What are the exact places of articulation of Korean coronal consonants, e.g. ㄴ, ㄷ, ㄸ, ㄹ, ㅅ, ㅆ, ㅌ?
The passive articulators are dental, alveolar, or postalveolar, and the active articulators are apical or laminal. What are the exact combinations for the consonants above?
In my pronunciation, all stops (ㄴ, ㄷ, ㄸ, ㅌ) are lamino-postalveolar. What's interesting is how I discriminate ㅅ and ㅆ. My ㅅ is apico-alveolar [s̺], and my ㅆ is lamino-dental [θ̻], if not as non-sibilant as English [θ]. For ㄹ, it is apico-postalveolar (or in other words, apical retroflex), for both central version ([ɽ̺]) and lateral version ([ɭ̺]).
I doubt every Korean has the same articulations, but was there a study on this?