Watch the Drop 3, 4 Voicings: online guitar lesson by Brad Carlton from Guitar Lab: The Golden Arp
The final voicing of the drop 3, 4 add 9 chord is 3rd inversion. Only one voicing is produced with the middle two strings unused. Apply fingerpicking or hybrid picking and watch your intonation. Fretting hand fingering is discussed in the video demonstrating the merits of utilizing a grand barre for the 1st voice as opposed to a fingertip approach. This is a big sounding voicing because of the inverted power chord in the bottom two voices.