Please help. I have a set of Bowers&Wilkins DM640i that I have replaced the woofers in and as of recently I have been getting an annoying crackling/popping noise out of one of the four 8” bass drivers. Sounds like a loose connection, but is not and only happens at around 100Hz. The measured resistance of the driver is 6.7ohms.I checked all connections on speakers in and out of the cabinet. The 8” driver had the same problem out of cabinet. Seems like voice coil may be hitting something. I don’t know? Is there a fix, like possibly heating driver with heat gun to center coil?
Please Help, speaker crackle at low volume.
sansuibutch
Super Member
I've had the issue with a couple drivers. One the glue was coming apart at the spider. The other one someone must have dropped the cabinet and the weight of the magnet pulled it out of allignment. the glue coming apart on the spider was more difficult to diagnose because when looking at it everything looked fine till I put my finger down in there and was easily able to separate the spider from the cone.
That’s sounds like a good start. I will look closer at the spider glue. Thanks
I looked At spider and found that it was intact. The replacement driver looks like it may have had the coil professionally repaired at some point though. Could it have been a faulty repair?
sansuibutch
Super Member
Anything is possible. I would set your tone generator to 100 hertz and get the speaker to make the noise. Then push on the cone in certain spots to see of you can make the noise better or worse. If so I would remove the dust cap and see how far out of alignment it is. The driver might need to be rebuilt or realigned.
