Regarding tips
With the caveat in mind that our ear anatomies are each quite unique, I wanted to share a few of my own observations tip-rolling with the FD5.
Wide bore tips
As shared in my initial impressions, I found the Symbio W, Symbio Peels, Azla Sedna, and Acoustune AET07 to highlight the upper-midrange/lower-treble emphasis and produce a decidedly splashy and inarticulate upper-treble. With the exception of the Acoustune AET07, the Symbios and Azla Sedna also tended to push back the lower-mids, resulting in a rather lean midrange and a dissonance between the upper and lower mids, exhibiting a kind of 'hollowness'.
SpinFit CP145
These are my favourite tips with the FD5.
They offer the smoothest and most refined sound
by far, taming the upper-mid and treble emphasis, and producing a wonderfully articulate and refined upper-treble. Technicalities are also the best of the tips by a fair margin, to my ears.
The graph below was taken from the Dunu Zen thread, and created by
@tgx78. Keeping in mind, of course, that the Zen is a different IEM altogether, I think the changes to FR depicted in the graph still provide a helpful indication of the relative effects of the tips measured:
Other possible suitable tips
- Spiral Dot. I haven't tried these on the FD5, but based on past experience, they tend to have the consistent effect of smoothing the treble regions and pushing the midrange forward. At the same time, they tend to attenuate the mid-bass, and can result in a somewhat diffuse imaging (which I find to be true of most wide bores with most IEMs).
- Acoustune AET08. These are my favourite tips for reducing treble emphasis and increasing low-end energy and overall tonal density, whilst resulting in the least compromise to overall technicalities. Compared to the AET07 or the SpinFit, though, they will lower the overall sense of air and openness.
- Final E. A lot of people seem to like these tips, and I can understand why. They generally produce a smoother, darker, warmer, and bassier sound. However, I personally find that they also tend to narrow the soundstage by a fair amount, and produce a stuffier sound overall, with noticeably poorer separation. As always, though, YMMV.