Rare 9 inch drivers with tweeter on frame in front of bass-driver dust cap.
Not the first time I find a good co-axial driver outperforms a good full ranger. E.g. Visaton B200, Fostex etc.
Peerless did not bother replying regarding driver parameters but sensitivity seems very high – about 95db.
Original Jensen caps (which measure fine) supplied but have replaced them just in case. – see image.