From oldest to newest:
In order from oldest to newest, to the best of my ability:
805 Matrix, 805 Nautilus, Signature 805 ( a fancy version of 805N ) , and finally the 805S is the newest, and bosts all the newest technology that trickled down from their flagship D-series. I have had 805M and 805N and there was a definite improvement. Have fun, don't worry......
I just got a pair of the 805s.
They have a review from some mag on the B&W website about it, and mention the Signature 805 in comparison.
Generally to most current is the best sounding. They actually did improve it over the years.
(I like to sound, but do admit that I got a subwoofer to touch up the bottom end a bit. For Rock, Classic Organ, even the bass line in a Jazz group.. the bass is wanting a little bit. And I am not a low frequency maniac either! Just you gotta sit close to the 805s, or get some tone controls. My low frequency tone control is a subwoofer.)
"Is the 805S better than or equal to the 805 signature?"
Depends on who you ask. I've owned both. Both did things that I liked. My preference, I liked the sig 805 better. The 805S is still a fantastic speaker. Alot of people disagree with me. I think partly because most want to like the new stuff out there.
I have these speakers pair of 805N, and a pair of 805S I bought the new. Started out with 805N as a stereo set up then upgraded room 5.1 So bought the 805S and HTM4 for center. These are outstanding speakers. But lack low bass. I would not recommend these speakers without using a sub. Let me add this too. I would add a self powered sub to all speakers. This really takes the low end of the main amps and speakers.