I've found that a pair of Yurbuds has helped my PFII immensely. They bring out the depth of these earbuds, increasing the overall impact of the presentation, as well as depth of bass. Furthermore, they do not distort the sound. I tried the Yurbuds with my PK1 and PK3, and in both cases, although the sound was more pronounced as with the PFII, the soundstage was a bit distorted by them. My theory is that the PFII do not suffer from this because they are the same shape as the Yurbuds; it's like they were designed for each other. However, on the standard earbud design, it sort of 'funnels' the sound in a way that the earbud was not designed for, causing a sort of compression in the soundstage, while still offering the richer depth. Anyway, I tried Lorspeaker's trick a few days ago, and that definitely helped things; i particularly find the highs to be better articulated and clearer. I think the Yurbuds still offer some protection, so I figured I'd knock out the little plastic cross in the hole as well. This setup really brings out the potential of the PFII, and I far prefer them over my PK1 and pretty much any of my other headphones; I haven't used any of my other portable headphones since last year (except for running, which is what PK3 are for).
http://www.yurbuds.com/#
Edited by f4phantom2500 - 9/1/11 at 12:13pm