I don't think you're using the definition of "extension" properly honestly, in terms of sheer treble extension UE900=W4[wide bore tips]>ER4>SE535>GR10. Only the UE900 and W4 can reach 20k, tested via freq sweep and confirmed by FR graphs. I actually wish I had both to do a sine-wave comparison as to see which can reach 24k [yes I can hear that high].
Sounds like a poor fit on those SE535s, I think if I remember correctly, the SE535s 10k region makes it sound aggressive and forward when the insertion depth isn't right.
If the ER4 sounded aggressive on the treble, bad fit as well....it's smoother than GR10 and W4. ER4's subbass is horrid yes, midbass is fine.
This is my last post on this because I don't think you can hear past 16-17K and don't wish to argue. But just to go on record,,,,,
- IMHO ER4 is the easest fitting universal on the market. A straight thin plug with a tri-flange that you push in until it stops.....perfect fit for everyone everytime. It fits or it doesn't, there is nothing in between and this is what Mead was aiming for.
- The W4 is 3 to 4 times smoother, in fact waaay to smooth where it has no shimmer and no crispness. Ety is the exact opposite where it is just plain harsh and siblant especially at higher volumes and this is even with the charcoal foam tips. The reason your charts don't say that is because it is a BA single driver trying to do the job of what 3 drivers require and the result is a complete mess.
- GR10 treble is best of the best. The old SE530 has better treble extension than UE900. Perhaps I got a bad pair? That would be 3 out of 3 rejects I bought?
- Please tell me the ER4 extends deeper than the JH13 and JH16 so I can save $1,000.