Tweeter adjustment?

[PhantomD]

Hi all,

I recently repaired a faulty speaker in our hall that was causing less than satisfactory sound reproduction in our system.

I singled out the centre mid-hi range tweeter as the source of our problems, and pulled it out of the speaker cabinet to inspect it. After studying it for a minute, I found a slightly loose screw on the back of it, tightened it as much as possible and put the tweeter back into the cabinet. It then didn't work to a dry solder joint, which I repaired the next day with an iron.

After fixing the dry joint, the tweeter resumed normal operation.

My question is, does anybody know the real purpose of this screw? It would loosen only so far, and then not come out, and it caused the horn to come loose inside when fully loose (=the distortion we were hearing). However the horn did not come out.

One of the other sound guys took it upon themselves to have a look at it, and they lost one of the retaining screws, so I went and got four nice new ones - a very professional job, in my opinion.

Thanks in advance,
Cheers
PhantomD