Advice on active 6 dB crossover

[ostie01]

Hi. I have 4 way speaker with active rane crossover. I use two of them
I wanted to use both in 4 way mono cofiguration buth since they are not the same generation one is more detailled than the other.I'm now using them in serie.What I mean is one is for woofer and low mid and the other is for high mid and tweeter. I use 4 power amp.I would like to go passive between high mid and tweeter so I could use just one crossover configured in 3 way stereo.Can I just add a poly cap between high mid ant tweeter to have 6dB slope and have 24 dB slope between woofer and low mid and low mid and high mid and 6dB
between high mid and tweeter. I don't know a lot about rane product and I don't know are good they are. As a project, I would like to build a 4 way 6dB electronic crossover with the best parts I could find but why active are always 24dB.On many website,the 6dB passive is always consided the best choice but could not find 6dB active crossover project. Is a 6dB active a good choice ????. Thanks.