Watch the Drop 2, 4 Voicings online guitar lesson by Brad Carlton from Guitar Lab: The Golden Arp
The 2nd inversion drop 2, 4 voicing of the add 9 chord is a very open, useful form. It is voiced from low to high as follows: 3 1 5 2. Register considerations are not as critical as the 1st inversion forms as the 3 is stronger in the bass than the 9(2). The two fingerings for this voicing require a bit of stretching, but the results are well worth the effort.