I've fitted those exact 2 sets of speakers in the front doors of my TT (although you've listed the 13cm version of the 2 way and I fitted the 16.5cm version) - neither of them are a direct replacement of the stock speakers, especially a single unit and not the set. Also, the B&O speaker is a dual coil speaker, so you'll really struggle to find an alternative speaker that works perfectly with the setup. I'll put my thoughts down on each separately (from my perspective)
A. 2 way setup - easier to fit if you started with the Audi Sound System (ASS) as you can utilise the existing wires to the door (there's only 1 pair feeding into the door with this setup). The 16.5cm speaker in the door will use the exact same mounting screws and (apart from clipping off a small plastic pin) fits straight in. Tweeters will need a little bit of work to fit in the stock locations. IIRC I needed to slightly reduce the size of the tweeter clip on case by sanding it before fixing it in with a lot of hot glue - sounds like a bodge, but isn't lol.
B. 3 way setup - woofer and tweeter, exactly the same to fit as the 2 way. The biggest issue here is getting a 2nd set of wires into the door for the midrange. I ended up buying some male and female crimp pins for the door plugs and running new wires in. You'll also need to fabricate a speaker mount for the midrange and (if you started with a car that doesn't have B&O) the grille for the midrange will need swapping out. I made an MDF speaker mount but am looking to 3d model and print one instead (as I'm a geek lol)
Finally, you'll find that (from changing from the ASS) the replacement speakers (the Focals at least) are less sensitive and will be quieter than stock unless you run a separate amplifier.
I know some of this doesn't apply to the OP's blown speaker issue, but hopefully it'll help the OP and the replies too.
