I owned a pair of these for a year and were the first Definitive speakers I ever owned (it was only for a year because I saw a deal for some BP10B's that was too good to resist so I upgraded). The first time I set them up I remember hearing that typical American speaker sound for the first time since I worked in an expensive Hi-Fi shop while I was in school. The way the bass was so deep and controlled whilst the treble was so clear and extended well into and beyond high frequencies I could not hear is captivating. The sound makes everything exciting, they add drama to everything and sound particularly atmospheric and typically American sounding with horns and violins. Not only this, but these are bipolar which is not a term English people are used to hearing describe floor standing loudspeakers. It is heard of when talking about rear surround speakers since of course you want to spread the surround sound around the room so it makes sense to have more than one set of drivers facing different directions on the same speaker. Well, Definitive have been doing this for a long time. I believe their first product was the BP10 (not the B version) and so we have the smaller version of that here but the newer B version.
The B means it has some changes. Important changes are butyl rubber surrounds on the woofers that doesn't go white/brown in colour with age and a tweeter that is now Aluminium domed rather than silk which sounds so much better and never sounds shrill like the old ones. Minor changes include a better fixing method for the top gloss panel and grooves on the top for the sock cord to exit at the top.
The theory of bipolar floor standing speakers goes something like...
If you have them near a flat back wall and angled in towards the listener then the reflected sound waves create a sense of space and realism. Definitive recommend placing them 4" to 24" away from the wall. I found that the closer you put them to the wall the more bass you get but the further away you get a better sound distribution.
Indeed been bipolar does make them sound bigger and less directional which some people don't like. This has other advantages though. It means the "sweet spot" is much bigger so more people in the room get a good stereo effect rather than having to sit dead in the middle to get the full effect. This really does work and is great if you often share your music/movie experience with others. Also, you have another driver back there so there is the potential for deeper, louder and distortion free bass.
I have grown to love the bipolar sound and now when I listen to traditional speakers it sounds so flat and lacking that 3-dimensional soundscape.
The bass specification on these speakers is probably true in that it will produce sound down to 22Hz but you won't hear it unless you have it heavily tuned up using a graphic equalizer. For pure direct stereo playback they don't have any more apparent bass than normal speakers. The bass reproduction method is a unique design since the cabinet is a cross between computer synthesised transmission design and vented. The vent is down low on the back.
I was actually disappointed with the bass output of these speakers and its one of the reasons I gave this product 4 stars and the main reason why I upgraded.
They have Linkwitz Riley crossovers which provides phase matching between woofer and tweeter as well as giving a very linear response over the frequency range. The terminals are on the underneath and there is a slot for the speaker cable to come out so that you essentially have speaker cloth all the way around and it isn't covered by anything. These really do look very smart in any room and there is only one problem I have found; my pet cat loves to try and claw them!
The build quality is good but not exceptional. It certainly improves on the newer speakers. These are 0.5 inch thick chipboard (or similar) sides and 1 inch thick front and back baffles. There is a brace between the side panels halfway up the inside of the speaker. One incidental advantage of the bipolar design is that since the woofers move in phase there are virtually no vibrations in the baffles as it cancels out. This then also provides a rock steady mount for the tweeters.
Full specs are:
38"H x 7"W x 11"D (889mm H x 178mm W x 279mm D)
22Hz - 30 kHz
Compatible with 8 Ohm output
Recommended Associated Amplification Power:
Two 1" Aluminum dome tweeters and Two 5-1/4" bass/midrange drivers
44lbs (20kg) each