Kimu, Are talking about the large metal scew on the back of the speaker? If so, this is not supposed to be locked down fully tight.
I asked B&W about this on my N803's, here is their reply:
"The correct tension for the FST unit is set in the factory and should not need any adjustment, the easiest way to explain it is to take a coin and try turning it, it should feel 'finger tight' If this is to loose the FST midrange unit may fall out, if it too tight you will squash the isolation material inside."
I asked B&W about this on my N803's, here is their reply:
"The correct tension for the FST unit is set in the factory and should not need any adjustment, the easiest way to explain it is to take a coin and try turning it, it should feel 'finger tight' If this is to loose the FST midrange unit may fall out, if it too tight you will squash the isolation material inside."