Bose-4.2-Series-II-Service-Manual 电路图 维修手册.pdf

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1、BOSE Better sound through research 4.2 SERIES II DIRECT/REFLECTING SPEAKER SYSTEM SPECIFICATIONS Transducers: 1-8(20 cm) woofer 2-3(7.6 cm) tweeters Nominal Impedance: 8Ohms IEC Power Rating: Min: 10 Watts Per Channel Max: 75 Watts Per Channel 01992 Bose Corporation Cabinet: Black or wood-grained ve

2、neer Speaker Dimensions: 10.5H x 17W x 9.25 0 (27 H x 43 W x 23.5 D cm) Shipping Weight 33 lbs. (15 kg) Per Pair Service Manual RadioFans.CN 收音机爱 好者资料库 PROPRIETARY INFORMATION This document contains proprietary information of BOSE Corporation which is being furnished only for the purpose of servicin

3、g 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. BOSE 4.2 SERIES II TECHNICAL DESCRIPTION The BOSE 4.2 Series II System is an economical way to enjoy the legendary spatial realism of a Direct/Re

4、flecting system. This system creates a natural balance of reflected and direct sound that conventional speaker designs cant match. The result is lifelike spaciousness that approaches the realism of a live performance. Even sound distribution is also aided by Stereo Everywhere performance which enabl

5、es the listener to sit or stand anywhere and still hear the same volume and blend of musical instruments. This achievement is also aided by three high performance drivers in each cabinet: one 8 woofer and two 3 tweeters. The tweeters are arranged in a Stereo Targeting Array. This array directs high-

6、frequency sound in a defined pattern and complements the woofer in providing balanced stereo throughout the listening area. The 4.2 system employs the BOSE Dual Frequency TM crossover network. The crossover provides a smooth transition from low to high frequencies by sending sound to all the drivers

7、 over nearly a full octave. The result is a clear definition of each instrument and voice. Additionally, the system incorporates slot-port technology which reduces port noise and produces cleaner, more natural bass. The sum of all these unique features makes the 4.2 Series II speaker capable of repr

8、oducing the wide dynamic range demanded by todays advanced recordings without strain or loss of clarity. TEST PROCEDURES NOTE: Before performing any tests.remove the grille. Refer to the Grille Assembly Removal procedure. 1. Woofer Rub and Tick Test A. Connect a sine wave oscillator to a power ampli

9、fier. Adjust the frequency of the oscillator to 10 Hz and the amplifier output to 8 Vrms. Connect the amplifier output to the input terminals of the 4.2-11 speaker (see Figure 1 ). No extraneous noises such as rubbing, scraping or ticking should be heard. 1 RadioFans.CN 收音机爱 好者资料库 Audio Slgnal Gener

10、ator 0 Test Connections 4.2 II Speaker Power Amplifier Input Output Speaker FIGURE 1 NOTE: To distinguish between normal suspension noise and rubs or ticks, displace the cone on the woofer slightly with your fingers. If the noise can be made to go away or get worse, it is a rub or a tick and the woo

11、fer should be replaced. If the noise stays the same, it is normal suspension noise and the woofer is fine. Suspension noises will not be heard with program material. 2. Woofer Sweep Test A. Sweep the oscillator from 10 Hz to 3 kHz using the 8 Vrms signal. There should not be any loud extraneous soun

12、ds. If there are any loud buzzes or distortion, replace the woofer. NOTE: There should not be any buzzes or rattles from within the speaker cabinet. Redress any wire or component that buzzes. 3. Tweeter Sweep Test A. Reduce the amplifier output to 4.0 Vrms and continue sweeping from 3 kHz to 15 kHz.

13、 If one of the tweeters is buzzing or distorting, replace it. 4. Air Leak Test A. Using the 8 Vrms signal, set the oscillator frequency to 45 Hz. For at least 5 seconds, listen for air leaks around the woofer.terminal cup and tweeter mounting brackets. If there is a whooshing noise around the woofer

14、, re-position the woofer gasket behind the woofer to make an airtight seal. If there are any similar noises around either of the tweeter mounting brackets or the terminal cup, make sure that these items are securely fastened to the speaker assembly. 2 RadioFans.CN 收音机爱 好者资料库 Schematic Diagram Cl Rl

15、RTl YELLOW RED TWEETER (LOWER) IN WOOFER TWEETER (UPPER) GREEN :-.JBLACK FIGURE 2 5. Woofer Phase Test NOTE: Supply voltage should only be momentarily applied to the speaker input terminals to avoid possible damage to the speaker. A. Set a DC power supply to 8 volts. To ensure that the woofer is con

16、nected in phase, connect the positive lead of the supply to the positive(+) speaker input terminal and the nega- tive lead to the negative(-) input terminal. The woofer should move outwards with the appli- cation of the supply voltage. This ensures that the woofer and speaker input terminal are wire

17、d in phase. See the schematic in Figure 2. 6. Tweeter Phase Test Remove 4 screws and lift the woofer carefully away from the speaker cabinet in order to access the terminal cup. Check the wiring on the terminal cup and on both sets of tweeter terminals against the schematic shown in Figure 2. This e

18、nsures that the tweeters are wired in phase. GRILLE ASSEMBL V REMOVAL A. The grille assembly is held in place by 6 grille fasteners. To remove, CAREFULLY pull the grille away from the speaker (it should lift away easily). 3 REPAIR PROCEDURES 1. Replacing the Woofer A. Remove the 4 screws holding the

