Sunday, February 14, 2016

BOSE 151SE Environmental Speaker – Disassembling - test procedure – Audio system repair and service

Category : Audio System Repair and Service 

Contents of this article 

  • Disassembling procedure 
  • Test procedure 


1. Grille Removal
1.1 Remove the grille by pulling on the ends with your fingers, or pry carefully with a nonmetallic object.
Note: The grille is made entirely of metal. Do not try to remove the grille by pulling on the plastic (polypropylene) speaker enclosure.
2. Enclosure Dissassembly
2.1 To disassemble the enclosure, place the unit on a flat soft surface grille side down. Remove the 8 screws identified below.
Note: The unit is press-fit together. All parts of the unit must be in place prior to replacing the 8 screws.

2.2 With the unit face down, gently pull up on the rear enclosure. Be careful not to lift the unit too high, as the Twiddler® speakers are wired to the rear enclosure. Lay the rear enclosure on its side to expose the inside of the unit and the Twiddler speakers as seen below.

Note: There are no screws in the Twiddler® speakers, they are held in place by the press fit between the rear enclosure and the baffle.
3. Crossover PCB Removal
3.1 Perform Procedure 1.
3.2 Remove the 2 screws identified below that secure the crossover assembly.

3.3 Make a note of the wiring configuration. Lift out the crossover PCB and cut the wires as close to the terminals as possible.

4. Twiddler Removal
4.1 Perform procedure 1.
4.2 Make a note of the wiring configuration. Lift the Twiddler speakers out and cut the wires as close to the wire terminals as possible.

5. Twiddler Replacement
5.1 Set the center Twiddler speaker in place first, then the two outer Twiddler speakers. Take care to lower the outer Twiddler speakers straight down when setting them in place, this will ensure that the gasket seats in the correct location.
5.2 Wire the Twiddler speakers as shown below.

6. Enclosure Re-assembly
6.1 Re-install the Crossover PCB. Connect the PCB as shown in the wiring diagram and the schematic diagram.
6.2 With the baffle face down, lower the enclosure over the baffle. Dress the foamed wires toward the center of the loudspeaker enclosure.
Note: Ensure there are no wires visible through the speaker port once assembled.
6.3 Reinsert the 8 screws that secure the enclosure to the baffle assembly.
6.4 Perform the test procedures in this manual to ensure that there are no air leaks or wire buzzes before returning the speaker to the customer.
7. Grille Replacement
7.1 Align the grille to the speaker enclosure and push in lightly
1. Air Leak Test
1.1 Apply an 8Vrms,105Hz signal to the speaker input terminals.
1.2 Listen to the front of the speaker carefully for air leaks from around the cabinet seams, and Twiddler speakers. Turn the speaker over and listen for air leaks from the enclosure securing screws and drivers.
2. Sweep Test
2.1 Apply a 6Vrms Vrms, 10Hz signal to the speaker input terminals.
2.2 Sweep the signal generator from 10Hz to 3kHz and then back to 10Hz.
2.3 Listen carefully for buzzes, ticks, rattles or other noises. Replace the Twiddler speakers if they are found to be defective.
Note: To distinguish between normal suspension noise and rubs or ticks, slightly displace the cone of the twiddler with your fingers. If the noise can be made to go away or get worse, it is a rub or tick and the twiddler should be replaced. If the noise stays the same, it is normal suspension noise and the twiddler is okay. Suspension noise will not be heard with program material.