Ok I contacted saberfonts.com and they said none of their fonts work with the obsidian soundboard. Yet I went ahead and bout one and it seems to work fine in the obsidian v4 launcher from my MAC. Are you sure you need to convert them to lsu files?
I'm quite sure they mean that none of the fonts work "perfectly" with Obsidian. They'll load, so long as they're in 48000hz and uncompressed, but they skip a little bit. Iunno.
No, you won't need to convert them from .wavs unless you're using Obsidian v3 in your saber. But a lot of them will need to be converted to 48000hz