Bowers & Wilkins 704 S2 User manual

The contents of this document and associated files contain confidential information that is propriety to B&W
Group Ltd., and are intended solely for the purpose of servicing the product. The information is intended for use
by service technicians familiar with electronic products. No part of the contents should be supplied or published
elsewhere.
Page 1 © B&W Group Ltd 2017
Hub Service Technical Manual
704 Series 2
Gloss Black San White Rosenut

The contents of this document and associated files contain confidential information that is propriety to B&W
Group Ltd., and are intended solely for the purpose of servicing the product. The information is intended for use
by service technicians familiar with electronic products. No part of the contents should be supplied or published
elsewhere.
Page 2 © B&W Group Ltd 2017
Date Revision By Details
21/05/2018 1JP Creaon
Revision History
Front Cover Page 1
Revision History Page 2
Contents Page 2
Introducon Page 3
Technical Sheet Page 4
Exploded Diagram & Parts List Page 5 - 6
HF/ MF Crossover Diagram & Parts List Page 7
LF Crossover Diagram & Parts List Page 8
1. Tool Kit Page 9
2. Cosmec Inspecon Page 10
3. Plinth Removal Page 11
4. Tweeter Removal Page 12 - 14
5. Mid Removal Page 15 - 18
6. Drawbar Adjustment Page 18 - 19
7. Bass Removal Page 20 - 21
8. Terminal Tray/ Port Removal Page 22 - 23
9. HF/ MF & LF Crossovers Page 24 - 27
10. Funconal Test Page 28 - 29
11. Cleaning Page 30
12. Spare Parts Page 31
13. Product Test List Page 32
14. Test Result Sheet Page 33 - 34
Contents

The contents of this document and associated files contain confidential information that is propriety to B&W
Group Ltd., and are intended solely for the purpose of servicing the product. The information is intended for use
by service technicians familiar with electronic products. No part of the contents should be supplied or published
elsewhere.
Page 3 © B&W Group Ltd 2017
Introducon
Please read this manual carefully before commencing servicing!
Only qualied and authorised technicians should aempt to service this product.
Anstac Precauons (ESD)
Electronic devices and components are extremely sensive to electrostacs
(ESD). Always observe ESD precauons when handling electronic modules or
PCBs. Never exchange boards with a dierent revision number, unless
authorised by B&W Whenever you see this warning,
always take electrostac
precauons.
Chemicals and Solvents (COSHH)
Solder’s, uxes and cleaning agents are used widely in the servicing of electronic
products. Such substances are hazardous to health; therefore always take
precauons to protect yourself and others when using any hazardous substance.
Protecve clothing and equipment if provided should be worn. If in doubt refer
to the COSHH.
Be aware whenever
you see this warning.
Electricity
Electricity is the most common hazard that will be confronted when building
and tesng product. Always take precauons when working on live
equipment or with any test equipment that uses electricity. Note: Do not
wear an ESD wrist strap when working on live electricity. Be aware whenever
you see this warning.
Personal Protecon Equipment (PPE)
PPE is equipment that will protect the user against health or safety at work. It
can include items such as safety helmets and hard hats, gloves, eye protecon,
high visibility clothing, safety footwear and safety harnesses.
Be aware whenever
you see this warning.

The contents of this document and associated files contain confidential information that is propriety to B&W
Group Ltd., and are intended solely for the purpose of servicing the product. The information is intended for use
by service technicians familiar with electronic products. No part of the contents should be supplied or published
elsewhere.
Page 4 © B&W Group Ltd 2017
704 S2 Series Technical Sheet
Technical features Decoupled Carbon Dome tweeter
Connuum cone FST midrange
Decoupled midrange
Aerofoil prole bass cones
Flowport™
Descripon 3-way vented-box system
Drive units 1x ø25mm (1 in) Decoupled Carbon Dome high-
frequency
1x ø130mm (5 in) Connuum cone FST midrange
2x ø130mm (5 in) Aerofoil prole bass
Frequency range -6dB at 43Hz and 33kHz
Frequency response 48Hz - 28kHz ±3dB
Sensivity 88dB spl (2.83Vrms, 1m)
Harmonic distoron 2nd and 3rd harmonics (90dB, 1m)
<1% 100Hz - 22kHz
<0.5% 300Hz - 20kHz
Nominal impedance 8Ω (minimum 3.1Ω)
Recommended amplier power 30W - 150W into 8Ω on unclipped programme
Dimensions Height: 925mm (36.4 in) cabinet only
959mm (37.8 in) including plinth
Width: 165mm (6.5 in) cabinet only
252mm (9.9 in) including plinth
Depth: 255mm (10in) cabinet only
277mm (10.9 in) inc. grille and terminals
298mm (11.7 in) inc
Net weight 18.5kg (41 lb)
Finishes Cabinet: Rosenut
Gloss Black
San White
Grille: Black
Grey (San White only)

