Another whats my box tuned to? Pweeze

Picked up a big box local. Can somebody give me a rough estimate what im tuned at? Sounded like 36-38 but wasnt the best install either. Also a rough net volume is greatly appreciated. I think its around 8 cubes before displacement but i fail at math.

Box is 25x 38x20

Port 18 tall 4 wide 22 deep

3/4 with double front baffle

Thanks for any help. I can compensate u a few bux paypal i guess.