If you get a portable speaker I would get the monster clarity HD. I've had it for a while and love it. It can be used with Bluetooth or cable. It's is the best compact speaker out by a long shot. The sound that comes from it is great. If you wish to get one go on eBay because I got mine for $60 and they go for $120.
The EQ app I posted improves all system audio not just files being played through player... I am able to drive down highway with windows down and still hear GPS clearly over road noise when without it I can barely hear the commands under same situation.