Believe me, it'll be loud.
I recall my type 85 RS2-engined Coupe Quattro (B2) with single silencer Scorpion.
It was loud as hell on a run, drove me half senseless, I ended up buying a new centre section with an extra silencer like the OEM Audi system.
Bearing in mind it was an I5, which is a lot more forgiving than an I4, the 1,8T will be LOUD.