I have one of these, Bose ® SoundLink Bluetooth Speaker III - Silver: Amazon.co.uk: Electronics.
I am very pleased with it, I connect it to my phone, my laptop, my wife's tablet. It has plenty of volume, I can hear backing tracks when playing my sax, the base comes through well, and I can carry it round the house easily. I suggest you find a retailer who will let you connect your phone and try it.
It will connect via a 3.5 mm jack as well as bluetooth.. I stream the radio, soundcloud and Cafe Sax recordings to it.