there are two basic mods: the tape mod and the foam mod. The first mod (and the simplest) decreases the bass response. All you have to do is take a small piece of tape and place it over the three holes on the back of the earbud. You can also do this with glue, it's obviously more permanent that way but it does look better. Try it with the tape first to see how you like it. The second mod decreases the treble. Not many people do this mod because they don't have a problem with the ex70's treble response, but I found my ex70's treble to be screetchy. On the end of that little tube that goes into your ear, there's a small piece of paper that sort of caps it. If you pull that little piece of paper off you'll find that the tube is hollow. Then you take a little piece of foam (I used foam from an old headphone pad) and stuff it into the tube. You can use as much or as little foam as you want, to either reduce or increase the treble as much as you want. I tend to do this a lot, I call it foam equalization . After reducing the treble and the bass, I think the ex70's sound much more balanced, and the midrange comes out a bit more. They become much more musical, and I use them all the time now whereas before I almost hated using them. Hope this helps...
