wait first off the pic looks as if he has a mono channel amp that will have 2 subs running on it each on their own channel. Second. If you hook 1 svc 4-ohm sub to 1 channel it isn’t going to go to 2 ohm. You have to treat it as if the 2 subs were 1 dvc 4-ohm sub. hook the pos of one sub to the neg of the other sub. then take the remaining pos and hook it to the pos on the amp and the remaining neg to the neg of the amp. Which will yield the 2-ohm load in 1 channel.
now correct me if I am wrong but I believe that is how you hook up 2 svc 4ohm subs to 2 ohms