Don’t buy the JL E112s. I have two and both have broken a number of times. Using their internal highpass crossover adds a lot of electrical noise to the system (buzz/hum). I will replace mine with a different brand sooner than later.
Running subs under your speakers without a highpass crossover will make your system worse. the timing will never be right.
Running subs with a proper highpass will take them to a new level. The JL CR-1 would do the trick. Add any quality sub at that point.
based on the measurements the Sabrina needs subs unless you are placing them less than 3’ from the front wall based of the -10db point and room gain.