PMC make great speakers - I read somewhere that Brian May uses them. However, your comparison may not be fair.....the FB1+ is a two way design and this is not nearly as good as a three way design such as the B&W 800 series.
Frequency range specifications are NOT a good way to judge a speaker...low distortion, good dispersion, high dynamic range and accuracy & timbre under various operating levels is much more important.
Having said this, if you were to compare B&W 800 range to the PMC IB2S or MB2S then I think you would find PMC are comparable...indeed many would say significantly better...especially the dome mid range which was designed by PMC to compete with ATC in the professional studio markets where ATC dominate and have become widely accepted as having the best mid range driver in the world (PMC used the ATC mid range driver until they developed their own).
Frequency range specifications are NOT a good way to judge a speaker...low distortion, good dispersion, high dynamic range and accuracy & timbre under various operating levels is much more important.
Having said this, if you were to compare B&W 800 range to the PMC IB2S or MB2S then I think you would find PMC are comparable...indeed many would say significantly better...especially the dome mid range which was designed by PMC to compete with ATC in the professional studio markets where ATC dominate and have become widely accepted as having the best mid range driver in the world (PMC used the ATC mid range driver until they developed their own).