why a 12-string

A Acoustic Guitar Forum friend asked, "why a 12-string and not a 6-string?". I think the following is correct, although to tell the truth, I don't know if I can put into words why I play a 12-string.
"As for 12 vs. 6 sound differences, a 12 has two distinct sounds when finger picking.
The octave courses (strings 3, 4, 5, 6) are struck with the thumb and strings 1, 2, and 3 are usually picked
with i, m, or a. The 3rd string can be hit with thumb or fingers, and will sound very different depending which is used. When the 3rd string is struck with the thumb it tends to have both the high and low course resonate, and when fingers are used only the lower string sounds strongly. Pieces like Bach's Cm prelude for Lute tend to sound good because the 2 voices sound like different instruments.



The octave course strings are complex enough so that single string runs can be slow and long, more than a 6 string.

There also seems to be more collateral noise in a 12-string - the 'rumble' is really just string rattling on the frets. Because of this, I find it hard to make the music as clear and defined as a lot of 6 stringers can. An electric pickup helps the signal to noise ratio, but I would rather have an acoustic answer. And I actually like the incidental noise when I'm playing.

Even though I've been playing a 12-string for over 30 years, some of these things I've just learned, and I hope there will be more things to pick up in the next year.

Oh, and the 12 is really, really hard to record. I've been working on it for 3 years. The 12-String Cycle CD was better than the album before, but the Mastering Engineer gave me some suggestions for the next one, such as changing to omni mics in a Jeklin Array or A-B spaced. 12-String cycle was recorded with a pair of cardioid mics. I've changed to omnis in a Jecklin array and the new setup comes closer to what my playing sounds like in person. The bass seems fuller and more 'grand', not boomy."

Update:
For someone else's take on the 12-string difference, Gray Rollins has an interesting article, Comparing 6 String And 12 String Guitars