I had a set of Shinko 705's on a KTM640 Enduro, they worked great on the street and very good off road as long as it was dry. The only downside is they are only available in 1 size for 19" wheels. 110/80-19 in a radial or bias ply tire. MC superstore has the bias on sale for 49.95 right now. You could go with the classic Dunlop K70's too, they work great on the street and very good off road if its dry. If you plan to do any mud, sand or loose dirt riding a more aggressive dual sport type would do better. But some can sing very loud once worn a bit, I have some Michelin dot knobbies on a rxv 450 above 40 mph they sound like a monster truck coming down the road. People standing along the roadside snap their head around to see as I go by, expecting to see Bigfoot or Gravedigger...LOL .
My exhaust is stock & quiet.