Can’t seem to find the F3 of MB2.
Anyway I also looked at specs for Dynaudio C4, another speaker I have liked (say 7.5/10) and that has F3 < 30hz too.
So going back to original options, keen to get your view on
1. Going with something like Tempesta and getting a pair of High quality subs vs a speaker that goes to Under 30hz
2. If full range speaker, I want height to be under 45 and width within 12”. Keen to get your view on hybrid vs fully passive and what could each design look like.
Separately I am also hoping to try Rockport Atria in the next month or so. Here is what I have tried so far:
1. Paradigm 3F : it did not feel very clean. Plus my hearing is really sensitive to high notes and I feel I can’t tolerate any level of brightness.
2. KEF Reference 5: there was nothing obvious missing but somehow it didn’t feel like I got the three elements I was looking for: heft in the bass at low volume, clean & sweet mids and airy top notes
3. PMC Twenty5.26 and Contour 60 - there wasn’t a clear winner. I preferred bass of Contour but midrange of PMC. Didn’t love High notes of any of these two
4. Focal Sopra 2 and B&W 802 D3: Focal felt tight and precise. However lacked the soundstage of B&W. B&W had great wide soundstage. However didn’t quite have the separation of Focal. I also found focal to be a bit boomy, but that could just be the room.
It makes it difficult to make a good comparison when there's not much evidence of the measured performance. I'm kind of shocked that PMC only listed a frequency range with no +/- dB let alone response graphs. Being that they market heavily to the recording industry it's surprising. I can pretty much look at quoted specs and tell you if they are fairly accurate, especially if I know the drivers involved.
-3dB @25hz (a true 25hz, not with room gain added in for advertising) is really tough to achieve in a fully passive speaker without a larger woofer and big cabinet. It's possible with an 8" driver but the sensitivity will be very low with a moderate cabinet size. If the woofer is designed for a smaller cabinet then the moving mass of the cone and other parts really makes it difficult to drive. The bass may go deep but the control / definition isn't very good.
Moving up to a 9.5" (like the Satori W024) improves the sensitivity but it takes a fairly large cabinet to have a box tuning without peaking. This is bettered by the Scan-Speak 11" (more excursion and surface area) but again with a fairly large cabinet. The Scan-Speak has more limited upper end response than the Satori so the choice of midrange is more important; however, there is a good group of mids that will work fine with the woofer. If your target is 25hz the larger woofer with more excursion always wins in a passive speaker.
So,yes, the passive 3-way can be done as long as you're tolerant of a bigger cabinet. The alternative is using an active bass section which allows more flexibility - sealed box, smaller cabinet, wider choice of drivers, etc. The DSP amps also give you the ability to do room correction/EQ which is a huge factor. No matter how good a passive design is I have witnessed many times over a listening room wreaking havoc on the bass with large peaks. If you don't have any EQ correction available in your front end equipment then a speaker with active DSP is your best solution.
The Tempesta with outboard subs or integrated into a single cabinet is an excellent choice. The Epico could be done the same way as well. The floorstanding option would be within the dimensions you need.