Carry a couple of speakers — it's a question of destination (7)
I believe the answer is:
whereto
'carry a couple of speakers it's a question of destination' is the definition.
I can't judge whether this defines the answer.
'carry a couple of speakers it's a question' is the wordplay.
I cannot really understand how this works, but
'of' could be 'o' and 'o' is found in the answer.
'question' could be 'where' (I've seen this before) and 'where' is found within the answer.
'it' could be 't' (abbreviation. e.g. in 'tis) and 't' is located in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for whereto that I've seen before include "Towards which place" , "To which (archaic)" .)