Beyerdynamic DTX 100 In-Ear Sound Isolating Earphones in Black. Portable sound today is reaching an enjoyment level that has never been before. Beyerdynamic's DTX 100 are a prime example of modern engineering for sound on the move. Sound isolation together with special hifi tuned one way dynamic drivers with neodymium magnets create lower frequencies so deep you will have to hold on to something. Matched with an equivalent high-end reproduction, the DTX 100 offer a balanced and clear listening experience.