How do I get my bluetooth speakers to work correctly?

I just bought a new bluetooth speaker today (Rockbox by Urban Beatz), and I can’t get it to work right. I was able to connect it with both my phone and my computer and it worked for a bit, but then when I tried to reconnect after shutting the speakers off, all it does is make a strange garbled noise. Kind of like muted random blips. It shows that my music is playing on my computer/phone, but the speakers aren’t playing anything.

I would consult the manual about this issue, but unfortunately, I left it in the box at my mom’s house. I’ve also tried googling the problem a hundred different ways with no luck. Thanks for any and all help!

(my computer is an HP envy m6 with windows 8.1 and I have a iphone 4s with iOS7, if any of that info helps)