Yes, those are great subs. They do require a highpass crossover I believe. so that means you need an amp and preamp or an integrated with pre-out and amp-in. This way one can free up the harbeth from anything below about 80Hz so it can concentrate on the mid-range. Search out what Bob Reynolds has to say about this type of set up here on agone. What he says makes a lot to sence regarding highpass filters (crossovers) and distortion. As for me, I think the sound of the radial driver is so delicious down to 45hz, I thought it a pitty to use a high pass--but I might try it in the future. Also check out the Vandersteen website, It will explain better than I can regarding the philosophy behind their subs and how they work.
Cheers!