Depends on the size and tuning of the speaker. Headphone speakers are much larger and usually have far better tuning than most earbuds, but then again lots of headphones much like earbuds sound like shit.

It's interesting to see the downvotes though despite what I am saying is literally the truth when it comes to earbuds and IEMs. They use one speaker for the entire range of sound in each ear. Nothing I said is incorrect.