Loudspeaker wife left out for rock? (6)
I believe the answer is:
teeter
'for rock?' is the definition.
(I've seen this before)
'loudspeaker wife left out' is the wordplay.
'loudspeaker' becomes 'tweeter' (tweeter is a kind of loudspeaker).
'wife' becomes 'w'.
'left out' is a deletion indicator.
'tweeter' with 'w' taken away is 'TEETER'.
(Other definitions for teeter that I've seen before include "waver" , "Rock unsteadily on feet" , "Vacillate" , "Move with little assurance" , "Wobble as though about to fall" .)