In this age, I wouldn't go w/ anything except wireless speakers. My W Hawk came with 2 external speakers that can be selected with or without the internal speakers. I'd be careful though getting too carried away with external speakers since loud music is probably one of the most common complaints about fellow campers.
When we first started using our TT we thought we wanted outdoor speakers as well. After camping in it a few times we realized that it would be better to get a portable speaker system. We use both our XM Radio and our phones (Pandora, Spotify) to listen to music, etc. We get much better reception outside and when we are sitting away from the TT (campfire, etc) we can move the speaker close and still hear our music without having to crank up any speakers that would have been attached to the TT thus bothering our neighbors..
We are "that family", you know.. the ones who stay up until midnight or later.. So we really try our hardest to be as quiet as we can.
Our Jayco Bungalow came with outdoor speakers mounted on metal siding. They work through the inside stereo system and work well. Almost too well. It is hard to get the volume so you can hear it plainly but not disturbing the neighbors.