need more smoothness

It's a matter of the personal tastes that are currently somehow statistically spreaded throughout speaker manufacturers.
The largest differences heard in speakers in top-end are in tweeter designes. I prefere aluminium dome and someone would prefere soft textile.
I think to agree with Gmood1 that basically you havn't got the speaker you realy want.

I can't believe it. I just went to the Bowers and Wilkens website and that's what they recommend... stick felt on their speakers!

I think anything with a metal dome is sheer pain on the ears. They should keep the material for making cars instead

Or they could just make cymbals and brass instruments out of silk.

Some of the smoothest sounding speakers available use metal tweeters. All metal does not resonate at the same frequency. Metal can be treated to alter its resonate characteristics. etc etc.

You really need to list your entire system. Also a detailed description of your listening room and placement would help.

B&W's can sound wonderfully smooth with the right gear. Every link in the chain matters with B&W's. That said, there are smoother sounding speakers available, many of which aren't as demanding of the upstream components.