Connectivity Issues With Apple Products
Sennheiser headphones are designed to have the best audio and build quality possible. If the headphones have sound in only one ear or the sound in general is not as expected then it needs to be determine where the issue lies - with the headphones or with the audio source.
Sennheiser products that have a "i" in the model (ie: PMX 686i) are designed for connectivity for Apple products and incorporate a microphone and control into the cable. These products have been tested for compatibility and do work with most Apple products however sometimes an update on a product like an iPhone, iPod, etc will cause functionality issues and a reboot of the device (ie: turning it completely off and then back on) is required to get functionality back. NOTE: These models are designed for connectivity to Apple products and the integrated microphone/control will not work on non-Apple products.
Here are some things to try;
- Check and make sure that there is no debris (ie: no dust or lint) in the headphone jack of the device that may be inhibiting connectivity and causing sound issues and also make sure that the headphone connecting jack is clean.
- Ensure that the connecting jack is clean. If sweat evaporates on the plug the salts and grime may prevent proper contact from occurring. The connecting jacks can be cleaned using a basic alcohol wipe.
- Try the headphones on a different audio source to check that it is not the original audio source (or a setting on the audio source) that is creating the issue. If the headphones are connected to an alternate audio source and the issue is not there then that indicates that the headphones are fine and the original audio source is the issue. NOTE: Many modern audio devices have an audio limit pre-set at the factory and these limits need to be changed to get the full audio signal out of the device and to the headphones.