woofer Transition 2.5kHz
Tweeter Transition 1.5kHz
Amplifier Power Requirements: 10 watts minimum
75 watts maximum
Cabinet: Walnut grain vinyl veneer
Dimensions: 10 1/2" H x 17" W x 9 1/2" D (27 x 43 x 24) cm
Weight: 18 1/2 lbs. (7.1 kg)
Shipping Weight: 40 lbs (18.18 kg)
PROPRIETARY INFORMATION
THIS DOCUMENT CONTAINS PROPRIETARY INFORMATION OF
BOSE®CORPORATION WHICH IS BEING FURNISHED ONLY FOR
THE PURPOSE OF SERVICING THE IDENTIFIED BOSE PRODUCT
BY AN AUTHORIZED BOSE SERVICE CENTER OR OWNER OF THE
BOSE PRODUCT, AND SHALL NOT BE REPRODUCED OR USED
FOR ANY OTHER PURPOSE.
Contents
Specifications................................................................................................................................... 1
Disassembly/Assembly Procedures .............................................................................................. 2
Test Procedures ............................................................................................................................... 3
Main Assembly Part List.................................................................................................................. 4
Figure 1. Exploded View .................................................................................................................. 4
Crossover Part List .......................................................................................................................... 5
Figure 2. Later Version Schematic Diagram .................................................................................... 5
Figure 3. Early Version Schematic Diagram .................................................................................... 5
Packaging Part List.......................................................................................................................... 5

2
DISASSEMBLY/ASSEMBLY PROCEDURES
Note: Numbers in parenthesis refer to call
outs in figure 1.
1. Front and Side Grille Removal
1.1 Grasp the grille (4) (3) by an edge and
pull it off.
2. Front and Side Grille Replacement
2.1 Line up the grille mounting feet with the
grille attachments (10) on the cabinet and
press the grille onto the cabinet.
3. Woofer Removal / Crossover Access
3.1 Perform procedure 1 first.
3.2 Remove the four screws (12) that
secure the woofer (1) to the cabinet.
3.3 Lift the woofer out of the cabinet and
cut the wires as close as possible to the
woofer terminals.
3.4 The crossover components are located
on the back wall of the cabinet.
4. Woofer Replacement
4.1 Attach the wires to the replacement
woofer (1). See the schematic diagram on
page 5 for the wiring configuration.
4.2 Replace the four screws (12) that
secure the woofer to the cabinet.
5. Tweeter Removal
5.1 Perform procedure 1 first.
5.2 Remove the screw (7) that secures the
tweeter to the tweeter mounting bracket (6).
5.3 Cut the wires as close as possible to
the tweeter terminals.
6. Tweeter Replacement
6.1 Attach the wires to the replacement
tweeter. Refer to the schematic diagram on
page 5 for the wiring configuration.
6.2 Replace the screw (7) that secures the
tweeter to the tweeter mounting bracket (6).
7. Terminal Cup Removal
7.1 Remove the four screws (15) that
secure the terminal cup (16) to the cabinet.
7.2 Cut the wires as close as possible to
the terminal cup.
8. Terminal Cup Replacement
8.1 Attach the wires to the replacement
terminal cup (16). Refer to the schematic
diagram on page 5 for the wiring configura-
tion.
8.2 Replace the four screws (15) that
secure the terminal cup to the cabinet.
9. Vertical Trim Strip Removal
9.1 Grasp an edge of the vertical trim strip
(9) an pull it off.
10. Vertical Trim Strip Replacement
10.1 Line up the vertical trim strip (9) with
the holes in the cabinet and press it into
place.

