I just got to thinking, maybe you would enjoy a fantastic pair of earbuds?! The
Moondrop Chanconne are some TOTL earbuds (and I can vouch for them honestly). Other than needing some quantity of bass EQed in (for anything other than classical), they have the some of best tuning I have ever heard (I wish I could find a pair of IEMs and headphones tuned like them).
Or maybe the
Yincrow RW2000 might suite you better?! They are a bit more neutral compared to the Chaconne, and have more bass quantity, but are also very detailed and revealing. Both have some of the best soundstage, and imaging out there to go with it. The RW3000 just came out and is supposed to improve on the 2000, but I can't vouch for that, not having heard them myself. The 2000 I also own, and can say they are my number 2 behind the Chaconne.
There are a ton of others out there ranging from dollars to hundreds of dollars, but I have only heard the likes of:
- Moondrop Chaconne
- Yincrow RW2000
- Rose Technics Maria II
- Smabat ST10S (150 Ohm)
- Smabat M2S Pro
- Dunu Alpha 1
They all pair really well with the DX300, but some (like the Rose Maria II) have a really high pinna gain, making them too hot for my sensitive ears in that area.
Anyhow if you aren't into earbuds, disregard this whole post as my ramblings.

And thank
@Whitigir for getting me back into this

of earbuds.