Where to capo for Db minor
Put the capo at fret 4 and play Db minor using Bbb minor shapes. That is the easiest of the eight positions ranked below, and it is what most players reach for. Against playing Db minor open, it drops the mean difficulty of the key's seven chords from 4.4 to 3.4 and gains 9 ringing open strings.
You want Db. Capo 4 and play in Bbb.
All eight positions, ranked
Each row transposes Db minor down by that many frets to find the shapes your hand would actually make, then scores the best voicing of all seven chords — fewer fingers, less stretch, closer to the nut, fewer muted strings. Lower is easier. Standard tuning (E2 A2 D3 G3 B3 E4).
What you are playing
The seven chords of Db minor are Dbm, Ebdim, Fb, Gbm, Abm, Bbb, Cb — the ones the ranking above is scored against. Their diagrams are on the Db minor key page.