Sperm is produced in the prostate gland to which two sperm bladders are attached. An empty prostate system fills up with new sperm in a day. If the sperm is not sprayed out, the body breaks down the old sperm and makes fresh sperm. A prostate system is muscular and can squeeze itself like a lemon.
The balls do not play an active role in sperm production. They only produce the tiny spermatozoid cells that passively pass to the two bladders of the prostate. The prostate system is the actual sperm factory.