The drive units look kind of small can they really produce enough bass?

Yes they can!

The Sibelius is perfectly balanced right down to the lower registers.

The Valentini has beautifully detailed bass but for some they might want a little more lower depth, in this case we advise The Sibelius or (if it is going to be used for movie soundtrack reproduction, then (although it is not part of our purest philosophy) you should possibly consider adding a sub-woofer to the Valentini’s to take over the lower bass from 80Hz downwards.

The choice is yours.

The Valentini and The Sibelius