Quote Originally Posted by Macca View Post
What's the reference for it going down to 21hz? Does not seem to be any spec about this on the B&W site. My guess is that it is not doing much useful under 50hz.

If you want proper sub bass you'll need a big REL, or a Paradigm. Very few subs have useful output below 40hz and those that do tend to be large and expensive.
From the PV1 Brochure "±3dB 21Hz – 31/110Hz adjustable (EQ at i)"