One of the benefits of in ear monitor of type headphones is that they offer better isolation, better sound and less spill other types of headphones (especially those evil white ones, the ones that are louder on the F###### outside than the inside).
In this Instructable I will document how I improved my Sennheiser IE4, the same techniques will also work for Sennheiser CX300's, the Sharp, Sony and Creative models that are all very similar to previously mentioned models.
Let me also bring your attention to some other Instructables in a similar vien
Step 1: Why Do This
The expanding foam tips offer improved sound quality and better isolation due to the improved seal and better coupling they offer, however if your ears are as Mingy as mine they need to be replaced quite often. These tips due to their expanding nature fit most sizes of ear perfectly.
The rubber tips come generally in three sizes and are a lot easier to clean. However finding a good fit can be difficult, I have also experienced that these tips loose some of their elasticity over time and as such the seal deteriorates.
In this Instructable I offer a middle way.