If it is 20' or less it is not to bad, you can get strut in 20' lengths.
I would go with 'double' strut which is almost 4" deep.
If you want to have a slick look, order it without holes and with snap on cover. Strut can be the raceway and you could chase nipple boxes on the wide sides of the strut where you need them.
The speaker cable could be zip tied to the outside of the strut.
Strut when used as a raceway is still allowed to be used as support.
Take a look at a B-Line or Uni-strut catalog for some ideas.
Over 20' and it gets a bit tougher.