The contents of this document and associated files contain confidential information that is propriety to B&W
Group Ltd., and are intended solely for the purpose of servicing the product. The information is intended for use
by service technicians familiar with electronic products. No part of the contents should be supplied or published
elsewhere.
Page 5 © B&W Group Ltd 2017
Exploded Diagram & Parts List

The contents of this document and associated files contain confidential information that is propriety to B&W
Group Ltd., and are intended solely for the purpose of servicing the product. The information is intended for use
by service technicians familiar with electronic products. No part of the contents should be supplied or published
elsewhere.
Page 6 © B&W Group Ltd 2017
Parts List
ITEM PART NAME DESCRIPTION
PART #
BLACK
PART #
WHITE
QTY
1NXM10000056703000 Gasket 5” Chassis PM/CM/68x S2 GG12742 GG12742 2
2NXM10000067381000 Scr M4x12 Cap Hd CR3 Black HH35904 HH35904 8
3NXM10000099337000 Bass Unit 5” 704 S2 LF26824 LF26824 2
4NXM10000056095000 Port Tube Inc Flare 50x25mm Abs Black PP17601 PP17601 1
5NXM10000106827000 T/Ring Assy LF 700 S2 5” Dark RR35211 RR35289 2
6NXM10000104602000 Midrange Fixing Assy 702/704 S2 ZZ34142 ZZ34142 1
7NXM10000064490000 Tweeter Gasket GG14184 GG14184 1
8NXM10000108617000 X-Over LF 704 S2 XX16950 XX16950 1
9NXM10000105282000 Grille Mesh 700 S2 HF (I/B) Black GG16012 GG16012 1
10 NXM10000065708000 Term Tray/ Port 50mm Nickel 6 Mntg Studs ZT26670 ZT26670 1
11 NXM10000099341000 Mid 5”” Dark Trim 704 S2 LF27170 LF27189 1
12 NXM10000067048000 Grille CM8 S1/2, 704 S2 Black ZG02899 N/A 1
13 NXM10000108581000 Decoupler MF 5” - Front—700 S2 MM14613 MM14613 3
14 NXM1000010682000 Trim Assy HF 700 S2 (Bae) Dark RR35440 RR35432 1
15 NXM10000067015000 CM8 S2 / 704 S2 Plinth Assy Black ZZ28665 ZZ28673 1
16 NXM10000108616000 X-Over HF/ MF 704 S2 XX16969 XX16969 1
17 NXM10000098329000 Tweeter Bae Mounted 700 S2 HF01511 HF01511 1
18 NXM10000058250000 Gasket Term Tray 1mm Polyethylene S/A GG06491 GG06491 1
19 NXM10000070716000 MF Centraliser Nut HH36463 HH36463 1

