A couple of things you can do to improve the 801M beyond the North Creek cross-over.
1, the internal wire - find some good quality 9Ns (8Ns at least) wire and connected it from your cross-over to the speaker elements. Make sure you, do it very carefully, use good quality solder to weld it directly to the tweeters, mid-range and your base speakers.
2, put a round wooden pole, 1 to 1.5 inch in diameter, to the side of your tweeter. This is to reduce cancellation, which is to avoid the frequency to do a wrap around. Similiar to the effect currently used by the new 801N series.
There are a few more tweaker's idea, however, I won't go into more details. Try these out and if it works and if you like more, email me, I'll reply.
By the way, most of these ideas are from an editor of a major Southeast Asia magazine who published the article in the magazine a while ago.
Have fun tweaking.