I've bought these headphones mainly for Gym use, since I sweat like there is no tomorrow, I needed something more than a sweat resistant, and these headphones looked like they would endure the gym abuse.
Unfortunately after just a couple of weeks of use, the left ear phone went mute during a workout session.
I've wash it and dry it like recommended in the manual...but...
In the next gym use, I've noticed that the sound from the left ear phone was a bit strange.
Back home and in silence I retested the phones and found that in the left ear volume was lower than on the right and there was no bass???
Very strange, so I open the ear phone and guess what... there was water inside the diaphragm, yes, there was water around the moving coil driver and the magnet, thus the headphones are RUINED, since there is no way to dry that place, unless you destroy the diaphragm.
A deeper analysis shows that the back of the magnet is in no way protected from water so water can go inside and obstruct the moving coil.
This design error is not tolerate at this price level and since it is stated that the PMX 680 are: "Sweat- and water-resistant ideal for sports".
I'm forced to give them a complete negative review due to misleading information.