The contents of this document and associated files contain confidential information that is propriety to B&W
Group Ltd., and are intended solely for the purpose of servicing the product. The information is intended for use
by service technicians familiar with electronic products. No part of the contents should be supplied or published
elsewhere.
Page 7 © B&W Group Ltd 2017
HF/ MF Crossover Diagram & Parts List
ITEM DRAWING NUMBER DESCRIPTION PART # QTY
ASSY NXD10000108616 X-Over CM8 HF/ MF S3 XX16969 1
PCB NXD10000110813 PCB 3 Way—HF/ MF S3 CC72133 1
HAR NXD10000065997 CM8 S2 HF/ MF Harness Assembly ZX10146 1
C1 Cap5.6 M-Cap 450VDC EVO Silver Gold Oil CC64653 1
C2 Cap 47uF PP 250V Carli CC58164 1
C3 Cap 10.0 M-Cap 450VDC EVO Silver Gold Oil CC64661 1
C4 Cap 0.01uF TDK 630V RAD EPCOS 10mm Pitch CC87165 1
C5 Cap 0.01uF TDK 630V RAD EPCOS 10mm Pitch CC87165 1
C6 Cap 0.01uF TDK 630V RAD EPCOS 10mm Pitch CC87165 1
L1 Ind 0.75mH 1.2Wire 24 ID 50OD 33L Pacic ZL11428 1
L2 Ind0.7mH 1.2mm AC Bobbin Pacic ZL11215 1
R1 Res 1R5 1% Powertron RR34304 1
1White Cable Ties 530mm x 9.0mm CC14540 1
2Label CM8S3 HF/ MF Crossover LL14222 3
3Spacer. SRS8-8-01 HH31619 1
4Heat Sink Ali “”Type B”” - 50.4mm Long HH40363 4
5Termal Pad Q Pad II—102 (Bergquist) HH31039 1
6Heat Sink Clip 2004 800 Series X-Overs PP19695 1
7Adhesive Hot Melt 988A 11mm OD AA14494

The contents of this document and associated files contain confidential information that is propriety to B&W
Group Ltd., and are intended solely for the purpose of servicing the product. The information is intended for use
by service technicians familiar with electronic products. No part of the contents should be supplied or published
elsewhere.
Page 8 © B&W Group Ltd 2017
LF Crossover Diagram & Parts List
ITEM DRAWING NUMBER DESCRIPTION PART # QTY
ASSY NXD10000108617 X-Over CM8 LF S3 XX16950 1
PCB NXD10000108566 PCB 3 Way—LF—CMS3 CC72125 1
HAR NXD10000066262 CM8 S2 LF Harness Assembly ZX10197 1
C1 Cap 120uF 100V 5% Elec B04 CC57642 1
C2 Cap 0.01uF TDK 630V RAD EPCOS 10mm Pitch CC87165 1
L1 Ind 2.52mH 1.2mm P2535+P4507 x 2 Cose Pacic ZL11231 1
L2 Ind 1.0mH 1.2mm P2535+P4507 x 2 Cose Pacic ZL11193 1
R2 Res 0R5 1% Powertron RR34282 1
1Cable Tie 300mm 4TR—1194#5 CC60001 4
2Labwl CM8S3 LF Crossover LL14214 1
3Spacer, SRS8-8-01 HH31619 4
4Heat Sink Ali “”Type B”” - 50.4mm Long HH40363 1
5Thermal Pad Q Pad II—102 (Bergquist) HH31039 1
6Heat Sink Clip 2004 800 Series X-Overs PP19695 1
7Adhesive Hot Melt 988A 11mm OD AA14494

The contents of this document and associated files contain confidential information that is propriety to B&W
Group Ltd., and are intended solely for the purpose of servicing the product. The information is intended for use
by service technicians familiar with electronic products. No part of the contents should be supplied or published
elsewhere.
Page 9 © B&W Group Ltd 2017
1. Tool Kit
The tools listed in the below table are required to carry out the servicing of the 704 Series 2
Speakers.
1. HF/ MF Tool Kit 2017
2. Phillips Screwdriver
3. Allen Key 3.0mm

The contents of this document and associated files contain confidential information that is propriety to B&W
Group Ltd., and are intended solely for the purpose of servicing the product. The information is intended for use
by service technicians familiar with electronic products. No part of the contents should be supplied or published
elsewhere.
Page 10 © B&W Group Ltd 2017
2. Cosmec Inspecon
A Cosmec Inspecon is done visually and should be done before any work commences.
This is to ensure that there is no external damage to the 704 Series 2 Speaker.
The Cabinet (Including Speaker Terminals & Flowport) (1), Tweeter (2), Mid Driver (3),
Bass Driver (4) should be checked for damage during the inspecon. (Damage should be
noted in report)
1
2
3
4
4