[jseth]

If that D-28 is a brand new one? Just keep playing it,a and play it hard... the thing needs to get broken it a bit. is all...

Certainly different strings would alter the tone slightly; I'm a phosphor bronze fan, myself, but no matter what strings you put on it, it's still going to be rosewood guitar and as such, will have those characteristics of rosewood back and sides w/ spruce top...

If you don't care about that "crisp ring" that fresh strings have, try a set of the MArtin Authentic phosphor bronze... after about 6-8 hours of play, they soften up and "dull up" quite bit... the longer you keep them on, the "softer" they become, without the jangly high end of many strings.

I prefer that "crispness" and like to hear my guitars ring out, so I use Elixir Nanoweb phosphor bronze strings; after about 2 hours of playing time, they "morph" into a tone that hangs in there for months at a time... works for me!