This is a bit from left field. I am just about to finish yoga teacher certification. The studio where I might do some classes has a Sonos system, but I have trouble connecting to it with iPhone (I am not alone with that). I am thinking of getting my own portable solution and wonder about options. Here are my parameters.

Connection option from iPhone:
- mini jack to use a Dragonfly Red DAC
- USB cable
- BlueTooth

I use Flacbox as my iPhone music player, mostly FLAC, some MP3s.

Power:
- battery optional
- AC power ok, I have a strong 110V battery from my studio strobes I use for photography.

Sound:
well, that is of course the main thing here. I fully understand that it is not going to rival a proper high end system, but even with portables there are better and worse options sound-wise. And, I fully understand that the full benefits of FLAC files can not be appreciated on a portable speaker.

Set up should be quick (no more than 2 minutes on location). Should be reasonably shock resistant.

Output volume does not need to be high, music is rather background, as I need to be able to talk over it with un-amplified voice. Room size up to about 40x40 feet/12 x 12 m. I am looking for natural sound, not bass heavy. I have B&W CM6S2 as my home speakers (plus sub), and use Etymotics XR4s and Grado R2 as my headphones.

Price: try to keep it under $1K US

The most promising thing I have found so far is the Bowers & Wilkins Zeppelin, but seems to be no longer produced? New version coming? Anything else to consider? JBL (various options, not sure about details) and B&O Beoplay are popular.

What else should I look at?