I would like to share my old L-36 subwoofer, we have been using it since 1996 loaded with Cerwin Vega L-1815, enclosure is made by MB.
"To get more undistorted output, the excursion limits have been increased to 1 1/2" peak-to-peak through the use of a new edge suspension and spider. The diaphragm is Kapok and Kevlar; light yet very strong. The voice coil is very long yet the motor efficiency is three to five times greater than any 18” unit we know of—including the neodymium-iron-boron units claiming such advances."
COMPONENTS: L-1815 18 inch elephant motor
NOMINAL IMPEDANCE: 8 ohms
USABLE FREQUENCY RESPONSE: 30-300 Hz
PEAK POWER: 2000 Watts
CONTINOUS PROGRAM POWER: 1000 Watts
E.I.A. POWER HANDLING: 750 Watts
SPL @ LW, 1 meter: 108 dB
PEAK SPL @ RATED INPUT (1 meter): 136 dB
POWER COMPRESSION @ MAX CONTINUOUS INPUT: 2 dB typical
BL FACTOR: 52 Tesla-Meters (31 lb magnet structure)