EarFun - UBOOM Raver

I did a deep dive on this a while back and settled on an Earfün Uboom, which was recommended for two reasons  1. It has firmware available that was tuned by some famous audiophile guy 2. You can find coupons for it that give you like 20 bucks off so it's like 50-60 bucks. It has aux in as well as BT. Good battery life. You just need to be comfortable with the idea of changing the firmware to the specific recommended version. I use mine all the time. It can get quite loud but it is also absolutely dreamy at low volume. Sometimes I rest it on my forehead and it feels like I am wearing fancy invisible headphones. Also, you should read the user manual. It has two modes, one high latency mode for multi-device bluetooth and a low latency mode for single device bluetooth / aux. You switch by double pressing the BT button.  Oh and it's waterproof I guess but I'm not going to test it. I like mine quite a lot. https://www.reddit.com/r/Bluetooth_Speakers/comments/1fle9of/the_earfun_uboom_l_is_insanely_good/