DE built-in speakers feature a very wide frequency range with a high power capacity. They deliver a transparent, precise sound pattern thanks to sophisticated electronic equalization. Our DE speakers can be quickly and securely mounted in hollow wall and ceiling constructions. Our EG Series of back boxes can be used to reduce sound transmission to adjacent rooms. We also recommend using back boxes when installing devices in acoustic ceilings, solid walls or furniture. The plastic back boxes in our EGB series are designed for the integration of speakers into concrete ceilings.