I think i'd like to see the ".com" in the lower right corner.
Maybe make the over arching semi circle just a fraction thinner. (just a tiny bit)
Maybe the top part of the mirrored "S" just a little thinner?
Also, maybe lighten up the grey (just a tad) in the logo only... not in "Defacto Sound" & make the ".com" in the lower right the same lighter shade as the logo.
I would LOVE to see any other ideas you may have. I like your style!
I changed the logo as you wanted. Little thinner whole "s", "d" (if i make only the top of the "s" thinner, it doesn't look nice but of course i can add it too, if you want to see it), and the upper part of the headphone.