You can expect nice, flat response from bass-reflex speakers, but it would be even better to put them in a Pi cornerhorn. Cornerhorns operate in approximately eighth space, although they aren't exactly that because you have a ceiling. So they're greater than eighth space at the very lowest frequencies. And they are similar to a conical horn flare - stand back and look at the two walls of the corner together with the floor and the ceiling. Looks just like a huge horn, doesn't it? It's a linear expansion (conical) horn with a very large flare and mouth.

Basically, what this does for you is two fold. First, you have the properties of cornerhorn loading, which will boost your bass. Secondly, you have a reflector that will direct the source into the listening environment. This will provide "gain" through the midbass and midrange frequencies, simply by virtue of the fact that distibution is not omnidirectional, but is rather directed into the listening room. Between the two of these effects, you will increase speaker output from the bottom octave through the midrange frequencies.

Basically, my conclusion is that I'd be happy with your Vitavox speakers in either a PiAligned bass-reflex speaker or a Pi cornerhorn.