The affect of weather on bookshelf speakers outside depends on the weather. Seriously, if you live in a very humid environment (SE or coastal areas) I could see issues. Cabinet veneers coming off, rusting fastener, etc. If you have a set of bookcase speakers and you don't mind if they get trashed, go for it. For wire, I'm using in wall speaker wire - Carol brand? Once the deck and deck cover (not 100% weatherproof) are installed, I'll paint what ever outdoor speaker I get and the wire to blend in. I spoke to the folks at Partexpress. They thought the Carol in wall speaker wire would be fine outside for little section that is actually exposed. I figured a coat of paint would help protect the wire covering. My speaker wire run through the walls to get to the outside. Hence the reason for the in wall rating.