The HiFi BCD X10 earphones arrived in the mail today.
It turns out that the splitter is more compact that it appeared in the photos on eBay - so that's a good thing.
After switching to the larger silicone tips, I'm getting a good seal in my ears, without having to insert them uncomfortably deep.
Due to the length and shape of these earphones, they're the only ones in my collection that pretty much have to be worn with the cable down, in order to place them for best sound.
I've had them connected to my iBasso PB2 (dual OPA1622 op-amps), streaming New Orleans Jazz band "Tuba Skinny" videos (thanks to
@Wyville for posting a video in the "IEM/Ear Bud Lounge" thread) from my Roku4 and PC.
Due to having a forward Midrange, it seemed like they may be a bit Bass-shy, but I went to
https://www.audiocheck.net/soundtests_headphones.php and verified that they have Bass that's sensed at 10Hz, and audible beginning at 20Hz.
While on that webpage, I listened to Left, Right, Center, & Twisted - to check for mis-wiring, and determined that the drivers are in-phase, but the wires to Tip and Ring1 are swapped.
Aside from the issue of cable noise (which would usually be isolated better if I could wear the cable over the ear), and the fact that they're labeled and wired backwards (L <-> R), these X10 really do have a clear, detailed sound.