A lot depends on your listening preferences, which you have not described for us. If you just want to play background music, pick a pair of speakers and place them where you want. They will probably be too loud close to the source and not loud enough farther away.
I agree with Kal (as always), a dedicated space will give you the best option to hear music the best way e.g. optimized for the room. Pick your gear according to the size of the dedicated space.
Third option: why do you need to be limited to one rig? You can place two or more small systems in various parts of the barn space, the setup optimized for the "local" space. This is a no brainer if you will be using an audio streamer like Sonos or the Logitech systems. If you use active speakers you will not need anything other than the streaming devices and the speakers. More gear is a good thing, IMHO. Disclaimer - my wife does not agree.
I agree with Kal (as always), a dedicated space will give you the best option to hear music the best way e.g. optimized for the room. Pick your gear according to the size of the dedicated space.
Third option: why do you need to be limited to one rig? You can place two or more small systems in various parts of the barn space, the setup optimized for the "local" space. This is a no brainer if you will be using an audio streamer like Sonos or the Logitech systems. If you use active speakers you will not need anything other than the streaming devices and the speakers. More gear is a good thing, IMHO. Disclaimer - my wife does not agree.