Which ears these earphones to fit? And the sound could be so brilliant.

I had not expected when earphones from Sennheiser.
The tested here Sennheiser MX 686G sport earphones could be so beautiful.
In an almost too elaborate packaging, the earphones come. Included is a case with velcro, which is really convenient.
Visually appealing, the earphones are really well made. Everything makes a stable impression and give the user the impression that would be well suited for this sporty lightweight activities.

Now I tried the earphones in my, in my opinion, set to "Standard" ears. "Set" From press was, then rotate, then fumble ..... then give up.
Love Sennheiser thank to test for the chance one of their products. Unfortunately, they had to explain to me once hand which ears these earphones were developed.
Now I have now given the earphones 5 friends and acquaintances. None of these five people got this in the ears. For all they fell out after the slightest movement.
Therefore, not useful.

And the sound, assuming you can find is the exact point of the angle as the listener sitting needs, simply stunning.
Heights, depths and midtones are actually perfect for this design. Well-balanced and crystal clear. Unfortunately, however, only at a certain angle and wearing this I could stop only test in which I held my listeners with both hands on his ears.

A brilliant sound is not available unfortunately for me because apparently my ears are not standardized.
In this case I can not give as 2 star, unfortunately.
For the high price a potential buyer can also expect that the earphones fit without problems in his ears.