I personally have a Blueprint driver, the 1803. Their new website is www.missiondigital.net Yesterday I got its excursion up to around 3" peak to peak. It was WELL below tuning, 12hz, which I believe is the resonant frequency of the human body, otherwise with the low power I am giving it, I would never been able to make it excur so much.Anyways, its really low efficiency. 93dB 1w/1m and has the cone area of a 15" speaker, yet the frame is for an 18" the surround is so large. It would match up well with a pair of Pi speakers, but only if you had 1kW or more going to the 1803.