Electronic Noob, crossover Problems

[Deorum]

Hello, and good to find you.
Im an noob with electronics, but eager and quick to learn.

I'm upgrading my speakers, i already changed the speakers.
I think that the biggest benefit would be an improved crossover, since the current one look very cheapo, and after all the electrolytic capacitors are over 10 years old and totally worn off.

The current cut off freqs are 800hz/3000hz (3 way loudspeaker).

Since i changed the speakers, after some search i ended up that if im gonna build an new crossover it would be better to lower the cut off freq to 700hz (maybe even lower, but i prefer to be cautious). It is also mandatory to lower the volume of the midrange -2db (maybe -3db), since its a bit more sensitive than the rest of the system.

Specs for midrange and twitter are here.
https://www.solen.ca/pdf/peerless/812774.pdf
http://www.madisound.com/pdf/peerless/821615.pdf

Unfortunately, i dont have specs for the woofer, but its an 8ohm 12" woofer, now cut @ 800hz (because old midrange couldnt get lower).

Now to the questions!

Where do i start? (as simple as that

[Deorum]

Cant find the edit button :-P

Also wanted to ask you (maybe by looking the specs i've linked above) what do you think for the cut freqs that i've chosen 700/3000, and what do you think about the -2db to the midrange.

[BWRX]

If you're changing the drivers in your 3 way speakers than you should change the cutoff frequencies to accommodate the new drivers. Common crossover frequencies are 2-3kHz for mid/treble and 100-300Hz for bass/mid.

Here's an active crossover project from Rod Elliot that is pretty popular: http://sound.westhost.com/project09.htm