I think some examples might be in order..
(eadgbe = X,X,X,X,X,X)
all A7 chords (or fragments of..) (A7 = A C# E G = root 3rd 5th b7th)
small voicing (7th and 3rd)
7th in the bass:
X,10,11,XXX
XXX,5,6,XX
XXXX,0,2,X
(identical pitches on different string pairs..)
3rd in the bass:
XXXX,2,3
XXX,6,8X
XX,11,12,XX
(identical pitches as before..)
voicings with more notes:
3rd in the bass:
XX,11,12,10,12 (3rd, 7th, Root, 5th)*
XX,11,12,10,9 (3rd, 7th, R, 3rd)*
X,4,5,6,5,X (3, 7, 3, 5)
XX,11,12,14,15 (3, 7, 3, 7)
XX,11,9,8,9 (3, 5, 7, 3)
XX,11,9,8,12 (3, 5, 7, 5)
X,4,2,0,2,0 (3, 5, 7, 3, 5)
9,X,11,9,8,X (3, 3, 5, 7)
And many others...
5th in the bass:
X,7,5,6,XX (5, 7, 3)
X,7,X,6,8,X (5, 3, 7)
XX,14,12,14,15 (5, 7, 3, 7)
XX,14,12,14,12 (5, 7, 3, 5)
12,X,11,9,8 (5, 3, 5, 7)*
and many others...
7th in the bass:
XX,5,6,5,X (7, 3, 5)
XX,5,6,5,3 (7,3,5,7)
X,10,11,12,X,12 (7,3,7,5)*
X,10,11,9,8,X (7,3,5,7)
X,10,X,9,8,9 (7,5,7,3)*
I've deliberately included some not so great sounding voicings to illustrate not all A7 chords are created equal.
For the most part I avoided the stock voicings you find in your average '1001guitar chords!' book.
* particularly interesting ones