Watch the Drop 2, 3 Voicings: online guitar lesson by Brad Carlton from Guitar Lab: The Golden Arp
The drop 2, 3 Add 9 chord in 1st inversion can fool your ears because 9 (2) is the lowest voice. Remember that this occurs anytime the 3rd voice has been dropped. Use care in the lower registers and be sure to listen against a low root outside of your guitar (or tap the bass note as demonstrated in the video). Obviously if E is the key, you can use the 6th string open as a bass note. These two forms involve a little bit of contortion so take it slow and don't strain your 2nd finger (it has to arch excessively).