Hey, I've just purchased 2 of the OPTI1533Ds. I found the specs for it on another website but when entering those specs into WinISD it told me the specs didn't match up. WinISD is epic for tuning, tells you port sizes etc. what freq. you'll get n so on, but you need to have the correct specs in order for it to work.
Could you take a picture of the entire sheet? I'd love to get my hands on the true specifications for this sub.