the info i know
13 inch Subwoofer: Polyglass 33 K Subwoofer for bass-reflex enclosure Woofer 33 K 330mm (13) subwoofer, 77mm (3) v.coil, 180mm (7) magnet Midrange - Tweeter - Crossover - Max. power handling 800 W Nom. power handling 400 W Sensitivity (2.8 V / 1m) 94,5 dB Frequency response 30 Hz * - 1 kHz *Depend on load Fs 38,4 Hz Re 3,7 ohms Qes 0,44 Qms 7,19 Qts 0,41 Dia 26,5 cm Mms 141,5 g Lvc 2,28 mH Hbob 28 mm Hgap 10 mm Xmax 9 mm Sd 551,5 cm2 Vas 51,1 l BL 17,0 N/A Folding diameter 288 mm Mounting depth 149 mm Sealed enclosure (l.) - Bass-reflex enclosure (l.)

 

33K polyglass?. home audio woofer?

 

befor the 33kx was the 33k i think it was made for a 1 1/2cft box with a 8" port at 3 " but i do not know