I am building 3-4 cf BR's with a high efficiency woofer crossed to a horn tweeter around 2 kHz, and am considering using the Altec 406, a 10-inch with a large alnico magnet and 28 Hz Fs, used by Altec in the late 60's and early 70's. Anybody have their T/S parameters or efficiency (or sensitivity)? Recommendations for other drivers also appreciated. I would prefer something with at least 95db/w/m and good performance up to 3 or 4 kHz. The Altec 414 is certainly a candidate, although it would likely require a larger cabinet than the 406.
TIA,
Bob