Finding that out for you specifically, and I'll update you here! Thanks for the appreciative words, the feelings are mutual.
@Sound Eq , Audionewbi is right! A wide U-shaped frequency response, very cohesive due to using a single dynamic driver, the bass and treble have more energy and excitement due to raised dB but the IE 80 S doesn't fall into the trap of some U or V shaped headphones where the mids put vocalists in the background. The IE 80 was praised for surprisingly good imaging, with a soundstage of distinguishable width and depth, and the IE 80 S is also great in this regard. Feed it with Binaural tracks, on-location recordings, or video games with headphone surround processing and the IE 80 S does them justice! Around the office, we prefer different ear tips among us; about equal votes between which tips have the best comfort, but the Complys come out a head by a bit especially for those with more unique ear canal shapes, but the two different silicone tips are also popular for their durability and how fast they are to insert and clean.
The IE 80 S has the same connector to the cable, but the new cables have a strain relief added where we saw more wear on the cable in the IE 80. Another tip to prolong the longevity of IEM cables: try to pull them out by the IEM housing, not the cable. However, as in all things portable, of course things get snagged and accidents happen, so the strain reliefs should help that. On an aesthetic note, the right strain relief is also colored a crimson red, recalling the "right is red" mantra and signifying that the IE 80 S is indeed part of our high-end lineup.
Detailed here:
https://www.head-fi.org/threads/meet-the-sennheiser-ie-80-s.859251/#post-13694731
The short version is we tweaked the existing IE 80 design based on community feedback without changing what people loved about the original, so that you can have longer listening sessions and longer ownership. Think of the IE 80 S as a blend of audiophile and professional gear, like an IEM version of our also classic HD 25.
Thanks everyone for your comments! We've also shared this thread's feedback with our project managers, and our Audiophile Lead Axel Grell. We should have more discussion and answers soon.