An electro-acoustic transducer has an electro-magnetically driven moving dome and a phase plug having a body and a dome-interface surface, with a compression cavity formed between the dome and the dome-interface surface. The phase plug includes at least first and second annular slots beginning at the dome-interface surface and extending a first depth into the body of the phase plug. The first and second slots are separated by a bridge element at the dome-interface surface and joined by a first bridge passage at the first depth beneath the dome-interface surface. The phase plug also includes an exit slot coupling the bridge passage to a throat at a second depth in the body of the phase plug.