I've got an idea how to do it without losing stereo sound by having 2 identical systems next to each other.
Split the 1/8" stereo output to 2 mono 1/8" outputs and put 1 into the sound bar on the Left monitor and 1 to the sound bar on the Right monitor.
You should be able to either buy 2 x 1 metre+ mono leads + a combiner adapter to plug into the stereo output or even a lead that does the whole thing in 1.
That way, you get a wider stereo image because you're using both sound bars equally with the Left sound bar handling the Left audio output and the Right sound bar handling the Right audio output instead of having 2 stereo sources right next to each other.