Where to get a crossover upgrade rebuild for B&W Matrix 802s3 Speakers?

I remember North Creek Audio and he liked to use Scan Speak speakers.

Most all production speaker could use a crossover improvement.  Top of the line crossover components will get very expensive. It also depends on the number of drivers weather it a two way or 3 way crossover. Capacitors depending on the type can get very large depend on the value and the material. Flat wound inductors also can be costly. It all depend on the speaker. Most common tweeters were 104 mm front bezel and there are many options for that size.

Good Luck 

http://www.troelsgravesen.dk/B&W-802s3_Upgrade.htm

These speakers, like a number of Infinity and some Focals I’ve personally measured, are good candidates for a crossover redesign as opposed to 1:1 parts replacements. I’d avoid doing parts swapping for the sake of doing part swapping.

I'm not sure why the link above isn't working correctly, but try going from here:

http://www.troelsgravesen.dk/Diy_Loudspeaker_Projects.htm#PAGE_INDEX

I can help you with any questions that you might have. I have original schematics, fairly straight forward crossovers, they will respond to improvements. Need to know what you are trying to achieve, how do you want them to sound different? How much do you want to spend on parts? I've done alot of this and am happy to help. Tim