I bought a pair of Altec speakers from ebay. Have found out 1 woofer no good, probably the voice coil no more centered. On magnet, printed A0622 YST0590

If someone knows what does it mean and the best way to fix this, please help.

The back of speaker cabinet, printed

Altec Lansing
High Fidelity Loud Speaker System 95

4 ohm nominal
125 watts maximum program