I gave the specs for the 18 inch drivers. Here's the specs for the 15 inch driver I have>Re 6.56 Ohms fs 22.2 Hz
Le 6.31 mH
QM 9.08
QE 0.53
QT 0.50
Xmax 14.29 mm
Pmax 225 Watts
Coil Diameter 2.50 Inches
Magnet Weight 90 ounces
Efficiency 0.59 %
SPL 89.7 dB 1W-1m
Dave