19、 woofer in place. (Refer to Figure 3 for an exploded view of the speaker assembly). Lift the woofer out and cut the wires connected to the woofer terminals as close to the terminals as possible. Strip the wires and connect to the replacement woofer. Make sure that the yellow wire is connected to the

20、 positive(+) terminal and the green wire is connected to the negative(-) terminal of the woofer. Remount the woofer to the cabinet using the 4 screws. Repeat the woofer test procedure. 2. Replacing the Tweeters NOTE: The positive(+) terminal of each tweeter is marked with a red dot. A. Upper Tweeter

21、 (1). The upper tweeter is mounted in a round mounting bracket. Refer to Figure 3. Remove the 3 screws which hold the bracket to the speaker assembly. Remove 1 screw (on the back of the bracket) which secures the tweeter to the bracket. Lift the tweeter away from the bracket and cut the wires connec

22、ted to the tweeter as close to the tweeter terminals as possible. Strip the wires and connect to the replacement tweeter. Make sure that the grey wire is connected to the positive +) terminal and the black wire is connected to the negative (-) terminal. Remount the tweeter in the mounting bracket by

23、 securing the tweeter with 1 screw. Secure the round mounting bracket to the speaker assembly with 3 screws. Repeat the tweeter test procedure. 8. Lower Tweeter (1). Remove 1 screw which secures the tweeter to the mounting bracket. Cut the wires connected to the tweeter as close to the tweeter termi

24、nals as possible. Strip the wires and connect to the replacement tweeter. Make sure that the red wire is connected to the positive(+) terminal and the grey wire is connected to the negative-) terminal. Secure the tweeter to the mounting bracket with 1 screw. Repeat the tweeter test procedure. REMOUN

25、TING THE GRILLE A. There is only one way to remount the grille assembly refer to Figure 3). The round end of the grille assembly should be furthest from the tweeters. Align the grille feet with the 6 grille fasteners. Press in lightly until the grille feet are engaged by the grille fasteners. The gr

26、ille assembly should be flush with the front and side of the cabinet. Make sure that the nameplate is oriented as shown in Figure 3. 4 Main Assembly Part Drawing VIEW A-A *= SEE CROSSOVER PARTS LIST FIGURE 3 5 Carton Parts Drawing FIGURE 4 6 4.2 Series II Parts List (Figure 3) Item Description Part

27、Number Qty. See Note Number Per Speaker Assv. 1 Grille Assembly-Dark Brown 148101-1 1 Grille Assembly-Black 148101-3 1 2 Nameplate-Clear/Black Bkgnd. 132545-01 1 Nameplate-Gold/Brown Bkgnd. 132545-04 1 3 Woofer -8 or 120713 1 Woofer-8 135372 1 4 Screw-HIRS,8-1 0 x3/4,PAN,XRC/SQ 137527-12 10 5 Woofer

28、 Gasket 120715 1 6 Grille Fastener 117995 6 7 Tweeter-Black,3 130714 2 8 Tweeter Mounting Bracket 128501 1 9 Screw-Machine,8-32x1/2,HEXW,HEX 121441-08 2 10 Tweeter Mounting Bracket-And. 148103 1 11 Terminal Cup Connector 120711 1 12 Screw-6-1 0 x1/2,PAN,XRC/SQ 138897-08 4 7 Crossover Parts List (Fig

29、ure 3) Symbol or Description Part Number Qty. See Note Item Per Number Speaker Assv. C1 Capacitor-Film,5%,50V,3.4F 106825 1 1 R1 Resistor-WW, 10%,5W,7.5Q 125605-7R5 1 1 C1 Capacitor-Film,5%,50V ,3.7F 107055 1 1 R1 Resistor-WW, 10%,5W,6.2Q 125605-6R2 1 1 C1 Capacitor-Film,5%,50V,3.0F 104130 1 1 R1 Re

30、sistor-WW, 10%,SW,9.1 n 125605-9R1 1 1 C1 Capacitor-Film,5%,50V,2.4F 104131 1 1 R1 Resistor-WW, 10%,5W, 13.0Q 125605-130 1 1 RT1 Overload Protection Lamp 141989 1 A Foam Tape 118223 NIA B Foil Tape 103597 NIA 2 C Glass Wool 103075 NIA 2 D Connector,Terminal,Wirewrap 118008 3 E Screw-TAPP,8x3/8,HEXW,

31、SLOT 103802-06 3 NOTES 1. C1 and R1 must be used in the combinations shown above in order to achieve the proper frequency response of the loudspeakers. 2. This part is not normally stocked as a service part. 8 4.2 Series II Parts List (Figure 4) Item Description Part Number Qty. See Note Number Per

32、Carton 1 Owners Manual 148335 1 2 Polybag (Literature Kit) 103351 1 3 Warranty Card 129287 1 4 Envelope 123001 1 5 All Products Brochure 141478 1 6 Warranty Service List 122766 1 7 Express Music Catalog 145891 1 8 Packing,EPS 129931 2 9 Polybag (Speaker) 106595 2 10 Carton 148097 N/A 9 SPECIFICATIONS AND FEATURES SUBJECT TO CHANGE WITHOUT NOTICE BO.SE Better sound through research. 8/92: REV.0 Bose Corporation The Mountain Framingham, Massachusetts USA 01701 P/N 149357 FOR TECHNICAL ASSISTANCE PARTS ORDERING, CALL 800-367-4008