crossover points are decided by the install and rest of the stereo. there is no set crossover point for any given setup.
I've been tweaking/tuning the past couple of days and have ended up setting the crossover to the roll off point of my k2 components which is at 60HZ.
at this setting the w6's sound really good. i noticed that anything above 80hz makes the w6 sound muddy when driven too hard.
when forcing the w6's to handle too much of the frequency range is when the sound began to degrade. my current setup is producing some really really clean bass.
i'm assuming the w7 will behave similarly if tuned properly. based on the information given by another user that teh w7 woofer is the same as teh fathom this makes sense ast he fathom is a true sub bass woofer and is meant to be handling the lowest range of the frequencies(i think below 30-40hz). I'm quite happy with teh 12w6 once i figured out the proper setttings.
also, just mounted my focal and have connected it to my system. first impression, very responsive, tight, cohesive sounding bass that integrates extremely well with my k2 kps'. i've noticed that even when turning the bass level up it still sounds really good. definitely don't get the lower frequencies but this is a very good subwoofer that blends really well with the mid bass.
i'm torn between the two as they both do what they do really well.
i will probably end up keeping both and switch between the two depending on my mood.
here's a thought, would like some input:
would it be possible and feasible to add a 3rd subwoofer amp for the focal and split the sub signal from the head unit.
add a filter/capacitor at 45hz(roll off point of the focal) and cross it over at somewhere between 100-150hz(focal freq resp is flat to 200hz for the 27kx) so that it's handling the upper bass range.
and then let the jl take over from 45hz and below.
i think this proposed setup could sound really really good.