The original speaker specs were 170 watts and 400 watts peak....2 copper wind VC.
The CHT-12 is a ported subwoofer so this makes it much more difficult to find a replacement. You would need to measure the inside of the cabinet to get the internal volume. Also measure the inside of the port.
With these measurements you can then use Winisd to model some drivers. Randomly selecting a replacement driver is not good when dealing with a ported subwoofer cabinet. Make sure to read the specifications for the exact cut out of the driver so you know it will fit properly. Not just the width but also depth.