(Always trying to be objective in my assessments.)
Looking for new outdoor speaker in Aug 2017 and laid about 2v. research online where I went through written tests and especially youtube clips, eg: https://www.youtube.com/user/clavinetjunkie/search?query=flip+4?&ab_channel=clavinetjunkie. Then bought the JBL Flip 4 and JBL Charge 3 and compared them which landed in that Flip 4 is probably (so far, Aug. 2017) the best waterproof speaker in its size and price range. Ended up with the return of Charge 3 and bought another Flip 4 and now these two stereo speakers are connected via the 3.5 mm jack to the computer as well as portable outdoor and indoor speakers.
Total sum: Still a gun purchase July 2019!
* Ultra-compact speakers with clear and dynamic, powerful sound.
* Waterproof, feels very solid, good tactile buttons.
* Flexible thanks to the 3.5 mm jack, that you can connect up to 100 wirelessly and the app that allows you to choose between party mode or stereo via bluetooth.
* Very durable - had them on the sandy beach and the pier all summer.
* Canon price now 700: - buy two!
Some little things I annoy me at:
* The sound quality via Bluetooth is, as always, noticeably worse. AptX had probably helped to bypass this problem.
* Via bluetooth, the sound is 0.5 sec so if you eg. playing games use 3.5 mm layer-free cable instead. 2 Flip shines as best via cable in stereo. NOTE: if you have 2 Flip 4 then connect 3.5 mm _mono_ plugs to each speaker otherwise it will not be true stereo.
* Unfortunately you cannot get genuine stereo sound via Bluetooth with 2 Flip 4 (app missing) from Windows.
* A small, small nail for hard treble (however, may be ripped off: https://www.youtube.com/watch?v=JnjIFXsIWAY&t)
* You can select the next song via the speaker buttons, but not the previous song :(
* The Android app takes a long time to find the speakers or even fails sometimes.
* Had been nice if it was possible to upload other USB gadgets from the speaker, as on the JBL Charge.