Hi Guys, sorry I'm late to this party, but here are a few thoughts and I'll add specific responses as reply's to quoted posts.
First, congratulations Intermechanico, you are making great progress!
You've been well counseled so far, and it's great to see the support for yet another full-active conversion going on. As you are seeing from your early results, it's pretty magical compared to a passive setup.
One comment I'll make about crossovers and crossover points is that the panels, even really big ones like my monoliths, do not play both loud and deep. I made measurements on both the Monoliths and the SL3 panels and I found that the SL3 panel really would not handle much below 320Hz cleanly at 90dB, and the Monolith could only go to 260Hz before the distortion started rising. So my crossovers are now set at 256Hz with a fourth order slope (LR) for the HP on the Monoliths and at 400Hz first order (BS) slope for the SL3XC panel.
I had been running the Monoliths set higher (around 315Hz) which gave me good headroom in the crossover region, but I prefer to let the panel go a bit deeper in the mid-bass and just not crank it as hard.
For your Vista panel, I'd guess a good starting point would indeed be around the 350 to 400Hz range and use a steep slope in the miniDSP. One of the advantages an active brings is you can go with super steep xovers with very little penalty. I believe Sanders uses 48dB/octave LR in his active setups.
As for the woofer, my first reaction is to suggest you keep it simple and focused on giving you nice clean output between 50 - 60Hz and 500Hz and use two subs elsewhere in the room to give you balanced bass performance. As other have noted, the location where the panels perform their best is not likely = to the ideal low-end locations.
I did a test with four cheap subs that just blew me away at how good bass can be if you position the subs for smooth in-room response. Throw DSP on top of that, and you will not believe it yourself.
Anyway, my advice is look for a woofer driver that has excellent performance up to 800Hz or so, that will exclude pretty much anything labeled for 'sub' duties. You want a lightweight cone, low THD and no breakups until above 800Hz. This means it will likely only go down to 50 or so, maybe higher. That's fine, as you then feed everything below that to the subs.
Given that a woofer handling content well up to 500Hz should definitely be pointing in the same direction as the panel.
Don't sweat the woofer to panel physical alignment too much as you can tweak delays in the miniDSP. Just measure the impulse responses of each individually and adjust delay and phase as needed. Once you perfectly align the two impulses, more magic happens
