Sound Stage and Imaging

@mijostyn I was partially kidding with the screws. Just a bit unusual to see them as exposed as they are in any speaker over say $100 pair. Most would make the REAR panel removable (with 'under' mounted bass driver). 

@kraftwerkturbo I would probably go for the 2TD-X - still inexpensive compared to "finished" speakers

Kits: not afraid at all. build quite a few back then (very nice finish Eton 10 (in the 80's; GREAT sounding Focal Onyx (still dreaming of it, actually though about recreating it). Recently my sub: https://drive.google.com/file/d/1HPeV4E7xUvmPwq5cBFlI633_yk-dXJy2/view?usp=drive_link

@grislybutter just checked the specs of the 2TD-X. Rated at 100W.

As with every small speaker: do they have enough (even with help from big sub under 50 or (pushing it) 80 Hz) in them to fill a large (volume vise think 40x40x10) room with 100+ db (think Wagner size orchestra authentic SPL)?

@kraftwerkturbo 

Yes, it is unusual, but the British are unusual. I can say that the P3's construction is first class using the best materials. I have never seen tighter miters. 

@grislybutter 

I did not mean it to be harsh at all. He is concerned about crosstalk. Headphones are the best way to defeat it. 

I think building your own speakers is a wonderful thing to do. There are hundreds of excellent drivers available, your computer gives you the power to make important measurements and digital signal processing makes time alignment and phase accurate crossovers a breeze. I know exactly what I would do for dynamic speakers. Unfortunately, I am an ESL junky. All I have left to do is the subwoofers and they are the hardest enclosure to get right.