I own a REL B2 Britannia subwoofer, I hated subs all my life until It arrived back in 2013, I bought it used back then for around $1200. This is the best addition to my system as my speakers are Dynaudio Contour 3.0 which are fast speakers with 8 inch drivers, the SpkOn connection is unique to REL and I think if not for this type of connection I wouldnt even run a sub at all. REL B2 when inserted properly frees the main speakers and allows them to play more musically and the whole system is anchored by this foundation of low end information and musical coherence that is connected with such synergy the whole system is elevated to a new performance level.
I wouldnt hesitate to purchase one, you can even contact REL in the Berkley CA area to get a newer replacement driver which was a upgrade for the original. I paid around $350 (7 years ago) for this. Also, I have owned one of the T6 subs I think it was around $2500 and was very nice but my REL B2 is very special and its Cherry wood veneer finish match my main speakers perfectly.
One REL is all you need Especially if its a B1 or B2.
Matt M.

