I once owned the Legacy Focus. It is a very dynamic speaker.
Usually when a speaker is rear ported it is better not to place it too close to the back wall. Perhaps experiment, move them out 2 feet or more to find that bass sound you want. Then place the Focus feet on some type of gliders that will allow you to move them back and forth when done using them.
You can try plugging the port holes, but I don’t think you will like the sound.
ozzy