So, I couldn't resist opening them up:
...and in there I found the same driver as the UR22i, which, after previous experiments, sounds good. It does the same as the engine of the UR23i.
Here is a photo of the UR22i:
Personally, I like the UR22i's look, but, honestly the UR23i is a nicer set, ergonomically, and as a package.
Moving on, the driver is basically a "ring-ported" driver, like the Shure SRH1840, but without the acoustic paper filter...