Dynaudio Confidence C1 and Vivid V1.5

Branislav:
B1's bass is not weak but a little thin, still, its a 3 way and it goes a little deeper and smoother than C1 MKII. the "perceived" sound of B1's bass to my ears was incredibly clean and without any sort of cabinet resonance. While Dynaudio uses a traditional woofer with wood cabinet, generally, it gives a little more decay

I personally vote for the Vivids. All models are smoothly enough and sounds extremely natural! Sound spectrum are very coherent from top to bottom. They are one of the best in this aspects. But they can sound totally different with different components, placement, cable etc.
They are very sensitive in placement & can sound plenty bass, or can do no bass at all, or even boomy. So different audiophile can experience differently, depending on how you get along with them!

I tried the Vivid Audio V1.5 at my living room and fell in love. Just... I lack the lower octave. I'm considering adding a subwoofer to complement them. Would you say this is a good option?

My living room is 30m2.

I also tried the Vivido Audio B1 but the bass was completely out of control and the dynamics was exaggerated: always having the need to turn the volume up and down during the same piece.

The B1 had much more detail than the V1.5... and I would by them if it weren't for these 2 problems...

Nuno