New to the site. My buddy found some Old Rockford Fosgate 15" subs at his moms house and is looking to sell them. They are new in the box but are probably 15 years old. They are in a cardboard colored and blue box and say series 1 on them. Are these subs any good? How much would be a good price to buy them for if there decent. I cant find anywhere online with info on these subwoofers so any help would be greatly appreciated. Thanks.