RDB+ 2v1 Impressions:
Physically the housings are pretty large, huge in fact, but remain comfortable to wear. I had a hard time getting the best seal with the supplied silicone tips but the supplied foams worked great.
The supplied cable is an upgrade cable called the mono silver crystal cable, if I'm not mistaken. It has pretty good ergonomics. It's decently flexible and really hugs the ear. It does tend to hold a little too much of the shape in which it was stored but ultimately isn't a big deal due to its flexibility.
The 2v1 has a sensitivity of 32 ohms and 100db. It contains an 8mm dynamic and a twfk. The shell is vented with a pinhole sized vent near the cable sockets. It's very easy to miss. Additionally the cable sockets are recessed and the nozzles are dual bore, Aesthetically the silver carbon fibre faceplate, black shell and silver cable look pretty nice.
Upon first listen I though the 2v1 sounded very lean, albeit fast, and I wondered where the dynamic bass would come into play. After a few hours of listening and discovering best for my ears, I started to hear dynamic goodness. Overall I do find the signature to be leaner than the 1+2 and TG334 that I own. Frequency response seems pretty linear from bass through mids and with a moderate treble lift, giving the overall color that of an analytical touch.
I find the 2v1 sounds better with more power. I'm not really sure if this is due to current needs or just sounds better from a cleaner source. Of all my amps, the Rhapsodio Shozy pxm1 supplied for the USA tour sounds the best with the 2v1. Perhaps it was voiced with the RDB iem line in mind. It gives it a little more space and treble is smoothed. Overall the match with the Shozy is just more pleasing to my ears.
The 2v1 almost has delicate feel to the notes. I don't mean soft but somehow rather light and fragile. It sounds very good at lower to moderate volumes. At higher volumes I pick up some sibilance and the treble / upper mid emphasis can be a bit much for me. At lower volumes drums have a nice and fast snap and kicks have a lower deep bass emphasis. The tight lower bass, delicate note, Shozy pxm1 amp and lower volumes make for an overall enjoyable listening experience.