I don't think there's an exact definition. For I understand boomy as too much uncontrolled bass, but mostly a bit deeper. The kick of a drum is located more around 100-150Hz, while the body of a drum is lower. Personally I really dislike midbass humps, while I like an emphasis on low bass as long as its still controlled and well structured. The DT1350 does that quite well in my opinion, reaching low when called for, but not emphasizing any specific area.So "boomy sounds" are located in the sub bass, and in the midbass and upper bass frequencies are located the kick drums?
The HD25 does have a slight emphasis on midbass, but is leaner below that, so I'd not classify it as boomy. I think DJs like that one because its easy to hear the rhythm of the bass with that frequency response (it also emphasizes high hats).
All in all its always best to hear for yourself of course. Those two models might be a good start, and you can work from there.