I'm playing a melee sneak build and would like to better understand how different melee weapons affect detection when used.

For example, how do the detection mechanics for a kill using a super sledge differ from a stealth combat knife? I've tried a variety of melee weapons and honestly haven't noticed much of a difference when performing OHKOs. IS there actually a difference? Do heavy/large weapons make more sound? What about blades vs blunt? I've read several threads on melee stealth, but haven't found any with solid answers on this topic. I'd love a link if there is one!

(I have sneak rank 4, which I assume negatives the movement penalty for heavy weapons in the same way it does for armor)