Whooaaaa hold up!
I only skimmed over the thread admittedly so I may have missed something, but unless you are actually using the Morel drivers that were meant for that crossover, do NOT buy that crossover.
Unless the TS specs and frequency response are a dead match for that of the Morel drivers, that crossover is not going to give you anywhere near optimal results. In fact it would probably sound for worse than simply running two-way active. If you use a driver that's not meant for the passive crossover then chances are everything from Frequency response, to impedance curve, to distortion characteristics to sensitivity are going to be VERY different.
* The crossovers are built to level match the appropriate Morel tweeter, midrange and midbass and does so by attenuating some of those drivers by a certain degree so that they are all at an even level. If your drivers have an uneven sensitivity then the drivers will not be properly level matched - even if you have gain adjustment on the crossovers they are usually only by 1dB or 2dB increments which are usually still not good enough to get it as accurate as you want it.
* Incorrect impedance curves will throw off the entire crossover point and slope, and could throw it off to the point where a 3khz crossover point on your tweeter could change to 1.5khz, as a result frying your tweeter (or to 5khz, causing a massive hole).
* If the crossover has a specific slope tailored to the FR of the original drivers, then if your drivers have a totally different FR (which they probably will) then the slope wont match and the integration will be either peaky or filled with holes.
To cut a long story short you NEVER want to use a passive crossover for any drivers other than the ones it's designed for. Best case scenario it'll sound bad, worst case scenario it may cause damage to your components. If the drivers you use are DIY drivers sold by Madisound then they actually offer a service whereby they will custom-design a 3-way passive crossover for you. For an extra cost they can and will even assemble it for you using your choice of components. If you need to go the passive route it is a much better option then buying a random crossover and hoping it will work, and it will probably work out cheaper too.
Edited by Tritty, 16 December 2012 - 09:29 PM.