I've been using a Dropped D tuning on my Alvarez 12 string for years (get at least a .56 on the bass E and try an Ernie Ball .24 plain for the octive). Use a Keyser Dropped D Capo (about $15 'merican) on your selected fret and use a regular Keyser 12 string capo two frets lower to catch the "dropped" bass string. I call it "Dropped D in Any Key" and it works great. The Dropped D Capo has a rounded cutout where the bass string runs through it, and was originally intended for 6 strings. However I used a Dremel tool (small drill) to grind the cut-out larger for the double course strings, and now citterns want to have my 12 string's children. Try this configuration playing Dm positions in an Em song and you'll never go back.