A:AnswerI don't think it'd be loud enough for player walk ups, but for warm up music I think it would. It doesn't sound tiny by any means. I use it in the outdoor area at my gym and it definitely overpowers any and everyone else's music.
A:AnswerI've used the pulse2 and flip at the pool and used the charge 2 at the gym. I would suggest more than 1 for a pool party. With the JBL app, you can pair multiple speakers together.