Just noticed that 1964 are achieving a very substantial large-bore=>small-bore ratio with the tubing on their ADEL module:
Or perhaps they are using a moulded plastic manifold, but I can't quite see a definite junction between the two, if that is the case.
Or maybe the ADEL module sits in an unusually deep solid acrylic portion of the shell, with that void (at the junction of ADEL module and it's dedicated soundtube) being moulded or drilled-out of the solid acrylic.
I recall Starkey (now M-Fidelity) using what appear to be custom-moulded sound tubes, on the SA-43, which is a nice way of maintaining consistency across numerous customers' pairs of CIEMs. It's always struck me as strange that more CIEM vendors don't use this approach, unless BAs have a less consistent batch frequency response than one would hope. Perhaps we will see more of this approach, with the increasing momentum of 3D printing technology (in which case, it might be done as an
integral feature of the printed CIEM shell itself)
...whilst I'm on the topic of peculiarities in CIEM construction, I've never noticed any CIEM maker (professional
or DIY) doing what Sony did with their soundtubes, here:
http://www.head-fi.org/t/739725/sony-announces-the-just-ear-brand-of-custom-iems/60#post_10993232
Anyone else have examples of such peculiarities not frequently seen in mainstream CIEMs?
I do appreciate that this is a DIY CIEM thread, but some cross-germination of ideas can be a positive thing, and I don't see why commercial makers should have all the fun.
In that spirit, here's some more food-for-thought, to get the old grey cells whirring:
http://www.head-fi.org/t/753632/introducing-the-worlds-first-lear-patented-nss-natural-stereo-sound-earphone-technology