The problem was gradual: the cable of the right atrium has started messing around but it was periodic.
A few weeks later, more sound on the right: I plug another smartphone (android), the sound works on both atria, I put it back on the iPhone 4, the headset works well.
Then three months later, the headset does not work anymore: I send it in for repair and the time I recovered, I changed my smartphone.
I finally get at the end of a month, and even topo: it works well at first and then after a certain point, one of the two channels are cut. I think this comes from bad micro-welds and finally I decided not to buy Sennheiser.
