I agree with bigwig. For my part I looked for other tips and found a website that proposes changes (see the forum). I tried the Boucons foam (as used by Shure) and that is pretty and comfortable. I was looking for a solution for a monitor and found InEar plugs for swimmers, Speedo proposes. But those I have just adapted Migros - Switzerland - and cost € 3! After tinkering should be: I took a nail I heated and I punched the caps. I have shortcuts to the base and that's it. For my part I now decreases the bass. I am very happy with the sound now. With original caps I could not do anything. I have pictures of the result for those who might be interested.