I have checked this out but I think it's 8inch and on the small side.f1only said:The Tannoy is a more all rounder IMHO better with music, where as the BK is more a home cinema Subwoofer. In the end decision is yours of course, dependant on your listening tastes / preferences.
How about a Monitor subwoofer at a good price to go with your other speakers, so possibly This used subwoofer may fit the bill? & a link to specs
Regards