For 14.8mm driver I only used metal shell (blue one on image below), PK, Docomo and this one for "sleeping buds" (I will post the image when I finish the cable).Have you tried putting the 14.8mm PK2 speakers in earbuds like Qian39 or Faaeal Z-sound? I wonder if they are compatible. I really like the form factor of those but the sound could be easily improved with better drivers.
Also, have you tried the 6-hole wooden shells from nsc store? I'd get one if I know for sure they snap on 15.4mm speakers.
Yes ghxamp store has been selling those for a long time, jietu just recently added it. At ghxamp you can find reviews and graphs, I think this is very different from the 64ohm titanium, it's more like a bright midcentric speaker.
About old titanium 32ohm: I also heard that it was bright mid-centric and skipped that offer.
As for the wooden shell, I always pay attention to the following:
The first type with concave arc back can be seen on the models: NiceHCK EBX, Toneking models, Yinman 600om, etc.
EBX uses a 14.8mm driver but because of this shape seems like 15.4mm in the ear. Personally, I avoid this shape because I do not have good sealing.
The second "angled" shape uses Moondrop and also can be seen on Yinman 150ohm and some DIY models. This form is ok.
The third with a concave arc s my favorite shape for the reason that it has good ergonomics and is comfortable.
I will explain more about the design and ergonomics of different types of shells that I own when I have free time.
I recently tried a little experiment with this shell. The stock shell is too shallow and does not have good air circulation. On the plus side, the 15mm driver fits very well
and it's light-weight. So I try to drill hole on the backside and the shell split from heat into two parts. I replaced back part with a custom made wooden part.
I added a small hole at the back and mmcx socket.
Wood is not good quality but it served well for this experiment. The harder the tree the better.
The soundstage on these is wide and deep and it's quite noticeable. The sound is warm and resonance is produce an interesting effect.
For mid-centric drivers is a good choice, for bass dominant will be overwhelming.