I am not really good at describing but here goes:
Bass quantity texture:
Bass is very controlled and tight with much more texture. It doesn't have as much bass as the R2A and it is much more cohesive with the rest of the sound. The Duke has less quantity than the R2A but better quality bass. Bass lines are very easy to identify but the bass isn't emphasized. Its just that the Duke is so clear and transparent, that all the components are really easy to identify (much more so than the R2A)
Treble Presence/Peaks
- With the Duke I am using foam tips
http://penonaudio.com/HAVI-Foam-Eartips; Comply works as well
- Duke was bright at first with some sibilance. Have used quite a bit since getting the Duke and it has mellowed nicely. It is crisp clear and transparent. To the point that I can tell the difference between Dacs (Fiio E17 is noticeably less detailed than the SMSL M2 when using the Duke)
- Duke is brutally honest, so you need good source gear
Mids
- R2A is noticeably mid recessed in comparison to the Duke.
- Duke is awesome with wood wind instruments, guitar, vocals etc
- Duke + Femal vocals = fantastic combination
Others:
- Amazing instrument separation and layering - can hear everything in a song
- Most realistic presentation of natural instruments I have ever heard, you gotta hear drum hits to see what I mean. So natural and effortless
- Vocal master: No matter the track, male or female, it does great with vocal, if the track is vocal, it can isolate it and bring it to the front where as with R2A the vocals sound muffled in comparison and not as easy to hear
-The duke has a more realistic soundstage compared to the R2A
Overall Duke is technically more proficient than the R2A but R2A is more fun and forgiving, whereas the Duke is more clear, transparent and neutral with good balance. With a good dac, you are going to get a dead accurate presentation of the song.
Lemme know if you have any specific questions.