A set form of home entertainment (3,3)
I believe the answer is:
the box
This clue could be a double definition.
'a set form' is the first definition.
Although both the answer and definition are singular nouns, I can't see how they can define each other.
'home entertainment' is the second definition.
The definition and answer can be both man-made objects as well as being singular nouns.
Perhaps there's an association between them I don't understand?
'of' is the link.
Can you help me to learn more?
(Another definition for the box that I've seen is " TV (sl.)".)