Tingy, I just got back to Freespace and the HLP a few months ago after being away for 17 years. I'm loving playing FS1 and 2 again, especially loving playing FS1 Port with the FS2 engine. Also, get Knossos. Seriously, get it because it makes installing and playing most Freespace mods a snap once you get it properly installed and configured. It keeps track of which mods you have and which you have yet to get, a very helpful feat.
Sound issues I know nothing about, though.