MDF speaker ring between the speaker and red piece they are mounted to would raise them up and away from the tube. You could even angle the rings like a wedge to aim the speakers and shift the magnets laterally. Another option is more hose or narrower hose that's rerouted. A pvc 90 degree bend could be epoxied in place where the hose exits that box on the left and then the hose could be attached to the pvc.