Got a new pair of paradigm studio 60's and i found that a cap on one of the speaker's posts is removed, exposing the metal jack underneath. Don't know why the cap is off, i just unboxed it, could be due to faulty transportation. The rest of the speaker is okay, the metal jack that got exposed after the cap is off appears safe. The cap itself doesn't appear to be physically damaged, it is just removed from the post. How do i put the cap back on, i tried rotating it clockwise and anti clockwise but it isn't working? And second question, i have built my speaker wire using banana plugs, the banana plug seemingly fits right into the exposed metal jack, but would it be safe to use the banana plug without the cap on?