The spade connection is not primarily from fitting tight against the post, but rather from the clamping force of the nut squeezing down on it. If you think about contact area, there is only a very thin edge against the post, but the flat area on the top/bottom of the spade are a large area.
spade connector around post or 1 prong thru hole?
I just bought a pair of 989's and speaker cables with spade ends. The 989 manual does not say to straddle the posts or put one prong through the hole in the posts (the hole through the post, not the cylindrical hole inside the post). I searched the internet and found some speaker manuals say around/straddle the post (even though they do have a hole for bare wire connections), some say one prong through the post. Any recommendations out there, either 989 owners or in general? My spade does straddle the post fairly well, but not as "snuggly" as I would have thought. Also, same question for connection to the amp, which method gives the best connection/sound? Thanks.