We have added foam plugs into all our vented products. Be it Subwoofers or Speakers. When you first unbox your new product, you will find that the foam plug is already inserted into the port.
How do I remove it?
Simply pinch the foam with your fingers and gently wiggle it from side to side to get it out. They will stick pretty firmly in there, so as to avoid air leakage should you choose to use the products with the foam plugs installed.