3
TEST PROCEDURES
1. Phase Test
1.1 Momentarily apply 8 ±1Vdc to the
speaker input terminals. Observe polarity
when connecting the dc power supply. The
woofer should move outward.
1.2 Momentarily apply the positive side of
an 8 ±1Vdc power supply to the red wire
that is attached to the tweeter. Connect the
negative side of the power supply to the
speaker's negative input terminal. The
tweeters should move outward.
2. Air Leak Test
2.1 Apply an 8Vrms, 45Hz signal to the
speaker input terminal.
2.2 Listen for air leaks around the woofer,
tweeter mounting brackets and the terminal
cup.
3. Rub and Tick Test
3.1 Apply an 8Vrms, 10Hz signal to the
speaker input terminals.
3.2 No extraneous noise such as rubbing,
scraping or ticking should be heard.
Note: To distinguish between normal
suspension noise and rubs or ticks, dis-
place the cone of the woofer slightly with
your fingers. If the noise can be made to go
away or get worse, it's a rub or tick and the
woofer should be replaced. If the noise
stays the same, it's normal suspension
noise and it will not be heard with program
material.
4. Power Sweep Test
4.1 Apply an 8Vrms, 10Hz signal to the
speaker input terminals.
4.2 Sweep the speaker from 10Hz to
3kHz.
4.3 Lower the applied voltage to 4Vrms
and continue to sweep the speaker to
5kHz.
4.4 Listen for any buzzes, rattles or other
extraneous noises from the speaker.
Replace any woofer or tweeter that fails
this test. Tighten any screws or redress any
wires that buzz.

MAIN ASSEMBLY PART LIST
Item
Number Description Part Number
1 Woofer 135372
2 Tweeter 130714 or 124618
3 Grille, Side, Tan
Grille, Side, Black
Grille, Side, White
Grille, Side, Green
Grille, Side, Blue
Grille, Side, Red
Grille, Side, Silver
120705-2
120705-3
120705-4
120705-5
120705-6
120705-7
120705-8
4 Grille, Front, Dark Brown
Grille, Front, Black
Grille, Front, White
Grille, Front, Green
Grille, Front, Blue
Grille, Front, Red
Grille, Front, Silver
120704-1
120704-3
120704-4
120704-5
120704-6
120704-7
120704-8
5 Screw, Bracket Mount, Hex Wash 108877
6 Tweeter Mounting Bracket 128501
7 Screw, Tweeter Mount, Mach, Hex
Wash 121441-08
8 Port 118752-0
9 Vertical Trim Strip 120707
10 Rubber Grille Attachment 117995
11 Trim Ring, Woofer 120709
12 Screw, Wood, #8 x 20 mm L 129027-12
13 Woofer Gasket 120715
14 Grille Mounting Foot 120706
15 Screw , SH Met, #6-20 x 5/8 103122-10
16 Terminal 120711
Figure 1. Exploded View
4
**
** Use Tweeter part number 124618 as an alternate for 130714. 10/06/00

5
CROSSOVER PART LIST
Description Part Number Note
3.4uf, 50V 106825 Match
7.5Ω119094-7R5 Match
3.7uf, 50V 107055 Boost
6.2Ω119094-6R2 Boost
3uf, 50V 104130 Cut
9.1Ω119094-9R1 Cut
2.4uf, 50V 104131 D Cut
13Ω119094-130 D Cut
RT1, Lamp 117805
+
_
YL
GN
WOOFER
C1 R1
RT1
UPPER
TWEETER
LOWER
TWEETER
GY
BK
++
+
_
_
_
RD
Figure 2. Later Version Schematic Diagram
Figure 3. Early Version Schematic Diagram
PACKAGING PART LIST
Description Part Number Qty
Owner's Guide 120749 1
Carton 142253 1
Filler 129931 2
Bag 106595 1
Note: 1.5A, 250V fuse kit, part number 108938-4
+
_
YL
GN
WOOFER
C1 R1
UPPER
TWEETER
LOWER
TWEETER
GY
BK
++
+
_
_
_
RD

©1996 Bose Corporation Service Manual
Part Number 122115
301®Series II Direct/Reflecting®
Loudspeaker
®
®

BOSE CORPORATION
THE MOUNTAIN
FRAMINGHAM, MASSACHUSETTS USA 01701
®
SPECIFICATIONS AND FEATURES SUBJECT TO CHANGE WITHOUT NOTICE
P/N 122115 10/96: REV. 02 FOR TECHNICALASSISTANCE OR PART ORDERS, CALL 1-800-367-4008
®