They would be fine for supplying low end for a football field, they are the black glass version with aluminum trim, they are 'weatherized' compared to lacquered ply, but I would not want to subject them to rain either. They have an Eminence sourced driver made for Klipsch, designated K-43. If they were stored on their back with the mouth pointed upwards, the suspension will have sagged in one direction.
In that picture they are stored the way they should be stored. More information can be found on the Klipsch forum.
There are people that have used them in a home, but there are not a 'subwoofer' as in reproducing what is common on disc today. As a high output bass bin for a 3 or 4 way speaker system, they do fine.
95% Synthetic bass since Y2K.